“There are four things that motivate open source development teams:
1. The challenge/puzzle of programming, 2. Need for the software, 3. Personal advancement, 4. Belief in open source” — Bruce Momjian.
On PostgreSQL and the challenges of motivating and managing open source teams, I have interviewed Bruce Momjian, Senior Database Architect at EnterpriseDB, and Co-founder of the PostgreSQL Global Development Group and Core Contributor.
Q1. How did you manage to transform PostgreSQL from an abandoned academic project into a commercially viable, now enterprise relational database?
Bruce Momjian: Ever since I was a developer of database applications, I have been interested in how SQL databases work internally. In 1996, Postgres was the only open source database available that was like the commercial ones I used at work. And I could look at the Postgres code and see how SQL was processed.
At the time, I also kind of had a boring job, or at least a non-challenging one, writing database reports and applications. So getting to know Postgres was exciting and helped me grow as a developer. I started getting more involved with Postgres. I took over the Postgres website from the university, reading bug reports and fixes, and I started interacting with other developers through the website. Fortunately, I got to know other developers who also found Postgres attractive and exciting, and together we assembled a group of people with similar interests.
We had a small user community at the time, but found enough developers to keep the database feature set moving forward.
As we got more users, we got more developers. Then commercial support opportunities began to grow, helping foster a rich ecosystem of users, developers and support companies that created a self-reinforcing structure that in turn continued to drive growth.
You look at Postgres now and it looks like there was some grand plan. But in fact, it was just a matter of setting up the some structure and continuing to make sure all the aspects continued to efficiently reinforce each other.
Q2. What are the current activities and projects of the PostgreSQL community Global Development Group?
Bruce Momjian: We are working on finalizing the version 9.4 beta, which will feature greatly improved JSON capabilities and lots of other stuff. We hope to release 9.4 in September/October of this year.
Q3. How do you manage motivating and managing open source teams?
Bruce Momjian: There are four things that motivate open source development teams:
* The challenge/puzzle of programming
* Need for the software
* Personal advancement
* Belief in open source
Our developers are motivated by a combination of these. Plus, our community members are very supportive of one another, meaning that working on Postgres is seen as something that gives contributors a sense of purpose and value.
I couldn’t tell you the mix of motivations that drive any one individual and I doubt many people you were to ask could answer the question simply. But it’s clear that a mixture of these motivations really drives everything we do, even if we can’t articulate exactly which are most important at any one time.
Q4. What is the technical roadmap for PostgreSQL?
Bruce Momjian: We are continuing to work on handling NoSQL-like workloads better. Our plans for expanded JSON support in 9.4 are part of that.
We need greater parallelism, particularly to allow a single query to make better user of all the server’s resources.
We have made some small steps in this area in v9.3 and plan to in v9.4, but there is still much work to be done.
We are also focused on data federation, allowing Postgres to access data from other data sources.
We already support many data interfaces, but they need improvement, and we need to add the ability to push joins and aggregates to foreign data sources, where applicable.
I should add that Evan Quinn, an analyst at Enterprise Management Associates, wrote a terrific research report, PostgreSQL: The Quite Giant of Enterprise Database, and included some information on plans for 9.4.
Q5. How do managers and executives view Postgres, and particularly how they make Postgres deployment decisions?
Bruce Momjian: In the early years, users that had little or no money, and organizations with heavy data needs and small profit margins drove the adoption of Postgres. These users were willing to overlook Postgres’ limitations.
Now that Postgres has filled out its feature set, almost every user segment using relational databases is considering Postgres. For management, cost savings are key. For engineers, it’s Postgres’ technology, ease of use and flexibility.
Q6. What is your role at EnterpriseDB?
Bruce Momjian: My primary responsibility at EnterpriseDB is to help the Postgres community.
EnterpriseDB supports my work as a core team member and I play an active role in the overall decision-making and the organization of community initiatives. I also travel frequently to conferences worldwide, delivering presentations on advances in Postgres and leading Postgres training sessions. At EnterpriseDB, I occasionally do trainings, help with tech support, attend conferences as a Postgres ambassador and visit customers. And of course, do some PR and interviews, like this one.
Q7. Has PostgreSQL still something in common with the original Ingres project at the University of California, Berkeley?
Bruce Momjian: Not really. There is no Ingres code in Postgres though I think the psql terminal SQL tool is similar to the one in Ingres.
Q8. If you had to compare PostgreSQL with MySQL and MariaDB, what would be the differentiators?
Bruce Momjian: The original focus of MySQL was simple read-only queries. While it has improved since then, it has struggled to go beyond that. Postgres has always targeted the middle-level SQL workload, and is now targeting high-end usage, and the simple-usage cases of NoSQL.
MySQL certainly has greater adoption and application support. But in almost every other measure, Postgres is a better choice for most users. The good news is that people are finally starting to realize that.
Q9. How do you see the database market evolving? And how do you position PostgreSQL in such database market?
Bruce Momjian: We are in close communication with our user community, with our developers reading and responding to email requests daily. That keeps our focus on users’ needs. Postgres, being an object-relational, extensible database, is well suited to being expanded to meet changing user workloads. I don’t think any other database has that level of flexibility and strong developer/user community interaction.
Qx. Would you like to add something?
Bruce Momjian: We had a strong PG NYC conference recently. I posted a summary about it here.
I think that conference highlights some significant trends for Postgres in the months ahead.
Bruce Momjian co-founded in 1996 the PostgreSQL community Global Development Group, the organization of volunteers that steer the development and release of the PostgreSQL open source database. Bruce played a key role in organizing like-minded database professionals to shepherd PostgreSQL from an abandoned academic project into a commercially viable, now enterprise-class relational database. He dedicates the bulk of his time organizing, educating and evangelizing within the open source database community while acting as Senior Database Architect for EnterpriseDB. Bruce began his career as a high school math and computer science teacher and still serves as an adjunct profession at Drexel University. After leaving high school education, Bruce worked for more than a decade as a database consultant building specialized applications for law firms. He then went on to work for the PostgreSQL community with the support of several private companies before joining EnterpriseDB in 2006 to continue his work in the community. Bruce holds a master’s degree from Arcadia University and earned his bachelor’s degree at Columbia University.
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“The Internet of Things is a good fit for NoSQL technologies, as you face the challenge of dealing with huge volumes of data over time. For businesses that wish to scale their IoT implementations and make use of the data that these networks create, NoSQL solutions are a better fit than RDBMS options.”–Mike Williams
I have interviewed Mike Williams, software director for i20 Water. Mike has an interesting use case for NoSQL in the area of water distribution networks. We also discussed how NoSQL can be used for the Internet of Things.
Q1. What is the business of i20 Water?
Mike Williams: i2O is the world’s leading developer of Smart Pressure Management solutions for water distribution networks.
Q2. What are the main benefits for utility companies?
Mike Williams: i2O’s Smart Pressure Management solutions optimise the performance of water distribution networks through improving network visibility, and enabling the remote control and automatic optimisation of network pressures.
These technology-enabled best practices deliver benefits in six key areas, with customers typically achieving return on investment in 6-18 months.
The opportunities for savings fall into two areas: on the network side, we see leakage reduction, energy savings and a big reduction in burst pipes.
For our utility customers, there are business-level returns as well based on improved customer service and operational cost savings. We also see customers being able to extend the life of their assets across the network as well, so they see a real long-term benefit to being able to control water pressure more accurately.
Q3. Do you have any metrics to share with us on the estimated volume of water saved by using your software?
Mike Williams: The best metric we can give is the simple volume of water that we help customers save: we currently help our customers to save over 235 Million Litres of water every day.
Q4. How can big data be used to reduce water leakage?
Mike Williams: The i2O system monitors and controls water pressure throughout a zone or network. This enables water companies to fully optimise water pressures remotely and automatically to meet agreed customer service levels throughout the network. The Big Data is all of this time-series data of pressures and flows (and other metrics) for lots of locations over years’ worth of points.
The solution continuously learns key characteristics within a Zone and then automatically controls the pressure within the Zone to achieve a stable target pressure at the critical point. This is achieved through a sophisticated mathematical algorithm, which automatically generates a control model. The control model is supplied ‘over the air’ from i2O software to the Pressure Reducing Valve (PRV) controller.
The control model is automatically updated if the software detects a significant change in the head loss characteristics. This ensures that no more pressure than is required enters the network on an ongoing basis. The i2O Automatic Optimisation solution is the world’s first – and most widely deployed – system for automatically optimising and remotely controlling water pressure in your network.
i2O’s Automatic PRV Optimisation has delivered significant results in hundreds of zones for major water companies worldwide.
Q5. Could you please describe your IT back-end infrastructure? What are the main challenges you have?
Mike Williams: We have an eco-system of distributed loosely coupled Services, each with access to numerous dedicated and tailored data stores.
These services collaborate through an Event-Driven Architecture (EDA) and a distributed Event Broker to deliver business services to our customers.
The main challenges are around the scalability of these services and the data stores where the vast amount of time-series data are held.
Due to the way we have architected our data, we have the ability to replay these events over history when we make changes to our products and services – we can use this historical data to analyse how devices on our networks respond to changes in circumstances, and measure what difference our new features would provide.
Q6. Why did you make the shift to NoSQL? What were you doing previously?
Mike Williams: The challenge was the overall scale–up of the whole platform. From both a technical and a business stand-point, we needed to scale up for the next years. Based on the number of devices that our customers had in place, and the number of new customers that we were projected to win, our RDBMS was not able to cope by design. Storing time-series data is a specialist need that column-oriented data stores are better suited to than traditional RDBMS row-oriented technologies. We were (and for some customers, still are) using MS SQL Server as the only data store. NoSQL technologies also better fit our data modelling needs such as searching, where we employ the ElasticSearch NoSQL solution in a clustered manner.
Q7. What is your experience of using a NoSQL database so far?
Mike Williams: So far it has been very positive. We had a learning curve to go up and the technologies themselves (Cassandra and ElasticSearch) have matured greatly in the last 18 months that we have been using them.
Q8. What does the future hold for Cassandra in your organisation? How are you using other database types as well?
Mike Williams: We moved over to using Cassandra as our main data store for time-series data – this was because it provides better support for columnar data, as well as meeting the requirement that we had around scale. We are committed to Cassandra for the foreseeable future and so it’s future is to grow alongside our business. We also use ElasticSearch as mentioned, as well as PostgresSQL when our specific data models dictate the use of tabular, relational data.
Q9. Do you work on the cross-over with the Internet of Things?
