JCMD(1) JDK Commands JCMD(1) (NAME) jcmd - (JVM) (SYNOPSIS) jcmd [pid | main-class] command... | PerfCounter.print | -f filename jcmd [-l] jcmd -h pid jcmd (PID) . main-class jcmd (main class) . command command jcmd JVM . jcmd help (jcmd pid help) pid . Perfcounter.print (performance counters) . -f filename filename . -l docker . JVM docker ps PID . : jcmd jcmd -l . -h jcmd . (DESCRIPTION) jcmd JVM . JVM JVM . . . : jcmd pid help command (' "). (\) . ( ). (pid) (main-class) jcmd . 0 ..SH " JCMD (COMMANDS FOR JCMD)" command jcmd JVM . jcmd help (jcmd pid help) pid . pid 0 . . docker ( -l). jcmd . key key=value . name=value. : help [options] [arguments] . : o command name: (STRING ) : key key=value . : o -all: () (BOOLEAN false) . AOT.end_recording AOT () -XX:AOTConfiguration / -XX:AOTCacheOutput . : : JVM -XX:AOTMode=record -XX:AOTCacheOutput= AOT . AOT AOT AOT . Compiler.CodeHeap_Analytics [function] [granularity] CodeHeap : : code heap . CodeCache_lock . : o function: () (aggregate UsedSpace FreeSpace MethodCount MethodSpace MethodAge MethodNames discard (STRING all) o granularity: () - -> (INT 4096) Compiler.codecache code cache . : Compiler.codelist code cache . : Compiler.directives_add arguments . : : o filename: (STRING ) Compiler.directives_clear . : Compiler.directives_print . : Compiler.directives_remove . : Compiler.memory [options] : : : key key=value . : o -H: () (BOOLEAN false) o -s: () (MEMORY SIZE 0) Compiler.perfmap [arguments] ( ) map perf . : : o filename: () map. %p PID JVM . (FILE "/tmp/perf-%p.map") Compiler.queue . : GC.class_histogram [options] Java heap . : --- Java heap . : key key=value . : o -all: () (BOOLEAN false) o -parallel: () heap. 0 () . 1 ( ). . (INT 0) GC.finalizer_info . : GC.heap_dump [options] filename HPROF Java heap . : --- Java heap . -all GC . : key key=value . : o -all: () (BOOLEAN false) o -gz: () heap gzip . 1 () 9 . (INT 1).IP o 2 -overwrite: () (BOOLEAN, false) o -parallel: () . (VM) . (INT, 1) : o filename: . %p PID JVM . (FILE ) GC.heap_info . : GC.run java.lang.System.gc() . : --- . GC.run_finalization java.lang.System.runFinalization() . : --- . JFR.check [options] (flight recording) : : key key=value . . : o name: () . (STRING ) o verbose: () (BOOLEAN, false) JFR.configure [options] (flight recording) : : key key=value . . : o dumppath: () (crash) . (STRING ) o globalbuffercount: () . : memorysize . JFR . (STRING memorysize ) o globalbuffersize: () . : memorysize . JFR . (STRING memorysize ) o maxchunksize: () (chunk) : '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] : : key key=value . . . : 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 JVM . (FILE ) o maxage: () . (INTEGER 's' 'm' 'h' ) o maxsize: () : 'm' 'M' 'g' 'G' . (STRING ).IP o 2 name: () . (dump) . (STRING ) o path-to-gc-roots: () (GC) . . . (BOOLEAN false) JFR.start [options] (flight recording) : : options key key=value . . options: o delay: () (INTEGER 's' 'm' 'h' 0s) o disk: () (BOOLEAN true) o dumponexit: () (JVM). 'true' filename . (PID) . ( : id-1-2019_12_12_10_41.jfr) (BOOLEAN false) o duration: () . 0s (INTEGER 's' 'm' 'h' 0s) o filename: () flight recording . PID . PID . %p %t PID JVM . (FILE ) 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-roots: () (GC) . . . settings 'profile' (stack trace) . (BOOLEAN false) o settings: () . (',') . JAVA-HOME/lib/jfr . JDK JAVA-HOME/lib/jfr : 'default.jfc': (overhead) 'profile.jfc': 'default.jfc' . . none . (STRING JAVA-HOME/lib/jfr/default.jfc) .jfc : o option: () . JAVA_HOME/bin/jfr . o event-setting: () . : #= '+' . .jfc (whitespace) . .jfc . 