Hadoop
Discussion of Hadoop. Related subjects include:
Investigative analytics and untrusted code — a quick note
This is probably a good time to disclose that I own a chunk of founders’ stock — no, I didn’t pay cash for it — in LiteStack, the start-up sponsoring ZeroVM.
Jordan Novet posted a survey of Hadoop security, and evidently Merv Adrian is making a big deal about the subject as well. But there’s one point I rarely see mentioned which, come to think of it, could apply to relational analytic platforms as well.
A big use of Hadoop and analytic platforms alike is investigative analytics, and specifically experimentation via hastily-written code. But untrusted code can, at least in theory, compromise the security of the servers it runs on. And when you run the code on the same servers that manage the data, that could compromise the security of your database as well.
Frankly, in most use cases I doubt this is a big deal. Process isolation would probably avert most “accidental attacks”, and a deliberate attack might be hard to pull off in a reliable manner. As for database corruption, also a theoretical danger via the same vector — that danger is much smaller than the risk of bad code being submitted by well-intentioned doofuses.
Still, I’d like to see a forthright discussion of this threat.
| Categories: Hadoop | 2 Comments |
More notes on predictive modeling
My July 2 comments on predictive modeling were far from my best work. Let’s try again.
1. Predictive analytics has two very different aspects.
Developing models, aka “modeling”:
- Is a big part of investigative analytics.
- May or may not be difficult to parallelize and/or integrate into an analytic RDBMS.
- May or may not require use of your whole database.
- Generally is done by humans.
- Often is done by people with special skills, e.g. “statisticians” or “data scientists”.
More precisely, some modeling algorithms are straightforward to parallelize and/or integrate into RDBMS, but many are not.
Using models, most commonly:
- Is done by machines …
- … that “score” data according to the models.
- May be done in batch or at run-time.
- Is embarrassingly parallel, and is much more commonly integrated into analytic RDBMS than modeling is.
2. Some people think that all a modeler needs are a few basic algorithms. (That’s why, for example, analytic RDBMS vendors are proud of integrating a few specific modeling routines.) Other people think that’s ridiculous. Depending on use case, either group can be right.
3. If adoption of DBMS-integrated modeling is high, I haven’t noticed.
| Categories: Ayasdi, Data warehousing, Hadoop, Health care, IBM and DB2, KXEN, Predictive modeling and advanced analytics, SAS Institute | 6 Comments |
Notes and comments, July 2, 2013
I’m not having a productive week, part of the reason being a hard drive crash that took out early drafts of what were to be last weekend’s blog posts. Now I’m operating from a laptop, rather than my preferred dual-monitor set-up. So please pardon me if I’m concise even by comparison to my usual standards.
- My recent posts based on surveillance news have been partly superseded by – well, by more news. Some of that news, along with some good discussion, may be found in the comment threads.
- The same goes for my recent Hadoop posts.
- The replay for my recent webinar on real-time analytics is now available. My part ran <25 minutes.
- One of my numerous clients using or considering a “real-time analytics” positioning is Sqrrl, the company behind the NoSQL DBMS Accumulo. Last month, Derrick Harris reported on a remarkable Accumulo success story – multiple US intelligence instances managing 10s of petabytes each, and supporting a variety of analytic (I think mainly query/visualization) approaches.
- Several sources have told me that MemSQL’s Zynga sale is (in part) for Membase replacement. This is noteworthy because Zynga was the original pay-for-some-of-the-development Membase customer.
- More generally, the buzz out of Couchbase is distressing. Ex-employees berate the place; job-seekers check around and then decide not to go there; rivals tell me of resumes coming out in droves. Yes, there’s always some of that, even at obviously prospering companies, but this feels like more than the inevitable low-level buzz one hears anywhere.
- I think the predictive modeling state of the art has become:
- Cluster in some way.
- Model separately on each cluster.
- And if you still want to do something that looks like a regression – linear or otherwise – then you might want to use a tool that lets you shovel training data in WITHOUT a whole lot of preparation* and receive a model back out. Even if you don’t accept that as your final model, it can at least be a great guide to feature selection (in the statistical sense of the phrase) and the like.
- Champion/challenger model testing is also a good idea, at least if you’re in some kind of personalization/recommendation space, and have enough traffic to test like that.**
- Most companies have significant turnover after being acquired, perhaps after a “golden handcuff” period. Vertica is no longer an exception.
- Speaking of my clients at HP Vertica – they’ve done a questionable job of communicating that they’re willing to price their product quite reasonably. (But at least they allowed me to write about $2K/terabyte for hardware/software combined.)
- I’m hearing a little more Amazon Redshift buzz than I expected to. Just a little.
- StreamBase was bought by TIBCO. The rumor says $40 million.
*Basic and unavoidable ETL (Extract/Transform/Load) of course excepted.
**I could call that ABC (Always Be Comparing) or ABT (Always Be Testing), but they each sound like – well, like The Glove and the Lions.