Mike Williams: Indeed we do as we produce intelligent devices that communicate with our Platform over the Internet (GPRS mobile network). The devices automatically sample for pressure, temperature and other information that can then be compared across the network.
The Internet of Things is a good fit for NoSQL technologies, as you face the challenge of dealing with huge volumes of data over time. For businesses that wish to scale their IoT implementations and make use of the data that these networks create, NoSQL solutions are a better fit than RDBMS options.
The ability to capture information from across our network has two key value propositions: the first is for our customers right now, as they can manage their water pressure more effectively. The second is the long term value that the data can provide. By being able to model and re-use historical data, we can offer much more value to customers than they can achieve by themselves. We can add new features to our platform, and demonstrate how these new features can provide greater opportunities to save money and water for customers.
Mike Williams is the software director for i20 Water. He has 25 years of experience working for innovative high-tech companies in finance, payments, process engineering and the environment, where he has focused on solving problems and translating business challenges into tangible technical solutions. Before joining i2O Water Mike was the Chief Software Architect and head of development for Bottomline Technologies, the leading supplier of banking transaction and payments software.
Mike is also an Agile Coach and has helped transform numerous businesses as they become Agile in their approaches to business as a whole and not just software development. Mike is the organiser and founder of the Agile South Coast group.
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“Spring for Apache Hadoop together with Spring XD is used by many large organizations for developing new big data apps for stream processing and using HDFS for storage.”–Thomas Risberg.
On Spring for Apache Hadoop, I have interviewed Thomas Risberg, Software Engineer focusing on Big Data at Pivotal.
Q1. What is new with the current Spring for Apache Hadoop?
Thomas Risberg: The main focus for Spring for Apache Hadoop version 2.0 is to support new distributions based on Hadoop v2 including support for YARN. We provide backwards compatibility with Hadoop v1 based distributions, so as an end-user you can choose when to move to a new Hadoop version.
In Spring for Apache Hadoop 2.0 we are adding YARN application development support in addition to improvements in the HDFS and MapReduce support. We are introducing a Spring Boot based programming model for easy YARN app development. The main goal is to provide a simplified development experience so the developer can focus on getting the business logic implemented and not having to worry about the “plumbing”.
Q2. How do you measure the “effectiveness” of how Spring for Apache Hadoop simplifies developing Apache Hadoop?
Thomas Risberg: The main differentiator would be developer productivity where Spring for Apache Hadoop provides support for the infrastructure plumbing code and configuration allowing the developer to focus on code that brings business value. The most common measurement would be how long completing a project would take compared to the same project being developed without Spring.
Q3. What is the rationale for offering a unified configuration model and an APIs for using HDFS, MapReduce, Pig, and Hive?
Thomas Risberg: Big Data workflow development usually involves parts that are executed on Hadoop and parts that are executed or at least interact with resources outside of Hadoop. So, a unified configuration strategy will help developers when they move between different parts of the workflow. The basic configuration used across all Hadoop components is based on Spring and therefore similar whether working on a Hive job or an FTP file transfer job.
Q4. How does Spring for Apache Hadoop relate to the Spring Data project, and in general to the overall Spring ecosystem of projects?
Thomas Risberg: Spring for Apache Hadoop is part of the Spring Data umbrella project, but not part of the “release train” that most other Spring Data projects are part of. The reason is that the coupling is not very tight with other Spring Data projects. Spring for Apache Hadoop doesn’t directly use other Spring Data components although anyone using Spring for Apache Hadoop can use the Spring Data MongoDB project when exporting data from HDFS to MongoDB.
Q5. What about the integration with other software systems that are not part of the Spring ecosystem?
Thomas Risberg: In terms of Hadoop we have integration with Hive, Pig and HBase. We also use features from projects outside of the Apache Hadoop family. One example is Kite SDK which is a project that started out at Cloudera but is now a separate project that can be used with any Hadoop distribution. Other examples would be a JSON library like Jackson etc. The whole Spring IO platform uses 689 third party libraries so managing all of this is crucial for anyone using Spring. That is the main motivating factor behind the new Spring IO platform that provides a unified set of dependency versions across all Spring projects.
Q6. Could you give us some detail on how you handle big data ingest/export: e.g. from enterprise databases into Hadoop and vice versa? How is this different than conventional ETL?
Thomas Risberg: We rely on Spring Batch functionality for this task, so in case HDFS ingest isn’t different than loading data into any other data store. It’s simply a different batch writer. Spring Batch is a proven technology that is the bases for JSR-352 and is now certified as a JSR-352 compliant implementation. We support import/export with most relational databases that have a JDBC driver and also with many NoSQL stores that have Spring Data support like MongoDB, Cassandra, Couchbase or Redis.
Q7. What is the main contribution of Spring Data Hadoop to the Hadoop workflow and security?
Thomas Risberg: Spring for Apache Hadoop allows the developer to treat Hadoop workloads the same way as they would approach any workflow problem. Just because Hadoop is involved doesn’t have to mean that you need to use new and different tools from what you are used to. In terms of security we use what Hadoop itself provides and haven’t so far attempted to integrate that with Spring Security.
Q8. Do you also offer tools for analyzing Big Data? If yes, which ones?
Thomas Risberg: Spring XD provides integration with PMML analytics via a plug-in module. That module integrates with the JPMML-Evaluator library that provides support for a wide range of model types and is interoperable with models exported from R, Rattle, KNIME, and RapidMiner. Pivotal also provides MADLib, developed in collaboration with researchers at UC Berkeley and a growing world wide user community. This library is typically used with Pivotal’s Greenplum database or HAWQ which is the SQL engine that is part of Pivotal’s Hadoop distribution.
Q9. In which situations Spring Data Hadoop can add value, and in which situations would it be a poor choice?
Thomas Risberg: It definitely adds a lot of value if you are already using Spring in your workflow and just want to add some Hadoop functionality. It also makes sense if you are using Java and would like to take advantage of Spring’s dependency injection approach when developing your enterprise applications. It would make less sense for an organization that is not using Java as their development language or someone that already have a working solution using other tools that they are happy with.
Q10 Who is currently using Spring Data Hadoop and for which projects/business problems?
Thomas Risberg: I can’t name names, but Spring for Apache Hadoop together with Spring XD is used by many large organizations for developing new big data apps for stream processing and using HDFS for storage. Industries include telecommunications, equipment manufacturing, retail and finance. I’ve mentioned Spring XD and Spring for Apache Hadoop is a key component of this project. Spring XD is Pivotal’s new Spring project providing a unified, distributed, and extensible system for data ingestion, real time analytics, batch processing, and data export. The Spring XD project’s goal is to simplify the development of big data applications.
Thomas Risberg, Software Engineer focusing on Big Data, Pivotal, New Hampshire, USA
My current focus is on the “Spring XD”, “Spring for Apache Hadoop” and “Spring Data JDBC Extensions” projects. I’m a co-author of “Spring Data, Modern Data Access for Enterprise Java” published by O’Reilly Media in 2013 and “Professional Java Development with the Spring Framework” published by Wiley in 2005.
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“You need a team of dedicated data scientists to develop and tune the core intellectual property–statistical, predictive, and other analytic models–that drive your Big Data applications. You don’t often think of data scientists as “programmers,” per se, but they are the pivotal application developers in the age of Big Data.”–James Kobielus
Managing the pitfalls and challenges of Big Data projects. On this topic I have interviewed James Kobielus, IBM Senior Program Director, Product Marketing, Big Data Analytics solutions.
Q1. Why run a Big Data project in the enterprise?
James Kobielus: Many Big Data projects are in support of customer relationship management (CRM) initiatives in marketing, customer service, sales, and brand monitoring. Justifying a Big Data project with a CRM focus involves identifying the following quantitative ROI:
• Volume-based value: The more comprehensive your 360-degree view of customers and the more historical data you have on them, the more insight you can extract from it all and, all things considered, the better decisions you can make in the process of acquiring, retaining, growing and managing those customer relationships.
• Velocity-based value: The more customer data you can ingest rapidly into your big-data platform and the more questions that a user can pose more rapidly against that data (via queries, reports, dashboards, etc.) within a given time period prior, the more likely you are to make the right decision at the right time to achieve your customer relationship management objectives.
• Variety-based value: The more varied customer data you have – from the CRM system, social media, call-center logs, etc. – the more nuanced portrait you have on customer profiles, desires and so on, hence the better-informed decisions you can make in engaging with them.
• Veracity-based value: The more consolidated, conformed, cleansed, consistent current the data you have on customers, the more likely you are to make the right decisions based on the most accurate data.
How can you attach a dollar value to any of this? It’s not difficult. Customer lifetime value (CLV) is a standard metric that you can calculate from big-data analytics’ impact on customer acquisition, onboarding, retention, upsell, cross-sell and other concrete bottom-line indicators, as well as from corresponding improvements in operational efficiency.
Q2. What are the business decisions that need to be made in order to successfully support a Big Data project in the enterprise?
James Kobielus: In order to successfully support a Big Data project in the enterprise, you have to make the infrastructure and applications production-ready in your operations.
Production-readiness means that your big-data investment is fit to realize its full operational potential. If you think “productionizing” can be done in a single step, such as by, say, introducing HDFS NameNode redundancy, then you need a cold slap of reality. Productionizing demands a lifecycle focus that encompasses all of your big-data platforms, not just a single one (e.g., Hadoop/HDFS), and addresses more than just a single requirement (e.g., ensuring a highly available distributed file system).
Productionizing involves jumping through a series of procedural hoops to ensure that your big-data investment can function as a reliable business asset. Here are several high-level considerations to keep in mind as you ready your big-data initiative for primetime deployment:
• Stakeholders: Have you aligned your big-data initiatives with stakeholder requirements? If stakeholders haven’t clearly specified their requirements or expectations for your big-data initiative, it’s not production-ready. The criteria of production-readiness must conform to what stakeholders require, and that depends greatly on the use cases and applications they have in mind for Big Data. Service-level agreements (SLAs) vary widely for Big Data deployed as an enterprise data warehouse (EDW), as opposed to an exploratory data-science sandbox, an unstructured information transformation tier, a queryable archive, or some other use. SLAs for performance, availability, security, governance, compliance, monitoring, auditing and so forth will depend on the particulars of each big-data application, and on how your enterprise prioritizes them by criticality.
• Stacks: Have you hardened your big-data technology stack – databases, middleware, applications, tools, etc. – to address the full range of SLAs associated with the chief use cases? If the big-data platform does not meet the availability, security and other robustness requirements expected of most enterprise infrastructure, it’s not production-ready. Ideally, all production-grade big-data platforms should benefit from a common set of enterprise management tools.
