[jboss-jira] [JBoss JIRA] Resolved: (JBRULES-3116) Performance Regression due to mvel ParserContext now set, resulting in CompositeClassLoader loads

Performance Regression due to mvel ParserContext now set, resulting in CompositeClassLoader loads ------------------------------------------------------------------------------------------------- Key: JBRULES-3116 URL: https://issues.jboss.org/browse/JBRULES-3116 Project: Drools Issue Type: Bug Security Level: Public(Everyone can see) Components: drools-compiler Affects Versions: 5.2.0.Final Reporter: Fabian Lange Assignee: Mario Fusco Attachments: abstractParser-bug1.png I observed this issue already with 5.1, but now had time to verify it with 5.2. Initial compilation time has exploded with those versions. I have with the same test cases with 5.2 this: {{org.drools.util.CompositeClassLoader$CachingLoader.load}} taking a total of 42 seconds With 5.0 (where this Caching was not yet implemented) I had a total time of less than 5 seconds spend in the ClassLoading. The reason for this took me a while to find, but now I do have it: {{org.mvel2.compiler.AbstractParser.createPropertyToken}} is invoking {{hasImports()}} and {{getImport()}} on the ParseContext if not null: see: https://github.com/mikebrock/mvel/blob/master/src/main/java/org/mvel2/com... Those in turn are invoking {{org.mvel2.ParserConfiguration.checkForDynamicImport}} which invokes {{org.drools.util.CompositeClassLoader.loadClass}} This is invoked on my table for expressions like this: "{{age >= 16}}" So the {{org.drools.util.CompositeClassLoader$CachingLoader.load}} will look for a class called "age" and a class called "16". Because the class not exists null/false are returned from the callchain. However neither the {{CachingLoader}}, nor the Map in {{AbstractParser}} will cache the negative result. Causing this to happen for each row in my decisiontable. And in 5.0 the whole part of the callgraph is not there. I figured out, that in 5.0 versions, the {{AbstractParser}} never had a parse context in createPropertyToken This might be because of the inconsistent usage of {code} protected static ThreadLocal<ParserContext> parserContext; protected ParserContext pCtx; {code} So where does us leave this? A possible easy solution would be to add the "negative" lookups to the CachingLoader. However I would like to have doublechecked if the change in Abstract Parser was intentional and is now working correctly. Thus invoking the checkDynamicImports a lot is correct. Is it really the case that the parser needs to check for each literal this dynamic import thing? it obviously didnt do before.