This week Albin Carpentier and I helped to run JRules memory consumption benchmarks on IBM zSeries. Within R&D we have 24x7 remote access to a machine we rent from IBM in Dallas, Texas. A large bank in Europe is evaluating deploying JRules on the mainframe and Albin was able to quickly deploy the Rule Execution Server to WebSphere and DB2 running on z/OS so we could gather memory consumption statistics to help inform their decision.
The configuration tested was: zOS 1.9, DB2 8.1, WebSphere Application Server 22.214.171.124 and IBM JDK 5.
We used a proof of concept ruleset containing representative rules that were cloned to create rulesets with 33, 66, 132, 264 and 528 rules. Memory consumption was measured using the JDK 5 MemoryMXBean and MemoryPoolMXBean. We ran three scenarios:
- Invoking the engine within a JVM (no WebSphere) using IlrContext,
- Rule Execution Server on WAS using J2SE provider,
- Rule Execution Server on WAS using POJO provider.
The product performed very well and we saw linear scalability in all three scenarios. The highest heap memory usage we saw was a very modest 35 MB on WebSphere with the Rule Execution Server.