• Scalability: Have you architected your environment for modular scaling to keep pace with inexorable growth in data volumes, velocities and varieties? If you can’t provision, add, or reallocate new storage, compute and network capacity on the big-data platform in a fast, cost-effective, modular way to meet new requirements, the platform is not production-ready.
• Skillsets: Have you beefed up your organization’s big-data skillsets for maximum productivity? If your staff lacks the requisite database, integration and analytics skills and tools to support your big-data initiatives over their expected life, your platform is not production-ready. Don’t go deep on Big Data until your staff skills are upgraded.
• Seamless service: Have your re-engineered your data management and analytics IT processes for seamless support for disparate big-data initiatives? If you can’t provide trouble response, user training and other support functions in an efficient, reliable fashion that’s consistent with existing operations, your big-data platform is not production-ready.
To the extent that your enterprise already has a mature enterprise data warehousing (EDW) program in production, you should use that as the template for your big-data platform. There is absolutely no need to redefine “productionizing” for Big Data’s sake.
Q3. What are the most common problems and challenges encountered in Big Data projects?
James Kobielus: The most common problems and challenges in Big Data projects revolve around integrated lifecycle management (ILM).
ILM faces a new frontier when it comes to Big Data. The core challenges are threefold: the sheer unbounded size of Big Data, the ephemeral nature of much of the new data, and the difficulty of enforcing consistent quality as the data scales along any and all of the three Vs (volume, velocity, and variability). Comprehensive ILM has grown more difficult to ensure in Big Data environments, given rapid changes in the following areas:
• New Big Data platform: Big data is ushering a menagerie of new platforms (Hadoop, NoSQL, in-memory, and graph databases) into enterprise computing environments, alongside stalwarts such MPP RDBMS, columnar, and dimensional databases. The chance that your existing ILM tools work out of the box with all of these new platforms is slim. Also, to the extent that you’re doing Big Data in a public cloud, you may be required to use whatever ILM features — strong, weak, or middling — that may be native to the provider’s environment. To mitigate your risks in this heterogeneous new world and to maintain strong confidence in your core data, you’ll need to examine new Big Data platforms closely to ensure they have ILM features (data security, governance, archiving, retention) that are commensurate to the roles for which you plan to deploy them.
• New Big Data subject domains: Big data has not altered enterprise requirements for data governance hubs where you store and manage office systems of record (customers, finances, HR). This is the role of your established EDW, most of which run on traditional RDBMS-based data platforms and incorporate strong ILM. But these systems of record data domains may have very little presence on your newer Big Data platforms, many of which focus instead on handling fresh data from social, event, sensor, clickstream, geospatial, and other new sources. These new data domains are often “ephemeral” in the sense there may be no need to retain the bulk of the data in permanent systems of record.
• New Big Data scales: Big data does not mean that your new platforms support infinite volume, instantaneous velocity, or unbounded varieties. The sheer magnitudes of new data will make it impossible to store most of it anywhere, given the stubborn technological and economic constraints we all face. This reality will deepen Big Data managers’ focus on tweaking multitemperature storage management, archiving, and retention policies. As you scale your Big Data environment, you will need to ensure that ILM requirements can be supported within your current constraints of volume (storage capacity), velocity (bandwidth, processor, and memory speeds), and variety (metadata depth).
Q4. How best is to get started with a Big Data project?
James Kobielus: Scope the project well to deliver near-term business benefit. Using the nucleus project as the foundation for accelerating future Big Data projects. Recognize that the initial database technology you use in that initial project is just one of many storage layers that will need to play together in a hybridized, multi-tier Big Data architecture of your future.
In the larger evolutionary perspective, Big Data is evolving into a hybridized paradigm under which Hadoop, massively parallel processing (MPP) enterprise data warehouses (EDW), in-memory columnar, stream computing, NoSQL, document databases, and other approaches support extreme analytics in the cloud.
Hybrid architectures address the heterogeneous reality of Big Data environments and respond to the need to incorporate both established and new analytic database approaches into a common architecture. The fundamental principle of hybrid architectures is that each constituent Big Data platform is fit-for-purpose to the role for which it’s best suited. These Big Data deployment roles may include any or all of the following:
• Data acquisition
• Interactive exploration
In any role, a fit-for-purpose Big Data platform often supports specific data sources, workloads, applications, and users.
Hybrid is the future of Big Data because users increasingly realize that no single type of analytic platform is always best for all requirements. Also, platform churn—plus the heterogeneity it usually produces—will make hybrid architectures more common in Big Data deployments. The inexorable trend is toward hybrid environments that address the following enterprise Big Data imperatives:
• Extreme scalability and speed: The emerging hybrid Big Data platform will support scale-out, shared-nothing massively parallel processing, optimized appliances, optimized storage, dynamic query optimization, and mixed workload management.
• Extreme agility and elasticity: The hybrid Big Data environment will persist data in diverse physical and logical formats across a virtualized cloud of interconnected memory and disk that can be elastically scaled up and out at a moment’s notice.
• Extreme affordability and manageability: The hybrid environment will incorporate flexible packaging/pricing, including licensed software, modular appliances, and subscription-based cloud approaches.
Hybrid deployments are already widespread in many real-world Big Data deployments. The most typical are the three-tier—also called “hub-and-spoke”—architectures. These environments may have, for example, Hadoop (e.g., IBM InfoSphere BigInsights) in the data acquisition, collection, staging, preprocessing, and transformation layer; relational-based MPP EDWs (e.g., IBM PureData System for Analytics) in the hub/governance layer; and in-memory databases (e.g., IBM Cognos TM1) in the access and interaction layer.
The complexity of hybrid architectures depends on range of sources, workloads, and applications you’re trying to support. In the back-end staging tier, you might need different preprocessing clusters for each of the disparate sources: structured, semi-structured, and unstructured. In the hub tier, you may need disparate clusters configured with different underlying data platforms—RDBMS, stream computing, HDFS, HBase, Cassandra, NoSQL, and so on—-and corresponding metadata, governance, and in-database execution components. And in the front-end access tier, you might require various combinations of in-memory, columnar, OLAP, dimensionless, and other database technologies to deliver the requisite performance on diverse analytic applications, ranging from operational BI to advanced analytics and complex event processing.
Ensuring that hybrid Big Data architectures stay cost-effective demands the following multipronged approach to optimization of distributed storage:
• Apply fit-for-purpose databases to particular Big Data use cases: Hybrid architectures spring from the principle that no single data storage, persistence, or structuring approach is optimal for all deployment roles and workloads. For example, no matter how well-designed the dimensional data model is within an OLAP environment, users eventually outgrow these constraints and demand more flexible decision support. Other database architectures—such as columnar, in-memory, key-value, graph, and inverted indexing—may be more appropriate for such applications, but not generic enough to address other broader deployment roles.
• Align data models with underlying structures and applications: Hybrid architectures leverage the principle that no fixed Big Data modeling approach—physical and logical—can do justice to the ever-shifting mix of queries, loads, and other operations. As you implement hybrid Big Data architectures, make sure you adopt tools that let you focus on logical data models, while the infrastructure automatically reconfigures the underlying Big Data physical data models, schemas, joins, partitions, indexes, and other artifacts for optimal query and data load performance.
• Intelligently compress and manage the data: Hybrid architectures should allow you to apply intelligent compression to Big Data sets to reduce their footprint and make optimal use of storage resources. Also, some physical data models are more inherently compact than others (e.g., tokenized and columnar storage are more efficient than row-based storage), just as some logical data models are more storage-efficient (e.g., third-normal-form relational is typically more compact than large denormalized tables stored in a dimensional star schema).
Q5. What kind of expertise do you need to run a Big Data project in the enterprise?
James Kobielus: Data-driven organizations succeed when all personnel—both technical and business—have a common understanding of the core big-data best skills, tools and practices. You need all the skills of data management, integration, modeling, and so forth that you already have running your data marts, warehouses, OLAP cubes, and the like.
Just as important, you need a team of dedicated data scientists to develop and tune the core intellectual property–statistical, predictive, and other analytic models–that drive your Big Data applications. You don’t often think of data scientists as “programmers,” per se, but they are the pivotal application developers in the age of Big Data.
The key practical difference between data scientists and other programmers—including those who develop orchestration logic—is that the former specifies logic grounded in non-deterministic patterns (i.e., statistical models derived from propensities revealed inductively from historical data), whereas the latter specifies logic whose basis is predetermined (i.e., if/then/else, case-based and other rules, procedural and/or declarative, that were deduced from functional analysis of some problem domain).
The practical distinctions between data scientists and other programmers have always been a bit fuzzy, and they’re growing even blurrier over time. For starters, even a cursory glance at programming paradigms shows that core analytic functions—data handling and calculation—have always been the heart of programming. For another, many business applications leverage statistical analyses and other data-science models to drive transactional and other functions.
Furthermore, data scientists and other developers use a common set of programming languages. Of course, data scientists differ from most other types of programmers in various ways that go beyond the deterministic vs. non-deterministic logic distinction mentioned above:
• Data scientists have adopted analytic domain-specific languages such as R, SAS, SPSS and Matlab.
• Data scientists specialize in business problems that are best addressed with statistical analysis.
• Data scientists are often more aligned with specific business-application domains—such as marketing campaign optimization and financial risk mitigation—than the traditional programmer.
These distinctions primarily apply to what you might call the “classic” data scientist, such as multivariate statistical analysts and data mining professionals. But the notion of a “classic” data scientist might be rapidly fading away in the big-data era as more traditional programmers need some grounding in statistical modeling in order to do their jobs effectively—or, at the very least, need to collaborate productively with statistical modelers.
Q6. How do you select the “right” software and hardware for a Big Data project?
James Kobielus: It’s best to choose the right appliance–a pre-optimized, pre-configured hardware/software appliance–for the specific workloads and applications of your Big Data project. At the same time, you should make sure that the chosen appliances can figure into the eventual cloud architecture toward which your Big Data infrastructure is likely to evolve.
An appliance is a workload-optimized system. Its hardware/software nodes are the key building block for every Big Data cloud. In other words, appliances, also known as expert integrated systems, are the bedrock of all three “Vs” of the Big Data universe, regardless of whether your specific high-level topology is centralized, hub-and-spoke, federated or some other configuration, and regardless of whether you’ve deployed all of these appliance nodes on premises or are outsourcing some or all of it to a cloud/SaaS provider.
Within the coming 2-3 years, expert integrated systems will become a dominant approach for enterprises to put Hadoop and other emerging Big Data approaches into production. Already, appliances are the principal approach in the core Big Data platform market: enterprise data warehousing solutions that implement massively parallel processing, such as those powered by IBM PureData Systems for Analytics..
