Package blasd.apex.core.jvm

Interface Summary

Interface	Description
IApexGarbageCollectionNotificationInfo	Wraps the not-specified but much useful information in com.sun.management.GarbageCollectionNotificationInfo
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 -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
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.
IGCInspector	Interface for GC activity monitoring

Class Summary

Class	Description
ApexForOracleJVM	Holds all call to methods/fields not in the Java spec but present in the Oracle jvm
ApexGarbageCollectionNotificationInfo	Wrap the usage of GarbageCollectionNotificationInfo which is restricted API
ApexMathHelper	Helpers related to math and numbers
GCInspector	This class registers itself as listener on GC events.