Hadoop news and rumors, June 23, 2013
Cloudera
- Cloudera changed CEOs last week. Tom Reilly, late of ArcSight, is the new guy (I don’t know him), while Mike Olson’s titles become Chairman and Chief Strategy Officer. Mike told me Friday that Reilly had secretly been working with him for months.
- Mike shared good-sounding numbers with me. But little is for public disclosure except the stat >400 employees.
- There are always rumors of infighting at Cloudera, perhaps because from earliest days Cloudera was a place where tempers are worn on sleeves. That said, Mike denied stories of problems between him and COO Kirk Dunn, and greatly praised Kirk’s successes at large-account sales.
- Cloudera now self-identifies pretty clearly as an analytic data management company. The vision is multiple execution engines – MapReduce, Impala, something more memory-centric, etc. – talking to any of a variety of HDFS file formats. While some formats may be optimized for specific engines – e.g. Parquet for Impala – anything can work with more or less anything.*
- Mike told me that Cloudera didn’t have any YARN users in production, but thought there would be some by year-end. Even so, he thinks it’s fair to say that Cloudera users have substantial portions of Hadoop 2 in production, for example NameNode failover and HDFS (Hadoop Distributed File System) performance enhancements. Ditto HCatalog.
*Of course, there will always be exceptions. E.g., some formats can be updated on a short-request basis, while others can only be written to via batch conversions.
Everybody else
- There’s a widespread belief that Hortonworks is being shopped. Numerous folks – including me — believe the rumor of an Intel offer for $700 million. Higher figures and alternate buyers aren’t as widely believed.
- Views of MapR market traction, never high, are again on the downswing.
- IBM Big Insights seems to have some traction.
- In case there was any remaining doubt — DBMS vendors are pretty unanimous in agreeing that it makes sense to have Hadoop too. To my knowledge SAP hasn’t been as clear about showing a markitecture incorporating Hadoop as most of the others have … but then, SAP’s markitecture is generally less clear than other vendors’.
- Folks I talk with are generally wondering where and why Datameer lost its way. That still leaves Datameer ahead of other first-generation Hadoop add-on vendors (Karmasphere, Zettaset, et al.), in that I rarely hear them mentioned at all.
- I visited with my client Platfora. Things seem to be going very well.
- My former client Revelytix seems to have racked up some nice partnerships. (I had something to do with that. :))
| Categories: Cloudera, Data warehousing, Datameer, Hadoop, Hortonworks, IBM and DB2, Intel, MapR, Market share and customer counts, Platfora, SAP AG, Zettaset | 11 Comments |
Impala and Parquet
I visited Cloudera Friday for, among other things, a chat about Impala with Marcel Kornacker and colleagues. Highlights included:
- Impala is meant to someday be a competitive MPP (Massively Parallel Processing) analytic RDBMS.
- At the moment, it is not one. For example, Impala lacks any meaningful form of workload management or query optimization.
- While Impala will run against any HDFS (Hadoop Distributed File System) file format, claims of strong performance assume that the data is in Parquet …
- … which is the replacement for the short-lived Trevni …
- … and which for most practical purposes is true columnar.
- Impala is also meant to be more than an RDBMS; Parquet and presumably in the future Impala can accommodate nested data structures.
- Just as Impala runs against most or all HDFS file formats, Parquet files can be used by most Hadoop execution engines, and of course by Pig and Hive.
- The Impala roadmap includes workload management, query optimization, data skipping, user-defined functions, hash distribution, two turtledoves, and a partridge in a pear tree.
Data gets into Parquet via batch jobs only — one reason it’s important that Impala run against multiple file formats — but background format conversion is another roadmap item. A single table can be split across multiple formats — e.g., the freshest data could be in HBase, with the rest is in Parquet.
Where things stand in US government surveillance
Edit: Please see the comment thread below for updates. Please also see a follow-on post about how the surveillance data is actually used.
US government surveillance has exploded into public consciousness since last Thursday. With one major exception, the news has just confirmed what was already thought or known. So where do we stand?
My views about domestic data collection start:
- I’ve long believed that the Feds — specifically the NSA (National Security Agency) — are storing metadata/traffic data on every telephone call and email in the US. The recent news, for example Senator Feinstein’s responses to the Verizon disclosure, just confirms it. That the Feds sometimes claim this has to be “foreign” data or they won’t look at it hardly undermines my opinion.
- Even private enterprises can more or less straightforwardly buy information about every credit card purchase we make. So of course the Feds can get that as well, as the Wall Street Journal seems to have noticed. More generally, I’d assume the Feds have all the financial data they want, via the IRS if nothing else.
- Similarly, many kinds of social media postings are aggregated for anybody to purchase, or can be scraped by anybody who invests in the equipment and bandwidth. Attensity’s service is just one example.