The core categories of workloads that user need their optimized Big Data appliances to support within cloud environments are as follows:
• Big-data storage: A Big Data appliance can be core building block in a enterprise data storage architecture. Chief uses may be for archiving, governance and replication, as well as for discovering, acquiring, aggregating and governing multistructured content. The appliance should provide the modularity, scalability and efficiency of high-performance applications for these key data consolidation functions. Typically, it would support these functions through integration with a high-capacity storage area network architecture such as IBM provides.
• Big-data processing: A Big Data appliance should support massively parallel execution of advanced data processing, manipulation, analysis and access functions. It should support the full range of advanced analytics, as well as some functions traditionally associated with EDWs, BI and OLAP. It should have all the metadata, models and other services needed to handle such core analytics functions as query, calculation, data loading and data integration. And it should handle a subset of these functions and interface through connectors to analytic platforms such as IBM PureData Systems.
• Big-data development: A Big Data appliance should support Big Data modeling, mining, exploration and analysis. The appliance should provide a scalable “sandbox” with tools that allow data scientists, predictive modelers and business analysts to interactively and collaboratively explore rich information sets. It should incorporate a high-performance analytic runtime platform where these teams can aggregate and prepare data sets, tweak segmentations and decision trees, and iterate through statistical models as they look for deep statistical patterns. It should furnish data scientists with massively parallel CPU, memory, storage and I/O capacity for tackling analytics workloads of growing complexity. And it should enable elastic scaling of sandboxes from traditional statistical analysis, data mining and predictive modeling, into new frontiers of Hadoop/MapReduce, R, geospatial, matrix manipulation, natural language processing, sentiment analysis and other resource-intensive types of Big Data processing.
A big-data appliance should not be a stand-alone server, but, instead, a repeatable, modular building block that, when deployed in larger cloud configurations, can be rapidly optimized to new workloads as they come online. Many appliances will be configured to support mixes of two or all three of these types of workloads within specific cloud nodes or specific clusters. Some will handle low latency and batch jobs with equal agility in your cloud. And still others will be entirely specialized to a particular function that they perform with lightning speed and elastic scalability. The best appliances, like IBM Netezza, facilitate flexible re-optimization by streamlining the myriad deployment, configuration tuning tasks across larger, more complex deployments.
You may not be able to forecast with fine-grained precision the mix of workloads you’ll need to run on your big-data cloud two years from next Tuesday. But investing in the right family of big-data appliance building blocks should give you confidence that, when the day comes, you’ll have the foundation in place to provision resources rapidly and efficiently.
Q7. Is Hadoop replacing the role of OLAP (online analytical processing) in preparing data to answer specific questions?
James Kobielus: No. Hadoop is powering unstructured ETL, queryable archiving, data-science exploratory sandboxing, and other use cases. OLAP–in terms of traditional cubing–remains key to front-end query acceleration in decision support applications and data marts. In support of those front-end applicatioins, OLAP is facing competition from other approaches, especially in-memory, columnar databases (such as the BLU Acceleration feature of IBM DB2 10.5).
Q8. Could you give some examples of successful Big Data projects?
James Kobielus: Examples are here.
James Kobielus is IBM Senior Program Director, Product Marketing, Big Data Analytics solutions. He is an industry veteran, a popular speaker and social media participant, and a thought leader in big data, Hadoop, enterprise data warehousing, advanced analytics, business intelligence, data management, and next best action technologies.
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“As the database gets used, shards can grow at an uneven rate and one shard might carry a majority of the load. MongoDB corrects this by balancing shards, but because of MongoDB’s lack of concurrency this operation can stall the database unacceptably.”–John Partridge.
I have interviewed John Partridge, President & CEO of Tokutek, Inc.
Q1. Tokutek recently announced to have eliminated performance issues of MongoDB sharding. What was the problem?
John Partridge: The problem occurs after a shard is created. As the database gets used, shards can grow at an uneven rate and one shard might carry a majority of the load. MongoDB corrects this by balancing shards, but because of MongoDB’s lack of concurrency this operation can stall the database unacceptably (see the benchmark).
Q2. For what kind of application users of MongoDB experienced these bottlenecks?
John Partridge: Users who need to scale out, and rely on sharding to do so.
Q3. What is the solution you propose to this problem?
Q4. How TokuMX v1.4 is able to allow shards to be balanced and added without disruption for a NoSQL solution that scales up and scales out?
John Partridge: TokuMX replaces the B-tree indexing used in MongoDB with patented Fractal Tree indexing, which allows for significantly better concurrency (among other things). Because of the improved concurrency, data can be copied, then deleted, from one shard to another without unnecessary locking.
Q5. What is the difference in performance of your solution with respect to the basic MongoDB? What “basic” MongoDB do you use for this comparison?
John Partridge: “Basic” MongoDB is the distro that you get from MongoDB (10gen). We typically see 20x performance improvements but as you might imagine, it depends on the application. Because TokuMX offers document-level locking rather than the database-level locking, TokuMX shines when there are significant reads *and* writes.
Q6. How do you compare TokuMX with other distribution of MongoDB, such as the one of 10gen (now MongoDB)?
John Partridge: There are three major differences: 20x performance improvement, 90% smaller database size (we compress the data), and support for ACID transactions. Look at the bottom of http://www.tokutek.com/products/tokumx-for-mongodb/ for more information on each of these benefits.
Mr. Partridge brings over twenty years of experience in the software industry as a developer, investor, and entrepreneur. He joins Tokutek from StreamBase Systems which John co-founded with database pioneer Dr. Michael Stonebraker. He started his career as a software developer at Microsoft Corporation where he co-authored Excel v1.0. He later worked as a venture capitalist at Accel Partners and the Summit Accelerator Fund where he specialized in investing in early stage internet infrastructure and enterprise software companies. John holds an A.B. in Applied Mathematics / Computer Science from Harvard University and an MBA from the Stanford University Graduate School of Business.
– TokuMX vs. MongoDB : Sharding Balancer Performance Posted on February 16, 2014 by Tim Callaghan, Tokutek.
– What’s new in TokuMX 1.4, Part 4: Smaller, faster sharded clusters. Posted on February 20, 2014 by Leif Walsh, Tokutek.
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“So it is not even the volume of data that imputes political or economic value. Hence, it is clear that data has enormous political and economic value. Given the increasing digitization of our world it seems inevitable that our legal, economic, and political systems, amongst others, will ascribe to formal measures of value for data.” –Michael L. Brodie.
What is the other side of Big Data? What are the societal benefits, risks, and values of Big Data? These are difficult questions to answer.
On this topic, I have interviewed Dr. Michael L. Brodie, Research Scientist at MIT Computer Science and Artificial Intelligence Laboratory. Dr. Brodie has over 40 years experience in research and industrial practice.
Q1. You recently wrote  that “we are in the midst of two significant shifts – the shift to Big Data requiring new computational solutions, and the more profound shift in societal benefits, risks, and values”. Can you please elaborate on this?
Michael L. Brodie: The database world deals with data that is bounded, even if vast and growing beyond belief, and used for known, discrete models of our world most of which support a single version of truth. While Big Data expands the existing scale (volume, velocity, variety) it does far more as it takes us into a world that we experience in life but not in computing. I call the vision, the direction that Big Data is taking us, Computing Reality. A simple explanation is that in the database world, we work top-down with schemas that define how the data should behave. For example, Telecom billing systems are essentially all in an equivalence class of the same billing model and require that billing data conform. Billing databases have a single version of truth so that telecom bills have justifiable charges. Not so with Big Data.
If we impose a model or our biases on the data we may prelude the very value that we are trying to discover.
In Big Data worlds, as in life, there is not a single version of truth over the data but multiple perspectives each with a probability of being true or reasonable. We are probably not looking for one likely model but an ensemble of models each of which provides a different perspective and discloses some discoveries in the data that we otherwise would not have found.
So the one paradigm shift is from small data that involve discrete, bounded, top-down approaches to computing to big data that require bottom-up approaches that tend to be vague or probabilistic, unbounded, and provide support multiple perspectives. I call this latter approach Computing Reality, reflecting the vagueness and unboundedness of reality.
A second, related shift – from why to what – can be understood in terms of Scientific Discovery. The history of scientific and Western thought, starting before Aristotle and Plato, has matured into what we know today as the Scientific Method in which one makes observations about a phenomenon, e.g., sees some data, hypothesizes a model, and determines if the model makes sense over the observed data.
This process is What: What are the correlations in the data that might explain the phenomenon.
A reasonable model over the data leads to Why: the Holy Grail of Science – causation – Why does the phenomenon occur.
For over 2,000 years a little What has guided Why – Scientific Discovery through empiricism.
Big Data has the potential of turning scientific discovery on its ear. Big Data is leading to a shift from Why to What.
The value of Big Data and the emergence of Big Data analytics may shift the preponderance of scientific discovery to What, since it is so much cheaper that Why – clinical studies that take vast resources and years of careful work. Here is the challenge. Why – causation – cannot be deduced from What. It is not clear that Big Data practitioners understand the tenuous link between What and Why. Massive Big data blunders [1, 2] suggest that this is the case.
My research into Computing Reality explores this link with the hopes of providing guidance for Big Data tools and techniques. And even cooler than that to accelerate Scientific Discovery by adding mechanisms and metrics of veracity to Big Data and its symbiosis with empericism
Q2. You also wrote  that with Big Data “more than ever before, technology is far ahead of the law”. What do you mean with this?
Michael L. Brodie: The Forth Amendment of the United States Constitution was tested many times by technology including when electronic techniques could be used to determine activities inside a citizen’s home. When the constitution was written in 1787 electronic surveillance could never have been anticipated.
Today, the laws of search and seizure, based on the Fourth Amendment, permit those with a warrant to acquire all of your electronic devices so the government can examine everything on those devices although it appears that the intent of the law was to permit search and seizure of evidence relative to the suspected offence. That is, the current laws were perfectly rational when written; however, technology has so changed the world we live in that the law, interpreted simply allows the government to look at your entire digital life, which for many of us is much of our lives thus minimizing or eliminating the protections of the Fourth Amendment. The simple matter is that technology will always be ahead of the law.
So we must constantly balance current and unforeseen consequences of technology advance on our lives and societies.
Since time immemorial, and as observed by Benjamin Franklin, we must always judiciously balance freedom and security; you can’t have both. Technology more than many domains push this balance.
Q3. John Podesta, Obama’s Counselor and study lead, asked the following question during a workshop: „Does our legal privacy framework support and balance safety and freedom?“ What is your personal view on this especially related to the ongoing discussion on an open and free Internet and Big Data?
