JCMD(1) JDK JCMD(1) (NAME) jcmd - OpenJDK 21 (SYNOPSIS) jcmd [pid | main-class] command... | PerfCounter.print | -f filename jcmd [-l] jcmd -h pid jcmd . main-class jcmd . command command jcmd JVM . jcmd help (jcmd pid help) pid . pid 0 . . ( -l). Perfcounter.print . -f filename filename . -l . JVM ps PID . : jcmd jcmd -l . -h jcmd . (DESCRIPTION) jcmd JVM . JVM JVM . . . : jcmd pid help command (' ") . (\) . ( ). (pid) (main-class) jcmd . 0 . JCMD (COMMANDS FOR JCMD) command jcmd JVM . jcmd help (jcmd pid help) pid . pid 0 . . ( -l). : help [options] [arguments] . arguments: o command name: (STRING ) : (options) key key=value . options: o -all: () (BOOLEAN false). Compiler.codecache (code cache) . : Compiler.codelist . : Compiler.perfmap ( ) perf . : Compiler.queue . : Compiler.directives_add *filename* *arguments* . : arguments: filename: (STRING ) Compiler.directives_clear . : Compiler.directives_print . : Compiler.directives_remove . : GC.class_histogram [options] . : --- . : options key key=value . options: o -all: () (BOOLEAN false) o -parallel: () . 0 () VM . 1 ( ) . VM . (INT 0) GC.finalizer_info Finalization . : GC.heap_dump [options] [arguments] HPROF . : --- . GC -all . : (options) key key=value . options: o -all: () (BOOLEAN false) o -gz: () gzipped . 1 () 9 . (INT 1) o -overwrite: () (BOOLEAN false) arguments: o filename: (STRING ) GC.heap_info . : GC.run java.lang.System.gc() . : --- . GC.run_finalization java.lang.System.runFinalization() . : --- . JFR.check [options] . : : options key key=value . . options: o name: () . (STRING ) o verbose: () (BOOLEAN false) JFR.configure [options] . : : options key key=value . . options: o globalbuffercount: () . : memorysize . JFR . (STRING memorysize ) o globalbuffersize: () . : memorysize . JFR . (STRING memorysize ) o maxchunksize: () : 'm' 'M' 'g' 'G' . JFR . (STRING 12M) o memorysize: () : 'm' 'M' 'g' 'G' . JFR . (STRING 10M) o repositorypath: () . (STRING . /tmp . TMP .) o preserve-repository={true|false} : JVM . false . . o stackdepth: () . 64 . JFR . (LONG 64) o thread_buffer_size: () : 'k' 'K' 'm' 'M' . . JFR . (STRING 8k) o samplethreads: () . (BOOLEAN true) JFR.dump [options] : : options key key=value . . . options: o begin: () . . (STRING ) o end: () . . (STRING ) : begin end java.time.LocalTime::parse(STRING) java.time.LocalDateTime::parse(STRING) java.time.Instant::parse(STRING) . "13:20:15" "2020-03-17T09:00:00" "2020-03-17T09:00:00Z". : begin end . "s" "m" "h" . "-12h" "-15m" "-30s" o filename: () . PID . PID . %p / %t PID . (STRING ) o maxage: () . (INTEGER 's' 'm' 'h' ) o maxsize: () : 'm' 'M' 'g' 'G' . (STRING ) o name: () . . (STRING ) o path-to-gc-root: () (GC) . . . (BOOLEAN false) JFR.start [options] : : options key key=value . . options: o delay: () (INTEGER 's' 'm' 'h' 0s) o disk: () (BOOLEAN true) o dumponexit: () (JVM). 'true' filename . . ( : id-1-2019_12_12_10_41.jfr) (BOOLEAN false) o duration: () . 0s (INTEGER 's' 'm' 'h' 0s) o filename: () . PID . PID . %p / %t PID . (STRING ) o maxage: () . disk true . 0s . (INTEGER 's' 'm' 'h' 0s) o maxsize: () : 'm' 'M' 'g' 'G' . disk 'true' . maxchunksize JFR.configure . (STRING 0 ( )) o name: () . . . (STRING ) o path-to-gc-root: () (GC) . . . settings 'profile' . (BOOLEAN false) o settings: () . (',') . JAVA-HOME/lib/jfr . JDK JAVA-HOME/lib/jfr : 'default.jfc': 'profile.jfc': 'default.jfc' . . none . (STRING JAVA-HOME/lib/jfr/default.jfc) jfc. : o option: () . JAVA_HOME/bin/jfr . o event-setting: () . : #= '+' . jfc. . jfc. . 20ms. Javadoc jdk.jfr . JFR.stop [options] : : options key key=value . . options: o filename: () . %p / %t PID . . (STRING ) o name: () (STRING ) JVMTI.agent_load [arguments] (native agent) JVMTI . : arguments: o library path: JVMTI . (STRING ) o agent option: () . (STRING ) JVMTI.data_dump JVM JVMTI . : ManagementAgent.start [options] . : --- : (options) key key=value . options: o config.file: () com.sun.management.config.file (STRING ) o jmxremote.host: () com.sun.management.jmxremote.host (STRING ) o jmxremote.port: () com.sun.management.jmxremote.port (STRING ) o jmxremote.rmi.port: () com.sun.management.jmxremote.rmi.port (STRING ) o jmxremote.ssl: () com.sun.management.jmxremote.ssl (STRING ) o jmxremote.registry.ssl: () com.sun.management.jmxremote.registry.ssl (STRING ) o jmxremote.authenticate: () com.sun.management.jmxremote.authenticate (STRING ) o jmxremote.password.file: () com.sun.management.jmxremote.password.file (STRING ) o jmxremote.access.file: () com.sun.management.jmxremote.access.file (STRING ) o jmxremote.login.config: () com.sun.management.jmxremote.login.config (STRING ) o jmxremote.ssl.enabled.cipher.suites: () com.sun.management.jmxremote.ssl.enabled.cipher.suites . o jmxremote.ssl.enabled.cipher.suite: (STRING ) o jmxremote.ssl.enabled.protocols: () com.sun.management.jmxremote.ssl.enabled.protocols (STRING ) o jmxremote.ssl.need.client.auth: () com.sun.management.jmxremote.ssl.need.client.auth (STRING ) o jmxremote.ssl.config.file: () com.sun.management.jmxremote.ssl_config_file (STRING ) o jmxremote.autodiscovery: () com.sun.management.jmxremote.autodiscovery (STRING ) o jdp.port: () com.sun.management.jdp.port (INT ) o jdp.address: () com.sun.management.jdp.address (STRING ) o jdp.source_addr: () com.sun.management.jdp.source_addr (STRING ) o jdp.ttl: () com.sun.management.jdp.ttl (INT ) o jdp.pause: () com.sun.management.jdp.pause (INT ) o jdp.name: () com.sun.management.jdp.name (STRING ) ManagementAgent.start_local . : --- ManagementAgent.status . : --- ManagementAgent.stop . : --- System.native_heap_info ( ) malloc_info(3) . : System.trim_native_heap ( ) C (C-heap) . : Thread.print [options] . : --- . : (options) key key=value . options: o -e: () (BOOLEAN false) o -l: () java.util.concurrent (BOOLEAN false) VM.cds [arguments] . : --- arguments: o subcmd: static_dump dynamic_dump (STRING ) o filename: () (STRING ) filename PID JVM . java_pid1234_static.jsa java_pid5678_dynamic.jsa . filename JVM . dynamic_dump JVM JVM -XX:+RecordDynamicDumpInfo . VM.classloaders [options] . : --- . (options) key key=value . options: o show-classes: () . (BOOLEAN false) o verbose: () . (BOOLEAN false) o fold: () . (BOOLEAN true) VM.classloader_stats ClassLoader . : VM.class_hierarchy [options] [arguments] . ClassLoaderData* ClassLoader "null" (bootstrap class loader) . : --- . : (options) key key=value . options: o -i: () . (BOOLEAN false) o -s: () . . (BOOLEAN false) arguments: o classname: () . . (STRING ) VM.command_line VM . : VM.dynlibs . : VM.events [options] VM . : --- . options: : (options) key key=value . o log: () . . (STRING ) o max: () ( ). . (STRING ) VM.info JVM . : VM.log [options] // (rotate). : options: : (options) key key=value . o output: () (#) . (STRING ) o output_options: () . (STRING ) o what: () . (STRING ) o decorators: () (decorators) . 'none' . (STRING ) o disable: () . (BOOLEAN ) o list: () . (BOOLEAN ) o rotate: () . (BOOLEAN ) VM.flags [options] VM . : : (options) key key=value . options: o -all: () VM (BOOLEAN false). VM.metaspace [options] (metaspace) . : --- . : (options) key key=value . options: o basic: () ( safepoint ). (BOOLEAN false) o show-loaders: () . (BOOLEAN false) o show-classes: () show-loaders . (BOOLEAN false) o by-chunktype: () (chunk type). (BOOLEAN false) o by-spacetype: () . (BOOLEAN false) o vslist: () . (BOOLEAN false) o scale: () . : 1 KB MB GB ( ) "dynamic" . (STRING dynamic) VM.native_memory [options] . : : (options) key key=value . options: o summary: () . (BOOLEAN false) o detail: () >= 1K (callsite) . (BOOLEAN false) o baseline: () . (BOOLEAN false) o summary.diff: () . (BOOLEAN false) o detail.diff: () . (BOOLEAN false) o statistics: () . (BOOLEAN false) o scale: () KB MB GB (STRING KB) VM.print_touched_methods JVM . : --- . VM.set_flag [arguments] VM . : arguments: o flag name: (STRING ) o string value: () (STRING ) VM.stringtable [options] . : --- . : (options) key key=value . options: o -verbose: () (BOOLEAN false) VM.symboltable [options] . : --- . : (options) key key=value . options: o -verbose: () (BOOLEAN false) VM.systemdictionary . : : (options) key key=value . options: o verbose: () (BOOLEAN false). VM.system_properties . : VM.uptime [options] VM . : : (options) key key=value . options: o -date: () (BOOLEAN false) VM.version JVM . : JDK 21 2023 JCMD(1)