JPS - Java Virtual Machine Process Status Tool
Find all java process in a host:C:\Program Files\Java\jdk1.7.0_79\bin>jps -lv 6192 sun.tools.jps.Jps -Dapplication.home=C:\Program Files\Java\jdk1.7.0_79 -Xms8m 5348 C:\Desarrollo\eclipse-neon-2\\plugins/org.eclipse.equinox.launcher_1.3.201.v20161025-1711.jar -Dosgi.requiredJavaVersion=1.8 -XX:+UseG1GC -XX:+UseStringDeduplication -Dosgi.requiredJavaVersion=1.8 -Xms256m -Xmx2048m 3496 org.jboss.modules.Main -agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:49626 -Dprogram.name=JBossTools: Red Hat JBoss EAP 6.1+ -Xms512m -Xmx1024m -XX:MaxPermSize=512m -Dorg.jboss.resolver.warning=true -Djava.net.preferIPv4Stack=true -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true -Dorg.jboss.boot.log.file=C:/Servers/jboss-eap-6.2/standalone/log/boot.log -Dlogging.configuration=file:/C:/Servers/jboss-eap-6.2/standalone/configuration/logging.properties -Djboss.home.dir=C:/Servers/jboss-eap-6.2 -Dorg.jboss.logmanager.nocolor=true -Djboss.bind.address.management=localhost -Dfile.encoding=Cp1252
JMAP - Memory analysis
Print heap usage sumary:C:\Program Files\Java\jdk1.7.0_79\bin>jmap -heap 3496 Attaching to process ID 3496, please wait... Debugger attached successfully. Server compiler detected. JVM version is 24.79-b02 using thread-local object allocation. Parallel GC with 4 thread(s) Heap Configuration: MinHeapFreeRatio = 0 MaxHeapFreeRatio = 100 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 1310720 (1.25MB) MaxNewSize = 17592186044415 MB OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 21757952 (20.75MB) MaxPermSize = 536870912 (512.0MB) G1HeapRegionSize = 0 (0.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 241172480 (230.0MB) used = 101086072 (96.40319061279297MB) free = 140086408 (133.59680938720703MB) 41.914430701214336% used From Space: capacity = 56623104 (54.0MB) used = 0 (0.0MB) free = 56623104 (54.0MB) 0.0% used To Space: capacity = 56623104 (54.0MB) used = 0 (0.0MB) free = 56623104 (54.0MB) 0.0% used PS Old Generation capacity = 358088704 (341.5MB) used = 194474744 (185.46556854248047MB) free = 163613960 (156.03443145751953MB) 54.30909766983323% used PS Perm Generation capacity = 296222720 (282.5MB) used = 144879144 (138.16751861572266MB) free = 151343576 (144.33248138427734MB) 48.90885614715846% used 44021 interned Strings occupying 5210120 bytes.
Print heap histogram:
C:\Program Files\Java\jdk1.7.0_79\bin>jmap -histo 3496 num #instances #bytes class name ---------------------------------------------- 1: 105723 53508480 [B 2: 577164 46177512 [C 3: 245156 35415432 <constMethodKlass> 4: 245156 31391216 <methodKlass> 5: 25900 28928112 <constantPoolKlass> 6: 628395 25135800 java.util.LinkedHashMap$Entry [...] 11430: 1 16 org.jboss.as.platform.mbean.ThreadMXBeanFindDeadlockedThreadsHandler 11431: 1 16 org.jboss.msc.service.ServiceContainerImpl$4 11432: 1 16 org.jboss.as.jmx.JMXExtension$JMXSubsystemParser_1_3 Total 8243462 503304768
JCMD
Show JVM Information:C:\Program Files\Java\jdk1.7.0_79\bin>jcmd 3496 help 3496: The following commands are available: VM.native_memory VM.commercial_features GC.rotate_log ManagementAgent.stop ManagementAgent.start_local ManagementAgent.start Thread.print GC.class_histogram GC.heap_dump GC.run_finalization GC.run VM.uptime VM.flags VM.system_properties VM.command_line VM.version help For more information about a specific command use 'help <command>'.
Print all JVM Threads:
C:\Program Files\Java\jdk1.7.0_79\bin>jcmd 3496 help Thread.print
3496:
Thread.print
Print all threads with stacktraces.
Impact: Medium: Depends on the number of threads.
Syntax : Thread.print [options]
Options: (options must be specified using the <key> or <key>=<value> syntax)
-l : [optional] print java.util.concurrent locks (BOOLEAN, false)
C:\Program Files\Java\jdk1.7.0_79\bin>jcmd 3496 Thread.print
[...]
Generate a Heap dump:
C:\Program Files\Java\jdk1.7.0_79\bin>jcmd 3496 help GC.heap_dump
3496:
GC.heap_dump
Generate a HPROF format dump of the Java heap.
Impact: High: Depends on Java heap size and content. Request a full GC unless the '-all' option is specified.
Syntax : GC.heap_dump [options] <filename>
Arguments:
filename : Name of the dump file (STRING, no default value)
Options: (options must be specified using the <key> or <key>=<value> syntax)
-all : [optional] Dump all objects, including unreachable objects (BOOLEAN, false)
C:\Program Files\Java\jdk1.7.0_79\bin>jcmd 3496 GC.heap_dump D:\tmp\test_jboss.hpprof
3496:
Heap dump file created
Important!! When you execute a heap dump, the JVM performs a garbage collector first. Therefore you will not get the heap´s snapshot, but a cleaner version.
JSTAT
Monitor Garbage Colector:Program Files\Java\jdk1.7.0_79\bin>jstat -options -cl -compiler -gc -gccapacity -gccause -gcnew -gcnewcapacity -gcold -gcoldcapacity -gcpermcapacity -gcutil -printcompilation C:\Program Files\Java\jdk1.7.0_79\bin>jstat -gcutil 3496 1000 S0 S1 E O P YGC YGCT FGC FGCT GCT 0,00 24,73 88,78 72,67 99,92 23 0,973 0 0,000 0,973 0,00 24,73 88,79 72,67 99,92 23 0,973 0 0,000 0,973 0,00 24,73 89,02 72,67 99,92 23 0,973 0 0,000 0,973