Michael L. Brodie: What a great question, worth of serious pursuit, more than I will pursue here. A fundamental part of your question is of a free and open Internet. While it is debatable as to whether computing or the Internet has created economic growth and increased productivity, it is fair to say that our economies have become so dependent on computing and that Balkanizing the Internet, as exemplified recently by Turkey, China, Brasil, and even Switzerland, will surely cause major economic disruption.
Not only does a significant portion of our existing economy ride on an currently open and free Internet, that platform has been and will continue to be a fountain of innovation and potential economic growth, and, ideally, increased productivity; not to mention the daily lives of billions of people on the planet. As we have seen in Tunisia, Egypt, North Korea, China, Syria, and other constrained countries, an open and free Internet, e.g., Twitter, is becoming a means for democratic expression and constraint on totalitarian behaviour. Much is at stake to maintain an open and free Internet.
This should encourage a robust debate of the various Internet Bill of Rights currently on offer. Clearly the Snowden-NSA incidents and the resulting events in the White House, the Supreme Court, and the US Congress clearly indicate that our legal privacy framework is inadequate. The more interesting question is what changes are required to permit a balance of freedom and safety. Such a framework should result from a robust, informed public debate on the issues. Hopefully these discussions will start in earnest. The workshop is an example of the White House’s commitment to such a discussion.
Q4. What would be the discussion on an open and free Internet, while balancing safety with freedom, if Edward Snowden had not disclosed the NSA surveillance?
Michael L. Brodie: What great questions with profound implications, clearly beyond my skills, but fun to poke at. Let me add to the question: Is Snowden a Whistle Blower or terrorist? Is he working to uphold the constitution or undermine it?
I happen to have had some direct experience on this issue. From April 2006 to January 2008 I served on the United States of America National Academies Committee on Technical and Privacy Dimensions of Information for Terrorism Prevention and other National Goals, co-chaired by Dr. Charles Vest, president of the National Academy of Engineering and Dr. William Perry, former US Secretary of Defense, that was commissioned by the Department of Homeland Security and the National Science Foundation.
The recent White House Investigation prompted by Snowden’s disclosures heavily cited the commission’s report .
The 21-month investigation by 20 experts chosen by the academy uncovered some aspects of what Snowden’s disclosures led to, it did not uncover the scope and scale of the NSA actions that emerged from Snowden’s disclosures. It is not until you discover the actions that you question the relevant laws or as the White House justifiably asked, the legal privacy framework to support and balance safety and freedom.
As I said in the piece that you reference the White House and Snowden are asking exactly the same questions. Snowden has said that he saw it as his obligation to do what he did given his oath to uphold the constitution. Hence, such a discussion could emerge without Snowden in the next decade, but it would not have emerged at the moment without his actions.
Would that it had emerged in 2006 or as a consequence of the many other similarly intended investigations.
It seems to me that Snowden blew the whistle on NSA.
Q5. De facto, the Internet is becoming a new battlefield among different political and economic systems in the world. What is the political and economic value of data?
Michael L. Brodie: Again a grand question for my betters. This is another profound question that I am not skilled to answer. But why let that stop me?
Our economic system is based on commodities, goods and services, with almost no means of attributing economic value to data. Indirectly, data is valued at inconceivably high values according to many Internet company acquisitions, especially Facebook’s recent $16 Billion acquisition of Whatsapp that appears to be acquiring people and their data by the network effect.
How do you ascribe value to data? Who owns data? Does it age and does time reduce or raise its value? If it has economic value, then what legal jurisdiction governs data? What is the political value of data? For one example look at Europe’s solicitation of business away from the United States based on data, data ownership, and data governance.
Another example is that President Lyndon Johnson achieved the US Civil Rights Bill because of data – he knew where all the bodies were buried. What is the value of data there?
So it is not even the volume of data that imputes political or economic value. Hence, it is clear that data has enormous political and economic value. Given the increasing digitization of our world it seems inevitable that our legal, economic, and political systems, amongst others, will ascribe to formal measures of value for data.
Q6. There has been a claim that “Big data” has rendered obsolete the current approach to protecting privacy and civil liberties . Is this really so?
Michael L. Brodie: Without question expanding beyond bounded, discrete, top-down models of the world, to a vastly larger, more complex digital version of the world, requires a reevaluation of previous approaches to computing problems, including privacy and civil liberties. The quote is from Craig Mundie  who makes the observation for a policy and strategy point of view. A recent report on machine learning and curly fries claims that organizations, e.g., marketing, can create complete profiles of individuals without their permission and presumably use it in many ways, e.g., refuse providing a loan? Does that threaten privacy and civil liberties?
While I quoted Mundie concerning civil liberties, my knowledge is in computing and databases. My reference concerns the fact that current solutions will simply not scale to the world of Big Data and Computing Reality. It seems a safe statement since Butler Lampson and Mike Stonebraker have both said the same thing. Simply stated, we cannot anticipate every attack, what combination of data accesses could be used to deduce private information. A famous case is to use Netflix movie selection data to identify private patient information from anonymized Medicare data. So while you may do a top-down job applying existing protection mechanisms, your only hope is to detect violations and stop further such attacks, as has been claimed for Heartbleed.
As Butler Lampson said 
“It’s time to change the way we think about computer security: instead of trying to prevent security breaches, we should focus on dealing with them after they happen.
Today computer security depends on access control, and it’s been a failure. Real world security, by contrast, is mainly retroactive: the reason burglars don’t break into my house is that they are afraid of going to jail, and the financial system is secure mainly because almost any transaction can be undone.
There are many ways to make security retroactive: • Track down and punish offenders. • Selectively undo data corruption caused by malware. Require applications and online services to respect people’s ownership of their personal data.
Access control is still needed, but it can be much more coarse-grained, and therefore both more reliable and less intrusive. Authentication and auditing are the most important features. Retroactive security will not be perfect, but perfect security is not to be had, and it will be much better than what we have now.”
 Protecting Individual Privacy in the Struggle Against Terrorism: A Framework for Program Assessment, Committee on Technical and Privacy Dimensions of Information for Terrorism Prevention and Other National Goals, National Research Council, Washington, D.C. 2008. ISBN-10: 0-309-12488-3 ISBN-13: 978-0-309-12488-1
 John Podesta, White House Counselor, White House-MIT Big Data Privacy Workshop: Advancing the State of the Art in Technology and Practice, March 4, 2014, MIT, Cambridge, MA http://web.mit.edu/bigdata-priv/agenda.html
 White House-MIT Big Data Privacy Workshop A Personal View, Dr. Michael L. Brodie , Computer Science and Artificial Intelligence Laboratory, MIT , March 24, 2014 http://www.odbms.org/2014/04/white-house-mit-big-data-privacy-workshop/
Dr. Michael L. Brodie
Dr. Brodie has over 40 years experience in research and industrial practice in databases, distributed systems, integration, artificial intelligence, and multi-disciplinary problem solving. He is concerned with the Big Picture aspects of information ecosystems including business, economic, social, application, and technical. Dr. Brodie is a Research Scientist, MIT Computer Science and Artificial Intelligence Laboratory; advises startups; serves on Advisory Boards of national and international research organizations; and is an adjunct professor at the National University of Ireland, Galway. For over 20 years he served as Chief Scientist of IT, Verizon, a Fortune 20 company, responsible for advanced technologies, architectures, and methodologies for Information Technology strategies and for guiding industrial scale deployments of emergent technologies, most recently Cloud Computing and Big Data and start ups Jisto.com and data-tamer.com. He has served on several National Academy of Science committees.
Dr. Brodie holds a PhD in Databases from the University of Toronto and a Doctor of Science (honoris causa) from the National University of Ireland.
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“SciDB is both a data store and a massively parallel compute engine for numerical processing. The inclusion of this computational platform is what makes us the first “computational database”, not just a SQL-style decision support DBMS. Hence, we need a new moniker to describe this class of interactions. We settled on computational databases, but if your readers have a better suggestion, we are all ears!”
–Mike Stonebraker, Paul Brown.
On the SciDB array database, I have interviewed Mike Stonebraker, MIT Professor and Paradigm4 co-founder and CTO, and Paul Brown, Paradigm4 Chief Architect.
Q1: What is SciDB and why did you create it?
Mike Stonebraker, Paul Brown: SciDB is an open source array database with scalable, built-in complex analytics, programmable from R and Python. The requirements for SciDB emerged from discussions between academic database researchers—Mike Stonebraker and Dave DeWitt— and scientists at the first Extremely Large Databases conference (XLDB) at SLAC in 2007 about coping with the peta-scale data from the forthcoming LSST telescope.
Recognizing that commercial and industrial users were about to face the same challenges as scientists, Mike Stonebraker founded Paradigm4 in 2010 to make the ideas explored in early prototypes available as a commercial-quality software product. Paradigm4 develops and supports both a free, open-source Community Edition (scidb.org/forum) and an Enterprise Edition with additional features (paradigm4.com).
Q2. With the rise of Big Data analytics, is the convergence of analytic needs between science and industry really happening?
Mike Stonebraker, Paul Brown: There is a “sea change” occurring as companies move from Business Intelligence (think SQL analytics) to Complex Analytics (think predictive modelling, clustering, correlation, principal components analysis, graph analysis, etc.). Obviously science folks have been doing complex analytics on big data all along.
Another force driving this sea change is all the machine-generated data produced by cell phones, genomic sequencers, and by devices on the Industrial Internet and the Internet of Things. Here too science folks have been working with big data from sensors, instruments, telescopes and satellites all along. So it is quite natural that a scalable computational database like SciDB that serves the science world is a good fit for the emerging needs of commercial and industrial users.
There will be a convergence of the two markets as many more companies aspire to develop innovative products and services using complex analytics on big and diverse data. In the forefront are companies doing electronic trading on Wall Street; insurance companies developing new pricing models using telematics data; pharma and biotech companies analyzing genomics and clinical data; and manufacturing companies building predictive models to anticipate repairs on expensive machinery. We expect everybody will move to this new paradigm over time. After all, a predictive model integrating diverse data is much more useful than a chart of numbers about past behavior.
Q3. What are the typical challenges posed by scientific analytics?
Mike Stonebraker, Paul Brown: We asked a lot of working scientists the same question, and published a paper in the IEEE Computing Science & Engineering summarizing their answers (*see citation below). In a nutshell, there are 4 primary issues.
1. Scale. Science has always been intensely “data driven”. With the ever-increasing massive data-generating capabilities of scientific instruments, sensors, and computer simulations, the average scientist is overwhelmed with data and needs data management and analysis tools that can scale to meet his or her needs, now and in the future.
