JRT | UNREAL agent described in Sim-Real Joint Reinforcement | Reinforcement Learning library

I finally found the problem why I could not export files with p:dataExporter.

The web.xml file contained the context param javax.faces.PARTIAL_STATE_SAVING defined to false, so I commented out and I worked well!

The problem in web.xml

Eclipse uses Java in two ways. It runs Eclipse with Java, and it allows specifying Java Runtime Environments in Preferences. I rarely see any reason to set JAVA_HOME anymore, because I specify the paths to the JDKs I want to use. I always have multiple JDKs installed.

I specify which JDK to use to run Java by setting the "-vm" path in the "eclipse.ini" file (which points to the "bin" directory).

I specify which JDK to use to compile code by adding JREs in preferences, and sometimes editing the "Execution Environments" (subsection of "Java Runtime Environments") to point to specific JREs.

Your ZKM Script "open" statement specifies the {"*.class"} file filter. So you are filtering out ALL non-class files including your MANIFEST.MF. See https://www.zelix.com/klassmaster/docs/openStatement.html#filter.

A missing MANIFEST.MF will give you a "Invalid or corrupt jarfile" error. Note that your Zelix KlassMaster log file will contain messages like the following.

MESSAGE: Filtering out path 'obfuscateFatJar.jar!META-INF/MANIFEST.MF' because it does not match specified filter '{".class"}>' (D)*

You can work around this by not using a file filter (the safest option in this case) or by broadening your file filter to include other file types. E.g. {".class" || ".MF"}

The stack trace indicates that the issue is connected with the module loading rather than class loading, which explains why you don’t have the problem in JDK 8 that doesn’t have modules.

When you read the stack trace starting at the bottom, i.e.

The JRT namespace has been introduced with Java 9. You cannot access module data with Java 8 and below.

Allow me to quote the migration guide:

Class and resource files previously stored in lib/rt.jar, lib/tools.jar, lib/dt.jar and various other internal JAR files are stored in a more efficient format in implementation-specific files in the lib directory.

You are adding the lib/ dir instead of bin/.

Don't forget to add bin/ to the %Path% environment variable.

Make sure you don't have duplicates from earlier versions of the jdk/jre.

Sorry, you are adding the jdk instead of the jre that is expected:

https://www.java.com/de/download/help/download_options.xml

From my experience performance problems with JDKs are related mostly to one of the following:

• JIT Compilation
• VM configuration (heap sizes)
• GC algorithm
• Changes in the JVM/JDK which break known good running applications
• (Oh, and I forgot to mention class loading...)

If you just use the default JVM configuration since OpenJDK11, maybe you should set some of the more prominent options to fixed values, like GC, Heap size, etc.

Maybe some graphical analyse tool could help track your issue down. Like Retrace, AppDynamics or FlightRecorder and the like. These give more overview on the overall state of heap, GC cycles, RAM, threads, CPU load and so on at a given time than log files could provide.

Do I understand correctly that your application writes about 30710 lines to the log within the first second of running (under OpenJDK11)? Why is it "only" writing about 7k lines under OpenJDK14 in the first second? This seems like a huge difference for an application that is just started on different JVMs to me... Are you sure there are not for example high amounts of Exception stacktraces dumped into the log?

The other numbers are even higher sometimes, so maybe the slowdowns are related to exception logging? Or even swapping, if RAM gets low?

Actually I am thinking, if an application does not write anything into the log, this is a sign of smooth running without problems (unless it is frozen entirely in this time). What is happening from seconds 12-22 (in the OpenJDK14 case here) is what would concern me more... the logged lines go through the roof... why?

And afterwards the logging goes down to all time low values of about 1-2k lines... what is the reason for that?? (Well, maybe it is the GC kicking in at second 22 and does a tabula rasa which resolves some things...?)

Another thing may be your statement about "single CPU" machines. Does this imply "single core" also (Idk, maybe your software is tailored on legacy hardware or something)?

And the "single CPU" VMs are running on those machines? But I assume, I am wrong about these assumptions, since almost all CPUs are multicore nowadays... but I would investigate on a multithreading issue (deadlock) problem maybe.

At last this issue has been solved by adding the custome data source properties , as mentioned below in the spring boot application.yml file. Hope this helps others. These properties were validated at sybase db. (its application specific validation) .