Workload management
Discussion of workload management technology, typically in analytic or mixed-workload DBMS.
MarkLogic’s Hadoop connector
It’s time to circle back to a subject I skipped when I otherwise wrote about MarkLogic 5: MarkLogic’s new Hadoop connector.
Most of what’s confusing about the MarkLogic Hadoop Connector lies in two pairs of options it presents you:
- Hadoop can talk XQuery to MarkLogic. But alternatively, Hadoop can use a long-established simple(r) Java API for streaming documents into or out of a MarkLogic database.
- Hadoop can make requests to MarkLogic in MarkLogic’s normal mode of operation, namely to address any node in the MarkLogic cluster, which then serves as a “head” node for the duration of that particular request. But alternatively, Hadoop can use a long-standing MarkLogic option to circumvent the whole DBMS cluster and only talk to one specific MarkLogic node.
Otherwise, the whole thing is just what you would think:
- Hadoop can read from and write to MarkLogic, in parallel at both ends.
- If Hadoop is just writing to MarkLogic, there’s a good chance the process is properly called “ETL.”
- If Hadoop is reading a lot from MarkLogic, there’s a good chance the process is properly called “batch analytics.”
MarkLogic said that it wrote this Hadoop connector itself.
| Categories: Clustering, EAI, EII, ETL, ELT, ETLT, Hadoop, MapReduce, MarkLogic, Parallelization, Workload management | 2 Comments |
Workload management and RAM
Closing out my recent round of Teradata-related posts, here’s a little anomaly:
- Teradata is proud that Teradata 14’s workload management now explicitly manages I/O, to go with Teradata’s long-standing management of CPU. Teradata’s WLM still does not explicitly manage RAM.
- Aster is proud that Aster 5’s workload management now explicitly manages RAM, to go along with the WLM capabilities Aster has had for a while managing CPU and I/O. Aster’s Tasso Argyros believes this is an important capability, at least in some edge cases.
- Mike Pilcher of SAND emailed me that SAND’s WLM capabilities to explicitly manage CPU, I/O, and RAM are very well-received by the marketplace.
| Categories: Aster Data, Data warehousing, SAND Technology, Teradata, Workload management | 4 Comments |
Aster Database Release 5 and Teradata Aster appliance
It was obviously just a matter of time before there would be an Aster appliance from Teradata and some tuned bidirectional Teradata-Aster connectivity. These have now been announced. I didn’t notice anything particularly surprising in the details of either. About the biggest excitement is that Aster is traditionally a Red Hat shop, but for the purposes of appliance delivery has now embraced SUSE Linux.
Along with the announcements comes updated positioning such as:
- Better SQL than the MapReduce alternatives have.
- Better MapReduce than the SQL alternatives have.
- Easy(ier) way to do complex analytics on multi-structured data. (Aster has embraced that term.)
and of course
- Now also with Teradata’s beautifully engineered hardware and system management software!
| Categories: Aster Data, Data warehouse appliances, Data warehousing, Predictive modeling and advanced analytics, Teradata, Workload management | Leave a Comment |
Virtual data marts in Sybase IQ
I made a few remarks about Sybase IQ 15.3 when it became generally available in July. Now that I’ve had a current briefing, I’ll make a few more.
The key enhancement in Sybase IQ 15.3 is distributed query — what others might call parallel query — aka PlexQ. A Sybase IQ query can now be distributed among many nodes, all talking to the same SAN (Storage-Area Network). Any Sybase IQ node can take the responsibility of being the “leader” for that particular query.
In itself, this isn’t that impressive; all the same things could have been said about pre-Exadata Oracle.* But PlexQ goes somewhat further than just removing a bottleneck from Sybase IQ. Notably, Sybase has rolled out a virtual data mart capability. Highlights of the Sybase IQ virtual data mart story include: Read more
| Categories: Columnar database management, Data warehousing, Oracle, Parallelization, Sybase, Theory and architecture, Workload management | 1 Comment |
Hadoop evolution
I wanted to learn more about Hadoop and its futures, so I talked Friday with Arun Murthy of Hortonworks.* Most of what we talked about was:
- NameNode evolution, and the related issue of file-count limitations.
- JobTracker evolution.
Arun previously addressed these issues and more in a June slide deck.
Read more
| Categories: Hadoop, MapReduce, Parallelization, Workload management, Yahoo | 7 Comments |
Eight kinds of analytic database (Part 1)
Analytic data management technology has blossomed, leading to many questions along the lines of “So which products should I use for which category of problem?” The old EDW/data mart dichotomy is hopelessly outdated for that purpose, and adding a third category for “big data” is little help.