2. New Analytic Methods. Historically analysis tools have focused on business users, and have provided easy-to-use interfaces for submitting SQL aggregates to data warehouses. Such business intelligence (BI) tools are not useful to scientists, who universally want much more complex analyses, whether it be outlier detection, curve fitting, analysis of variance, predictive models or network analysis. Such “complex analytics” is defined on arrays in linear algebra, and requires a new generation of client-side tools and server side tools in DBMSs.
3. Provenance. One of the central requirements that scientists have is reproducibility. They need to be able to send their data to colleagues to rerun their experiments and produce the same answers. As such, it is crucial to keep prior versions of data in the face of updates, error correction, and the like. The right way to provide such provenance is through a no-overwrite DBMS; which allows time-travel back in time to when the experiment in question was performed.
4. Interactivity. Unlike business users who are often comfortable with batch reporting of information, scientific users are invariably exploring their data, asking “what if” questions and testing hypotheses. What they need in interactivity on very large data sets.
Q3. What are in your opinion the commonalities between scientific and industrial analytics?
Mike Stonebraker, Paul Brown: We would state the question in reverse “What are the differences between the two markets?” In our opinion, the two markets will converge quickly as commercial and industrial companies move to the analytic paradigms pervasive in the science marketplace.
Q4. How come in the past the database system software community has failed to build the kinds of systems that scientists needed for managing massive data sets?
Mike Stonebraker, Paul Brown: Mostly it’s because scientific problems represent a $0 billion market! However, the convergence of industrial requirements and science requirements means that science can “piggy back” on the commercial market and get their needs met.
Q5. SciDB is a scalable array database with native complex analytics. Why did you choose a data model based on multidimensional arrays?
Mike Stonebraker, Paul Brown: Our main motivation is that at scale, the complex analyses done by “post sea change” users are invariably about applying parallelized linear algebraic algorithms to arrays. Whether you are doing regression, singular value decomposition, finding eigenvectors, or doing operations on graphs, you are performing a sequence of matrix operations. Obviously, this is intuitive and natural in an array data model, whereas you have to recast tables into arrays if you begin with an RDBMS or keep data in files. Also, a native array implementation can be made much faster than a table-based system by directly implementing multi-dimensional clustering and doing selective replication of neighboring data items.
Our secondary motivation is that, just like mathematical matrices, geospatial data, time-series data, image data, and graph data are most naturally organized as arrays. By preserving the inherent ordering in the data, SciDB supports extremely fast selection (including vectors, planes, ‘hypercubes’), doing multi-dimensional windowed aggregates, and re-gridding it to change spatial or temporal resolution.
Q6. How do you manage in a nutshell scalability with high degrees of tolerance to failures?
Mike Stonebraker, Paul Brown: In a nutshell? Partitioning, and redundancy (k-replication).
First, SciDB splits each array’s attributes apart, just like any columnar system. Then we partition each array into rectilinear blocks we call “chunks”. Then we employ a variety of mapping functions that map an array’s chunks to SciDB instances. For each copy of an array we use a different mapping function to create copies of each chunk on different node of the cluster. If a node goes down, we figure out where there is a redundant copy of the data and move the computation there.
Q7. How do you handle data compression in SciDB?
Mike Stonebraker, Paul Brown: Use of compression in modern data stores is a very important topic. Minimizing storage while retaining information and supporting extremely rapid data access informs every level of SciDB’s design. For example, SciDB splits every array into single-attribute components. We compress a chunk’s worth of cell values for a specific attribute. At the lowest level, we compress attribute data using techniques like run-length encoding on data. In addition, our implementation has an abstraction for compression to support other compression algorithms.
Q8. Why supporting two query languages?
Mike Stonebraker, Paul Brown: Actually the primary interfaces we are promoting are R and Python as they are the languages of choice of data scientists, quants, bioinformaticians, and scientists. SciDB-R and SciDB-Py allow users to interactively query SciDB using R and Python. Data is persisted in SciDB. Math operators are overloaded so that complex analytical computations execute scalably in the database.
Early on we surveyed potential and existing SciDB users, and found there were two very different types. By and large, commercial users using RDMBSs said “make it look like SQL”. For those users we created AQL—array SQL. On the other hand, data scientists and programmers preferred R, Python, and functional languages. For the second class of users we created SciDB-R, SciDB-Py, and AFL—an array functional language.
All queries get compiled into a query plan, which is a sequence of algebraic operations. Essentially all relational versions of SQL do exactly the same thing. In SciDB, AFL, the array functional language, is the underlying language of algebraic operators. Hence, it is easy to surface and support AFL in addition to AQL, SciDB-R, and SciDB-Py, allowing us to satisfy the preferred mode of working for many classes of users.
Q9. You defined SciDB a computational database – not a data warehouse, not a business-intelligence database, and not a transactional database. Could you please elaborate more on this point?
Mike Stonebraker, Paul Brown: In our opinion, there are two mature markets for DBMSs: transactional DBMSs that are optimized for large numbers of users performing short write-oriented ACID transactions, and data warehouses, which strive for high performance on SQL aggregates and other read-oriented longer queries. The users of SciDB fit into neither category. They are universally doing more complex mathematical calculations than SQL aggregates on their data, and their DBMS interactions are typically longer read-oriented queries. SciDB is both a data store and a massively parallel compute engine for numerical processing. The inclusion of this computational platform is what makes us the first “computational database”, not just a SQL-style decision support DBMS. Hence, we need a new moniker to describe this class of interactions. We settled on computational databases, but if your readers have a better suggestion, we are all ears!
Q10. How does SciDB differ from analytical databases, such as for example HP Vertica, and in-memory analytics databases such as SAP HANA?
Mike Stonebraker, Paul Brown: Both are data warehouse products, optimized for warehouse workloads. SciDB serves a different class of users from these other systems. Our customers’ data are naturally represented as arrays that don’t fit neatly or efficiently into relational tables. Our users want more sophisticated analytics—more numerical, statistical, and graph analysis—and not so much SQL OLAP.
Q11. What about Teradata?
Mike Stonebraker, Paul Brown: Another data warehouse vendor. Plus, SciDB runs on commodity hardware clusters or in a cloud and not on a proprietary appliances or expensive servers.
Q12. Anything else you wish to add?
Mike Stonebraker, Paul Brown: SciDB is currently being used by commercial users for computational finance, bioinformatics and clinical informatics, satellite image analysis, and industrial analytics. The publicly accessible NIH NCBI One Thousand Genomes browser has been running on SciDB since the Fall of 2012.
Anyone can try out SciDB using an AMI or a VM available at scidb.org/forum.
Mike Stonebraker , CTO Paradigm4
Renowned database researcher, innovator, and entrepreneur: Berkeley, MIT, Postgres, Ingres, Illustra, Cohera, Streambase, Vertica, VoltDB, and now Paradigm4.
Paul Brown , Chief Architect Paradigm4
Premier database ‘plumber’ and researcher moving from the “I’s” (Ingres, Illustra, Informix, IBM) to a “P” (Paradigm4).
*Citation for IEEE paper
Stonebraker, M.; Brown, P.; Donghui Zhang; Becla, J., “SciDB: A Database Management System for Applications with Complex Analytics,” Computing in Science & Engineering , vol.15, no.3, pp.54,62, May-June 2013
doi: 10.1109/MCSE.2013.19, URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6461866&isnumber=6549993
– ODBMS.org: free resources related to Paradigm4
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“High volume and data driven businesses have led to new types of data emerging from the cloud, mobile devices, social media and sensor devices. For applications processing such data, traditional relational databases such as Oracle simply run out of steam.”–Robin Schumacher
The sixth interview in the “Big Data: three questions to “ series of interviews, is with Robin Schumacher, VP of Products at DataStax.
Q1. What is your current product offering?
Robin Schumacher: DataStax offers the first enterprise-class NoSQL platform for data-driven, real-time online applications. Our flagship product is DataStax Enterprise 4.0, built on Apache Cassandra. It is a complete big data platform with the full power of Cassandra offering a range of solutions including built in analytics, integrated search, an in-memory options, and the most comprehensive security feature set of any NoSQL database.
An integrated analytics component allows users to store and manage line of business application data and analyzes that same data within the platform. The analytics capability allows for comprehensive workload management and allows the user to run real time transactions and enterprise search workloads in a seamlessly integrated database.
Built in search offers robust full text search, faceted search, rich document handling and geospatial search.
Benefits include full workload management, continuous availability, real-time functionality and data protection.
Lastly, security runs through the entire platform to protect unauthorized access to guard sensitive data. Visual backup and restore processes make for retrieving lost data extremely easy.
DataStax OpsCenter, a simplified management solution, is included with DataStax Enterprise. This service makes it easy to manage Cassandra and DataStax Enterprise clusters by giving administrators, architects and developers a view of the system from a centralized dashboard. OpsCenter installs seamlessly and gives system operators the flexibility to monitor and manage the most complex workloads from any web browser.
Q2. Who are your current customers and how do they typically use your products?
Robin Schumacher: DataStax is the first viable alternative to Oracle and powers the online applications for 400+ customers and more than 20 of the Fortune 100. Our customer industries range from e-commerce to education to digital entertainment and the top use cases are the following:
1. Fraud detection
2. The Internet of Things
The most common baseline use for our product is to serve as an operational database management system for online applications that must scale to incredible levels and must remain online at all times.
Q3. What are the main new technical features you are currently working on and why?
Robin Schumacher: We recently added an in-memory option that enables companies to process data up to 100 times faster. This option excels in use cases that require fast write and read operations, and is particularly suited when data is overwritten frequently, but not actually deleted. DataStax Enterprise 4.0 is the first NoSQL database to combine this in memory option with Cassandra¹s always on architecture, linear scalability and datacenter support, delivering lightning performance that allows businesses to scale applications with zero downtime – particularly useful in financial services use cases or any application where performance is key.
High volume and data driven businesses have led to new types of data emerging from the cloud, mobile devices, social media and sensor devices. For applications processing such data, traditional relational databases such as Oracle simply run out of steam. DataStax Enterprise 4.0 offers a powerful, modern alternative to help build online applications that scale as the business grows. This in-memory capability equals faster performance, easy development, flexible performance management and seamless search:
Objects created in-memory optimize performance and deliver increased speed which enables businesses to deliver data to customers faster than ever before.
In-memory objects act as Cassandra tables so they are transparent to applications and developers have no learning curve to manage.Administrators can decide where to assign data, making performance optimization easier than ever.
