blasd.apex.core.jvm

Interface IApexJVMConstants

public interface IApexJVMConstants

Typical JVM arguments Class memory parameterization -XX:+UseG1GC -XX:+ExplicitGCInvokesConcurrent -Xmx3G -Xms3G -XX:MaxDirectMemorySize=7G -XX:MaxPermSize=512M Enable HeapDump on OutOfMemoryError -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/disk2/dumps -DbufferAllocatorClass=com.qfs.buf.impl.HeapBufferAllocator -DchunkAllocatorClass=com.qfs.chunk.buffer.impl.HeapBufferChunkAllocator -DdefaultChunkSize=131072 -DchunkAllocatorClass=com.qfs.chunk.direct.impl.DirectChunkAllocator -DchunkAllocatorClass=com.qfs.chunk.direct.impl.MmapDirectChunkAllocator -DchunkAllocatorClass=com.qfs.chunk.direct.allocator.impl.SlabMemoryAllocator java -XX:+PrintFlagsFinal -version > flags.log -XX:+PrintGCApplicationStoppedTime - it prints all STW pauses not only related to GC -XX:+PrintSafepointStatistics - prints safe points details -XX:PrintSafepointStatisticsCount=1 - make JVM report every safe point <%p> will add the PID in the gcLogFile <%t> will add the startup date in the gcLogFile https://bugs.openjdk.java.net/browse/JDK-6950794 Minimum logs in sysout -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps For -Xloggc, %p.%t are very important else gc logs will be overriden on each restart -Xloggc:../log/jvm_gc.%p.%t.log -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -XX:+PrintClassHistogramBeforeFullGC -XX:+PrintClassHistogramAfterFullGC -XX:+PrintGCApplicationStoppedTime -XX:+PrintSafepointStatistics –XX:PrintSafepointStatisticsCount=1 GC rolling -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 XX:GCLogFileSize=10M In Prod -XX:-OmitStackTraceInFastThrow will prevent cutting stacks, even if at least the first stack occurence has been complete JGroups does not work with IPv6 -Djava.net.preferIPv4Stack=true # CheckIP with: hostname -i -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=1088 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=

Typical monitoring commands jmap jmap -histo jmap -histo -F > some.file jmap -dump:format=b,file= -J-Dsun.tools.attach.attachTimeout= jstat -gclog jstack jstack -F Add debug in tomcat: "-Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n" JIT Class Compilation audit -XX:+UnlockDiagnosticVMOptions -XX:+LogCompilation -XX:+TraceClassLoading Optionally add -XX:+PrintAssembly https://github.com/AdoptOpenJDK/jitwatch/ https://github.com/AdoptOpenJDK/jitwatch/wiki/Instructions Profiling based on ThreadDumps http://techblog.netflix.com/2015/07/java-in-flames.html Ensure stack-traces are present: -XX:-OmitStackTraceInFastThrow http://stackoverflow.com/questions/2411487/nullpointerexception-in-java-with-no-stacktrace

Author:

Benoit Lacelle

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	IApexJVMConstants.IApexJMCConstants Enable Java Mission Control http://docs.oracle.com/cd/E15289_01/doc.40/e15070/usingjfr.htm -XX:+UnlockCommercialFeatures -XX:+FlightRecorder https://docs.oracle.com/cd/E15289_01/doc.40/e15070/config_rec_data.htm Start from startup.