Drools：如何设置多线程（multithreadEvaluation）7.34.0 -Java Maven Spring

Question

I see that multithreadEvaluation is set to false by default. I have a simple Maven Spring Drools implementation using spreadsheet decision tables.

There's not much to it as it's basically a standard installation. I have a restful API and when using jmeter to POST to our endpoint, the entity is populated and then we fire all rules on it. When using multiple threads in jmeter, I can clearly see that multithreading is not working.

From the documentation:

You can enable multithreaded evaluation using one of the following options: Enable the multithreaded evaluation system property: drools.multithreadEvaluation=true

Enable multithreaded evaluation while creating the KIE base programmatically:

 KieServices ks = KieServices.Factory.get(); KieBaseConfiguration kieBaseConf = ks.newKieBaseConfiguration(); kieBaseConf.setOption(MultithreadEvaluationOption.YES); KieBase kieBase = kieContainer.newKieBase(kieBaseConf);

Tried adding drools.multithreadedEvaluation=true to application.properties. Didn't resolve the issue.

Tried the second method within the kieSession() @Bean, but the kieBase is not used and it didn't resolve the issue. Currently unsure if simply instantiating the KieBase is sufficient. Where should this go? The method returns kContainer.newKieSession() so not sure how to tell if the kieBaseConf.setOption(MultithreadEvaluationOption.YES) actually did anything.

Tried and failed to create a new kieSession prior to fireAllRules. That service is @Autowired to a kieSession @Bean.

First time working with literally this entire tech stack so thank you for taking it slow.

TL;DR Need step by step instructions how to set drools.multithreadEvaluation to true.

Answer 1

As per documentation Drools expects the System property to be set, while you are setting it in application.properties , which I assume is Spring-related? Try setting it one of the following ways:

1. When launching your application add "-Ddrools.multithreadEvaluation" to the command line, eg:

   java -Ddrools.multithreadEvaluation <the rest of parameters>

2. Or set it programmatically on the application start-up early on initialization before any Drools classes are invoked:

   System.setProperty("drools.multithreadEvaluation", "true");