Enhanced internal cluster communications deliver faster search operations help developers build applications more efficiently.
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“The real problem here is the word “silo.” To answer today’s data challenges requires a holistic approach. Your storage, network and compute need to work together.”–David Gorbet.
What are the challenges for modern data centers? On this topic I have interviewed David Gorbet, Vice President of Engineering at MarkLogic.
Q1. Data centers are evolving to meet the demands and complexities imposed by increasing business requirements. What are the main challenges?
David Gorbet: The biggest business challenge is the rapid pace of change in both available data and business requirements. It’s no longer acceptable to spend years designing a data application, or the infrastructure to run it. You have to be able to iterate on functionality quickly. This means that your applications need to be developed in a much more agile manner, but you also need to be able to reallocate your infrastructure dynamically to the most pressing needs. In the era of Big Data this problem is exacerbated. The increasing volume and complexity of data under management is stressing both existing technologies and IT budgets. It’s not just a matter of scale, although traditional “scale-up” technologies do become very expensive as data volumes grow. It’s also a matter of complexity of data. Today a lot of data has a mix of structured and unstructured components, and the traditional solution to this problem is to split the structured components into an RDBMS, and use a search technology for the unstructured components. This creates additional complexity in the infrastructure, as different technology stacks are required for what really should be components of the same data.
Traditional technologies for data management are not agile. You have to spend an inordinate amount of time designing schemas and planning indexing strategies, both of which require pretty-much full knowledge of the data and query patterns you need to provide the application value. This has to be done before you can even load data. On the infrastructure side, even if you’ve embraced cloud technologies like virtualization, it’s unlikely you’re able to make good use of them at the data layer. Most database technologies are not architected to allow elastic expansion or contraction of capacity or compute power, which makes it hard to achieve many of the benefits (and cost savings) of cloud technologies.
To solve these problems you need to start thinking differently about your data center strategy. You need to be thinking about a data-centered data center, versus today’s more application-centered model.
Q2. You talked about a “data-centered” data center? What is it? and what is the difference with respect to a classical Data-Warehouse?
David Gorbet: To understand what I mean by “data-centered” data center, you have to think about the alternative, which is more application-centered. Today, if you have data that’s useful, you build an application or put it in a data warehouse to unlock its value. These are database applications, so you need to build out a database to power them. This database needs a schema, and that schema is optimized for the application. To build this schema, you need to understand both the data you’ll be using, and the queries that the application requires.
So you have to know in advance everything the application is going to do before you can build anything. What’s more, you then have to ETL this data from wherever it lives into the application-specific database.
Now, if you want another application, you have to do the same thing. Pretty soon, you have hundreds of data stores with data duplicated all over the place. Actually, it’s not really duplicated, it’s data derived from other data, because as you ETL the data you change its form losing some of the context and combining what’s left with bits of data from other sources. That’s even worse than straight-up duplication because provenance is seldom retained through this process, so it’s really hard to tell where data came from and trace it back to its source. Now imagine that you have to correct some data.
Can you be sure that the correction flowed through to every downstream system? Or what if you have to delete data due to a privacy issue, or change security permissions on data? Even with “small data” this is complicated, but it’s much harder and costlier with high volumes of data.
A “data-centered” data center is one that is focused on the data, its use, and its governance through its lifecycle as the primary consideration. It’s architected to allow a single management and governance model, and to bring the applications to the data, rather than copying data to the applications. With the right technologies, you can build a data-centered data center that minimizes all the data duplication, gives you consistent data governance, enables flexibility both in application development over the data and in scaling up and down capacity to match demand, allowing you to manage your data securely and cost-effectively throughout its lifecycle.
Q3. Data center resources are typically stored in three silos: compute, storage and network: is this a problem?
David Gorbet: It depends on your technology choices. Some data management technologies require direct-attached storage (DAS), so obviously you can’t manage storage separately with that kind of technology. Others can make use of either DAS or shared storage like SAN or NAS.
With the right technology, it’s not necessarily a problem to have storage managed independently from compute.
The real problem here is the word “silo.” To answer today’s data challenges requires a holistic approach. Your storage, network and compute need to work together.
Your question could also apply to application architectures. Traditionally, applications are built in a three-tiered architecture, with a DBMS for data management, an application server for business logic, and a front-end client where the UI lives. There are very good reasons for this architecture, and I believe it’s likely to be the predominant model for years to come. But even though business logic is supposed to reside in the app server, every enterprise DBMS supports stored procedures, and these are commonly used to leverage compute power near the data for cases where it would be too slow and inefficient to move data to the middle tier. Increasingly, enterprise DBMSes also have sophisticated built-in functions (and in many cases user-defined functions) to make it easy to do things that are most efficiently done right where the data lives. Analytic aggregate calculations are a good example of this. Compute doesn’t just reside in the middle tier.
This is nothing new, so why am I bringing it up? Because as data volumes grow larger, the problem of moving data out of the DBMS to do something with it is going to get a lot worse. Consider for example the problem faced by the National Cancer Institute. The current model for institutions wanting to do research based on genomic data is to download a data set and analyze it. But by the end of 2014, the Cancer Genome Atlas is expected to have grown from less than 500 TB to 2.5 PB. Just downloading 2.5 PB, even over 10-gigabit network would take almost a month.
The solution? Bring more compute to the data. The implication? Twofold: First, methods for narrowing down data sets prior to acting on them are critical. This is why search technology is fast becoming a key feature of a next-generation DBMS. Search is the query language for unstructured data, and if you have complex data with a mix of structured and unstructured components, you need to be able to mix search and query seamlessly. Second, DBMS technologies need to become much more powerful so that they can execute sophisticated programs and computations efficiently where the data lives, scoped in real-time to a search that can narrow the input set down significantly. That’s the only way this stuff is going to get fast enough to happen in real-time. Another way of putting this is that the “M” in DBMS is going to increase in scope. It’s not enough just to store and retrieve data. Modern DBMS technology needs to be able to do complex, useful computations on it as well.
Q4. How do you build such a “data-centered” data center?
David Gorbet: First you need to change your mindset. Think about the data as the center of everything. Think about managing your data in one place, and bringing the application to the data by exposing data services off your DBMS. The implications for how you architect your systems are significant. Think service-oriented architectures and continuous deployment models.
Next, you need the right technology stack. One that can provide application functionality for transactions, search and discovery, analytics, and batch computation with a single governance and scale model. You need a storage system that gives great SLAs on high-value data and great TCO on lower-value data, without ETL. You need the ability to expand and contract compute power to serve the application needs in real time without downtime, and to run this infrastructure on premises or in the cloud.
You need the ability to manage data throughout its lifecycle, to take it offline for cost savings while leaving it available for batch analytics, and to bring it back online for real-time search, discovery or analytics within minutes if necessary. To power applications, you need the ability to create powerful, performant and secure data services and expose them right from where the data lives, providing the data in the format needed by your application on the fly.
We call this “schema on read.”
Of course all this has to be enterprise class, with high availability, disaster recovery, security, and all the enterprise functionality your data deserves, and it has to fit in your shrinking IT budget. Sounds impossible, but the technology exists today to make this happen.
Q5. For what kind of mission critical apps is such a “data-centered” data center useful?
David Gorbet: If you have a specific application that uses specific data, and you won’t need to incorporate new data sources to that application or use that data for another application, then you don’t need a data-centered data center. Unfortunately, I’m having a hard time thinking of such an application. Even the dull line of business apps don’t stand alone anymore. The data they create and maintain is sent to a data warehouse for analysis.
The new mindset is that all data is potentially valuable, and that isn’t just restricted to data created in-house.
More and more data comes from outside the organization, whether in the form of reference data, social media, linked data, sensor data, log data… the list is endless.
A data-centered data center strategy isn’t about a specific application or application type. It’s about the way you have to think about your data in this new era.
Q6. How Hadoop fits into this “data-centered” data center?
David Gorbet: Hadoop is a key enabling technology for the data-centered data center. HDFS is a great file system for storing loads of data cheaply.
I think of it as the new shared storage infrastructure for “big data.” Now HDFS isn’t fast, so if you need speed, you may need NAS, SAN, or even DAS or SSD. But if you have a lot of data, it’s going to be much cheaper to store it in HDFS than in traditional data center storage technologies. Hadoop MapReduce is a great technology for batch analytics. If you want to comb through a lot of data and do some pretty sophisticated stuff to it, this is a good way to do it. The downside to MapReduce is that it’s for batch jobs. It’s not real-time.
So Hadoop is an enabling technology for a data-centered data center, but it needs to be complemented with high-performance storage technologies for data that needs this kind of SLA, and more powerful analytic technologies for real-time search, discovery and analysis. Hadoop is not a DBMS, so you also need a DBMS with Hadoop to manage transactions, security, real-time query, etc.
Q7. What are the main challenges when designing an ETL strategy?
David Gorbet: ETL is hard to get right, but the biggest challenge is maintaining it. Every app has a v2, and usually this means new queries that require new data that needs a new schema and revised ETL. ETL also just fundamentally adds complexity to a solution.
It adds latency since many ETL jobs are designed to run in batches. It’s hard to track provenance of data through ETL, and it’s hard to apply data security and lifecycle management rules through ETL. This isn’t the fault of ETL or ETL tools.
It’s just that the model is fundamentally complex.
Q8. With Big Data analytics you don’t know in advance what data you’re going to need (or get in the future). What is the solution to this problem?
David Gorbet: This is a big problem for relational technologies, where you need to design a schema that can fit all your data up front.
The best approach here is to use a technology that does not require a predefined schema, and that allows you to store different entities with different schemas (or no schema) together in the same database and analyze them together.
A document database, which is a type of NoSQL database, is great for this, but be careful which one you choose because some NoSQL databases don’t do transactions and some don’t have the indexing capability you need to search and query the data effectively.
Another trend is to use Semantic Web technology. This involves modeling data as triples, which represent assertions with a subject, a predicate, and an object.
Like “This derivative (subject) is based on (predicate) this underlying instrument (object).”
It turns out you can model pretty much any data that way, and you can invent new relationships (predicates) on the fly as you need them.
No schema required. It’s also easy to relate data entities together, since triples are ideal for modeling relationships. The challenge with this approach is that there’s still quite a bit of thought required to figure out the best way to represent your data as triples. To really make it work, you need to define rules about what predicates you’re going to allow and what they mean so that data is modeled consistently.
Q9. What is the cost to analyze a terabyte of data?
David Gorbet: That depends on what technologies you’re using, and what SLAs are required on that data.