- I’m guessing that web use data (http requests, search terms, etc.) is not yet routinely harvested by the US government.* Ditto deanonymization of same. I guess that way basically because I’ve heard few rumblings to the contrary. Further, the consumer psychographic profiles that are so valuable to online retailers might be of little help to national security analysts anyway.
- Video surveillance seems likely to grow, from fixed cameras perhaps to drones; note for example the various officials who called for more public cameras after that Boston Marathon bombing. But for the present discussion, that’s of lesser concern to me, simply because it’s done less secretively than other kinds of surveillance. If there’s a camera that can see us, often we can see it too.
*Recall that these comments are US-specific. Data retention legislation has been proposed or passed in multiple countries to require recording of, among other things, all URL requests, with the stated goal of fighting either digital piracy or child pornography.
As for foreign data: Read more
| Categories: Hadoop, HP and Neoview, Petabyte-scale data management, Pricing, Surveillance and privacy, Telecommunications, Text, Vertica Systems, Web analytics | 10 Comments |
Dave DeWitt responds to Daniel Abadi
A few days ago I posted Daniel Abadi’s thoughts in a discussion of Hadapt, Microsoft PDW (Parallel Data Warehouse)/PolyBase, Pivotal/Greenplum Hawq, and other SQL-Hadoop combinations. This is Dave DeWitt’s response. Emphasis mine.
Read more
| Categories: Benchmarks and POCs, Cloudera, Clustering, Data warehousing, Greenplum, Hadapt, Hadoop, MapReduce, Microsoft and SQL*Server, PostgreSQL, SQL/Hadoop integration | 6 Comments |
SQL-Hadoop architectures compared
The genesis of this post is:
- Dave DeWitt sent me a paper about Microsoft Polybase.
- I argued with Dave about the differences between Polybase and Hadapt.
- I asked Daniel Abadi for his opinion.
- Dan agreed with Dave, in a long email …
- … that he graciously permitted me to lightly-edit and post.
I love my life.
Per Daniel (emphasis mine): Read more
| Categories: Aster Data, Data warehousing, Greenplum, Hadapt, Hadoop, MapReduce, Microsoft and SQL*Server, SQL/Hadoop integration, Theory and architecture | 13 Comments |
WibiData and its Kiji technology
My clients at WibiData:
- Think they’re an application software company …
- … but actually are talking about what I call analytic application subsystems.
- Haven’t announced or shipped any of those either …
- … but will shortly.
- Have meanwhile shipped some cool enabling technology.
- Name their products after sushi restaurants.
Yeah, I like these guys. 🙂
If you’re building an application that “obviously” calls for a NoSQL database, and which has a strong predictive modeling aspect, then WibiData has thought more cleverly about what you need than most vendors I can think of. More precisely, WibiData has thought cleverly about your data management, movement, crunching, serving, and integration. For pure modeling sophistication, you should look elsewhere — but WibiData will gladly integrate with or execute those models for you.
WibiData’s enabling technology, now called Kiji, is a collection of modules, libraries, and so on — think Spring — running over Hadoop/HBase. Except for some newfound modularity, it is much like what I described at the time of WibiData’s launch or what WibiData further disclosed a few months later. Key aspects include:
- A way to define schemas in HBase, including ones that change as rapidly as consumer-interaction applications require.
- An analytic framework called “Produce/Gather”, which can execute at human real-time speeds (via its own execution engine) or with higher throughput in batch mode (by invoking Hadoop MapReduce).
- Enough load capabilities, Hive interaction, and so on to get data into the proper structure in Kiji in the first place.
| Categories: Hadoop, HBase, NoSQL, Open source, Predictive modeling and advanced analytics, WibiData | 5 Comments |
Syncsort extends Hadoop MapReduce
My client Syncsort:
- Is an ETL (Extract/Transform/Load) vendor, whose flagship product DMExpress was evidently renamed to DMX.
- Has a strong history in and fondness for sort.
- Has announced a new ETL product, DMX-h ETL Edition, which uses Hadoop MapReduce to parallelize DMX by controlling a copy of DMX that resides on every data node of the Hadoop cluster.*
- Has also announced the closely-related DMX-h Sort Edition, offering acceleration for the sorts inherent in Map and Reduce steps.
- Contributed a patch to Apache Hadoop to open up Hadoop MapReduce to make all this possible.
*Perhaps we should question Syncsort’s previous claims of having strong multi-node parallelism already. 🙂
The essence of the Syncsort DMX-h ETL Edition story is:
- DMX-h inherits the various ETL-suite trappings of DMX.
- Syncsort claims DMX-h has major performance advantages vs., for example, Hive- or Pig-based alternatives.
- With a copy of DMX on every node, DMX-h can do parallel load/export.
More details can be found in a slide deck Syncsort graciously allowed me to post. Read more
| Categories: Cloudera, Clustering, EAI, EII, ETL, ELT, ETLT, Hadoop, MapReduce, Syncsort | 8 Comments |