Let’s try eight categories instead. While no categorization is ever perfect, these each have at least some degree of technical homogeneity. Figuring out which types of analytic database you have or need — and in most cases you’ll need several — is a great early step in your analytic technology planning. Read more
Vertica as an analytic platform
Vertica 5.0 is coming out today, and delivering the down payment on Vertica’s analytic platform strategy. In Vertica lingo, there’s now a Vertica SDK (Software Development Kit), featuring Vertica UDT(F)s* (User-Defined Transform Functions). Vertica UDT syntax basics start: Read more
| Categories: Analytic technologies, Data warehousing, GIS and geospatial, Predictive modeling and advanced analytics, RDF and graphs, Vertica Systems, Workload management | 7 Comments |
Oracle and IBM workload management
When last night’s Oracle/Exadata post got too long — and before I knew Oracle would request a different section be cut — I set aside my comments on Oracle’s workload management story to post separately. Elements of Oracle’s workload management story include:
- Oracle’s workload management product is called Oracle Database Resource Manager.
- Oracle Database Resource Manager has long managed CPU. For Exadata, Oracle added in management of I/O. Management of RAM is coming.
- Another aspect of Oracle workload management is “instance caging.” If you’re running multiple instances of Oracle on the same box – e.g. one with 128 cores and thus 256 threads – instance caging can keep an instance confined to a specific number of threads.
- Policies can let some classes of user get access to more threads in Oracle Parallel Query than others do.*
- Oracle offers a QoS (Quality of Service) layer, at least on Exadata, that tries to use Oracle’s workload management capabilities to enforce SLAs (Service Level Agreements). For example, if you want a certain query to always be answered in no more than 0.3 seconds, it tries to make that happen. However, this technology is new in the current Oracle release, and will be enhanced going forward.
*Recall that “degrees of parallelism” in Oracle Parallel Query can now be set automagically.
One reason I split out this discussion of workload management is that I also talked with IBM’s Tim Vincent yesterday, who added some insight to what I already wrote last August about DB2/InfoSphere Warehouse workload management. Specifically:
- DB2/InfoSphere Warehouse workload management has multiple ways to manage use of CPU resources.
- DB2/InfoSphere Warehouse workload management doesn’t directly manage consumption of I/O or RAM resources. However, it can influence usage of I/O or RAM by:
- Limiting the number or rows read or returned.
- Adjusting priorities as to which queries get to prefetch the most records.
- DB2/InfoSphere Warehouse workload management doesn’t allow you to directly set an SLA mandating query response time. However, if query response times exceed a target SLA, DB2/InfoSphere Warehouse workload management can cause a statistics dump that might help you tune your way out of the problem.
| Categories: Data warehousing, IBM and DB2, Oracle, Workload management | Leave a Comment |
In-memory, parallel, not-in-database SAS HPA does make sense after all
I talked with SAS about its new approach to parallel modeling. The two key points are:
- SAS no longer plans to go as far with in-database modeling as it previously intended.
- Rather, SAS plans to run in RAM on MPP DBMS appliances, exploiting MPI (Message Passing Interface).
The whole thing is called SAS HPA (High-Performance Analytics), in an obvious reference to HPC (High-Performance Computing). It will run initially on RAM-heavy appliances from Teradata and EMC Greenplum.
A lot of what’s going on here is that SAS found it annoyingly difficult to parallelize modeling within the framework of a massively parallel DBMS such as Teradata. Notes on that aspect include:
- SAS wasn’t exploiting the capabilities of individual DBMS to their fullest; rather, it was looking for an approach that would work across multiple brands of DBMS. Thus, for example, the fact that Aster’s analytic platform architecture is more flexible or powerful than Teradata’s didn’t help much with making SAS run within the Aster nCluster database.
- Notwithstanding everything else, SAS did make a certain set of modeling procedures run in-database.
- SAS’ previous plans to run in-database modeling in Aster and/or Netezza DBMS may never come to fruition.
Comments on the Gartner 2010/2011 Data Warehouse Database Management Systems Magic Quadrant
Edit: Comments on the February, 2012 Gartner Magic Quadrant for Data Warehouse Database Management Systems — and on the companies reviewed in it — are now up.
The Gartner 2010 Data Warehouse Database Management Systems Magic Quadrant is out. I shall now comment, just as I did to varying degrees on the 2009, 2008, 2007, and 2006 Gartner Data Warehouse Database Management System Magic Quadrants.
Note: Links to Gartner Magic Quadrants tend to be unstable. Please alert me if any problems arise; I’ll edit accordingly.
In my comments on the 2008 Gartner Data Warehouse Database Management Systems Magic Quadrant, I observed that Gartner’s “completeness of vision” scores were generally pretty reasonable, but their “ability to execute” rankings were somewhat bizarre; the same remains true this year. For example, Gartner ranks Ingres higher by that metric than Vertica, Aster Data, ParAccel, or Infobright. Yet each of those companies is growing nicely and delivering products that meet serious cutting-edge analytic DBMS needs, neither of which has been true of Ingres since about 1987. Read more