If you’re ingesting new data as you analyze, and you need to feed some of the results of the analysis back to the data in real time, for example if you’re analyzing risk on derivatives trades before confirming them, and executing business rules based on that, then you need fast disk, a fair amount of compute power, replicas of your data for HA failover, and additional replicas for DR. Including compute, this could cost you about $25,000/TB.
If your data is read-only and your analysis does not require high-availability, for example a compliance application to search those aforementioned derivatives transactions, you can probably use cheaper, more tightly packed storage and less powerful compute, and get by with about $4,000/TB. If you’re doing mostly batch analytics and can use HDFS as your storage, you can do this for as low as $1,500/TB.
This wide disparity in prices is exactly why you need a technology stack that can provide real-time capability for data that needs it, but can also provide great TCO for the data that doesn’t. There aren’t many technologies that can work across all these data tiers, which is why so many organizations have to ETL their data out of their transactional system to an analytic or archive system to get the cost savings they need. The best solution is to have a technology that can work across all these storage tiers and can manage migration of data through its lifecycle across these tiers seamlessly.
Again, this is achievable today with the right technology choices.
David Gorbet, Vice President, Engineering, MarkLogic.
David brings two decades of experience bringing to market some of the highest-volume applications and enterprise software in the world. David has shipped dozens of releases of business and consumer applications, server products and services ranging from open source to large-scale online services for businesses, and twice has helped start and grow billion-dollar software products.
Prior to MarkLogic, David helped pioneer Microsoft’s business online services strategy by founding and leading the SharePoint Online team. In addition to SharePoint Online, David has held a number of positions at Microsoft and elsewhere with a number of products, including Microsoft Office, Extricity B2Bi server software, and numerous incubation products.
David holds a Bachelor of Applied Science degree in Systems Design Engineering with an additional major in Psychology from the University of Waterloo, and an MBA from the University of Washington Foster School of Business.
– Got Loss? Get zOVN!
Authors: Daniel Crisan, Robert Birke, Gilles Cressier, Cyriel Minkenberg and Mitch Gusat. IBM Research – Zurich Research Laboratory.
Abstract: Datacenter networking is currently dominated by two major trends. One aims toward lossless, flat layer-2 fabrics based on Converged Enhanced Ethernet or InfiniBand, with ben- efits in efficiency and performance.
– F1: A Distributed SQL Database That Scales
Authors: Jeff Shute, Radek Vingralek, Eric Rollins, Stephan Ellner, Traian Stancescu, Bart Samwel, Mircea Oancea, John Cieslewicz, Himani Apte, Ben Handy, Kyle Littlefield, Ian Rae*. Google, Inc., *University of Wisconsin-Madison
Abstract: F1 is a distributed relational database system built at Google to support the AdWords business.
David Gorbet will be speaking at MarkLogic World in San Francisco from April 7-10, 2014.
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“Despite the obvious shared word ‘transaction’ and the canonical example of a database transaction which modifies multiple bank accounts, I don’t think that database transactions are particularly relevant to financial applications.”–Dave Rosenthal.
On SQL and NoSQL, I have interviewed Dave Rosenthal CEO of FoundationDB.
Q1. What are the suggested criteria for users when they need to choose between durability for lower latency, higher throughput and write availability?
Dave Rosenthal: There is a tradeoff in available between commit latency and durability–especially in distributed databases. At one extreme a database client can just report success immediately (without even talking to the database server) and buffer the writes in the background. Obviously, that hides latency well, but you could lose a suffix of transactions. At the other extreme, you can replicate writes across multiple machines, fsync them on each of the machines, and only then report success to the client.
FoundationDB is optimized to provide good performance in its default setting, which is the safest end of that tradeoff.
Usually, if you want some reasonable amount of durability guarantee, you are talking about a commit latency of small constant factor times the network latency. So, the real latency issues come with databases spanning multiple data centers. In that case FoundationDB users are able to choose whether or not they want durability guarantees in all data centers before commit (increasing commitment latencies), which is our default setting, or whether they would like to relax durability guarantees by returning a commit when the data is fsync’d to disk in just one datacenter.
All that said, in general, we think that the application is usually a more appropriate place to try to hide latency than the database.
Q2. Justin Sheehy of Basho in an interview said  “I would most certainly include updates to my bank account as applications for which eventual consistency is a good design choice. In fact, bankers have understood and used eventual consistency for far longer than there have been computers in the modern sense”. What is your opinion on this?
Dave Rosenthal: Yes, we totally agree with Justin. Despite the obvious shared word ‘transaction’ and the canonical example of a database transaction which modifies multiple bank accounts, I don’t think that database transactions are particularly relevant to financial applications. In fact, true ACID transactions are way more broadly important than that. They give you the ability to build abstractions and systems that you can provide guarantees about.
As Michael Cahill says in his thesis which became the SIGMOD paper of the year: “Serializable isolation enables the development of a complex system by composing modules, after verifying that each module maintains consistency in isolation.” It’s this incredibly important ability to compose that makes a system with transactions special.
Q3. FoundationDB claim to provide full ACID transactions. How do you do that?
Dave Rosenthal: In the same basic way as many other transactional databases do. We use a few strategies that tend to work well in distributed system such as optimistic concurrency and MVCC. We also, of course, have had to solve some of the fundamental challenges associated with distributed systems and all of the crazy things that can happen in them. Honestly, it’s not very hard to build a distributed transactional database. The hard part is making it work gracefully through failure scenarios and to run fast.
Q4. Is this similar to Oracle NoSQL?
Dave Rosenthal: Not really. Both Oracle NoSQL and FoundationDB provide an automatically-partitioned key-value store with fault tolerance. Both also have a concept of ordering keys (for efficient range operations) though Oracle NoSQL only provides ordering “within a Major Key set”. So, those are the similarities, but there are a bunch of other NoSQL systems with all those properties. The huge difference is that FoundationDB provides for ACID transactions over arbitrary keys and ranges, while Oracle NoSQL does not.
Q5. How would you compare your product offering with respect to NoSQL data stores, such as CouchDB, MongoDB, Cassandra and Riak, and NewSQL such as NuoDB and VoltDB?
Dave Rosenthal: The most obvious response for the NoSQL data stores would be “we have ACID transactions, they don’t”, but the more important difference is in philosophy and strategy.
Each of those products expose a single data model and interface. Maybe two. We are pursuing a fundamentally different strategy.
We are building a storage substrate that can be adapted, via layers, to provide a variety of data models, APIs, and true flexibility.
We can do that because of our transactional capabilities. CouchDB, MongoDB, Cassandra and Riak all have different APIs and we talk to companies that run all of those products side-by-side. The NewSQL database players are also offering a single data model, albeit a very popular one, SQL. FoundationDB is offering an ever increasing number of data models through its “layers”, currently including several popular NoSQL data models and with SQL being the next big one to hit. Our philosophy is that you shouldn’t have to increase the complexity of your architecture by adopting a new NoSQL database each time your engineers need access to a new data model.
Q6. Cloud computing and open source: How does it relate to FoundationDB?
Dave Rosenthal: Cloud computing: FoundationDB has been designed from the beginning to run well in cloud environments that make use of large numbers of commodity machines connected through a network. Probably the most important aspect of a distributed database designed for cloud deployment is exceptional fault tolerance under very harsh and strange failure conditions – the kind of exceptionally unlikely things that can only happen when you have many machines working together with components failing unpredictably. We have put a huge amount of effort into testing FoundationDB in these grueling scenarios, and feel very confident in our ability to perform well in these types of environments. In particular, we have users running FoundationDB successfully on many different cloud providers, and we’ve seen the system keep its guarantees under real-world hardware and network failure conditions experienced by our users.
Open source: Although FoundationDB’s core data storage engine is closed source, our layer ecosystem is open source. Although the core data storage engine has a very simple feature set, and is very difficult to properly modify while maintaining correctness, layers are very feature rich and because they are stateless, are much easier to create and modify which makes them well suited to third-party contributions.
Q7 Pls give some examples of use cases where FoundationDB is currently in use. Is FoundationDB in use for analyzing Big Data as well?
Dave Rosenthal: Some examples: User data, meta data, user social graphs, geo data, via ORMs using the SQL layer, metrics collection, etc.
We’ve mostly focused on operational systems, but a few of our customers have built what I would call “big data” applications, which I think of as analytics-focused. The most common use case has been for collecting and analyzing time-series data. FoundationDB is strongest in big data applications that call for lots of random reads and writes, not just big table scans—which many systems can do well.
Q8. Rick Cattel said in an recent interview  “there aren’t enough open source contributors to keep projects competitive in features and performance, and the companies supporting the open source offerings will have trouble making enough money to keep the products competitive themselves”. What is your opinion on this?
Dave Rosenthal: People have great ideas for databases all the time. New data models, new query languages, etc.
If nothing else, this NoSQL experiment that we’ve all been a part of the past few years has shown us all the appetite for data models suited to specific problems. They would love to be able to build these tools, open source them, etc.
The problem is that the checklist of practical considerations for a database is huge: Fault tolerance, scalability, a backup solution, management and monitoring, ACID transactions, etc. Add those together and even the simplest concept sounds like a huge project.
Our vision at FoundationDB is that we have done the hard work to build a storage substrate that simultaneously solves all those tricky practical problems. Our engine can be used to quickly build a database layer for any particular application that inherits all of those solutions and their benefits, like scalability, fault tolerance and ACID compliance.
Q9. Nick Heudecker of Gartner, predicts that  “going forward, we see the bifurcation between relational and NoSQL DBMS markets diminishing over time” . What is your take on this?
Dave Rosenthal: I do think that the lines between SQL and NoSQL will start to blur and I believe that we are leading that charge.We acquired another database startup last year called Akiban that builds an amazing SQL database engine.
In 2014 we’ll be bringing that engine to market as a layer running on top of FoundationDB. That will be a true ANSI SQL database operating as a module directly on top of a transactional “NoSQL” engine, inheriting the operational benefits of our core storage engine – scalability, fault tolerance, ease of operation.
When you run multiple of the SQL layer modules, you can point many of them at the same key-space in FoundationDB and it’s as if they are all part of the same database, with ACID transactions enforced across the separate SQL layer processes.
It’s very cool. Of course, you can even run the SQL layer on a FoundationDB cluster that’s also supporting other data models, like graph or document. That’s about as blurry as it gets.
Dave Rosenthal is CEO of FoundationDB. Dave started his career in games, building a 3D real-time strategy game with a team of high-school friends that won the 1st annual Independent Games Festival. Previously, Dave was CTO at Visual Sciences, a pioneering web-analytics company that is now part of Adobe. Dave has a degree in theoretical computer science from MIT.
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