20ms . Javadoc jdk.jfr . JFR.stop [options] (flight recording) : : options key key=value . . options: o filename: () . %p %t PID JVM . . (FILE ) o name: () (STRING ) JFR.view [options] . : : options key key=value . . options: o cell-height: () . (INT ) o maxage: () . (INT 's' 'm' 'h' 10m ) o maxsize: () : 'm' 'M' 'g' 'G' . (STRING 32MB ) o truncate: () . (INT ) o verbose: () (query) . (BOOLEAN false ) o width: () (). (INT ) arguments:.IP o 2 view: (view) . help JFR.view . (STRING ) view . JFR.view types . JFR.view all-views . JFR.view all-events . JVMTI.agent_load [arguments] (native agent) JVMTI . : arguments: o library path: JVMTI . (STRING ) o agent option: () . (STRING ) JVMTI.data_dump JVM (data-dump) JVMTI. : ManagementAgent.start [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.acce ss.file (STRING ) o jmxremote.login.config: () com.sun.management.jmxremote.log in.config (STRING ) o jmxremote.ssl.enabled.cipher.suites: () com.sun.management . o jmxremote.ssl.enabled.cipher.suite: (STRING ) o jmxremote.ssl.enabled.protocols: () com.sun.management.jmxr emote.ssl.enabled.protocols (STRING ) o jmxremote.ssl.need.client.auth: () com.sun.management.jmxre mote.need.client.auth (STRING ) o jmxremote.ssl.config.file: () com.sun.management.jmxremote. ssl_config_file (STRING ) o jmxremote.autodiscovery: () com.sun.management.jmxremote.au todiscovery (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.dump_map [options] ( ) . : : key key=value . options: o -H: () (BOOLEAN false) o -F: () . %p PID JVM . (FILE "vm_memory_map_%p.txt") System.map [options] ( ) VM . : : key key=value . options: o -H: () (BOOLEAN false) System.native_heap_info ( ) (native heap) malloc_info(3) . "Error: " . : System.trim_native_heap ( ) C-heap . : Thread.dump_to_file [options] filepath (threads) (stack trace) JSON. : : . : key key=value . options:.IP o 2 -overwrite: () (BOOLEAN false) o -format: () ("plain" "json") (STRING plain) : o filepath: . %p PID JVM . (FILE ) Thread.print [] . Thread.dump_to_file . : --- . : key key=value . : o -e: () (BOOLEAN false) o -l: () java.util.concurrent (BOOLEAN false) Thread.vthread_scheduler . : Thread.vthread_pollers I/O / . : VM.cds [] . : --- : o subcmd: static_dump dynamic_dump (STRING ) o filename: () . %p PID JVM . (FILE "java_pid%p_.jsa") dynamic_dump JVM JVM -XX:+RecordDynamicDumpInfo . VM.class_hierarchy [] [] . ClassLoaderData* ClassLoader (bootstrap class loader) "null" . : --- . : key key=value . : o -i: () . (BOOLEAN false) o -s: () classname . . (BOOLEAN false) : o classname: () . . (STRING ) VM.classes [] : : . key key=value . : o -verbose: () . : F = finalize f = final W = C = @Contended R = S = (BOOLEAN false) VM.classloader_stats ClassLoader. : VM.classloaders [] classloader . : --- . key key=value . : o show-classes: () . (BOOLEAN false) o verbose: () . (BOOLEAN false) o fold: () . (BOOLEAN true) VM.command_line VM . : VM.dynlibs . : VM.events [] VM : --- . : : key key=value . o log: () . . (STRING ) o max: () ( ). . (INT 0) VM.flags [] VM . : : key key=value . : o -all: () VM (BOOLEAN false). VM.info JVM. : VM.log [] // . : : : key key=value . o output: () (#) . (STRING ) o output_options: () . (STRING ) o what: () . (STRING ) o decorators: () . 'none' . (STRING ) o disable: () . (BOOLEAN ) o list: () . (BOOLEAN ) o rotate: () . (BOOLEAN ) VM.metaspace [] metaspace. : --- . : key key=value . : o basic: () ( safepoint ). (BOOLEAN false) o show-loaders: () (class loader). (BOOLEAN false) o show-classes: () show-loaders . (BOOLEAN false) o by-chunktype: () chunk. (BOOLEAN false) o by-spacetype: () . (BOOLEAN false) o vslist: () (virtual space) . (BOOLEAN false) o chunkfreelist: () chunk (ChunkManager). (BOOLEAN false) o scale: () . : 1 KB MB GB ( ) "dynamic" . (STRING dynamic) VM.native_memory [] (native memory). : : key key=value . : o summary: () (runtime) (committed) . (BOOLEAN false) o detail: () >= 1K (callsite) . (BOOLEAN false) o baseline: () (baseline) . (BOOLEAN false) o summary.diff: () . (BOOLEAN false) o detail.diff: () . (BOOLEAN false) o statistics: () (tracker) . (BOOLEAN false) o scale: () KB MB GB (STRING KB) VM.set_flag [] . : : o flag name: (STRING ) o string value: () (STRING ) VM.stringtable [] (string table). : --- . : key key=value . : o -verbose: () (BOOLEAN false) VM.symboltable [] (symbol table). : --- . : key key=value . : o -verbose: () (BOOLEAN false) VM.system_properties (system properties). : VM.systemdictionary (bucket length). : : key key=value . : o verbose: () (BOOLEAN false). VM.uptime [] (uptime). : : key key=value . :.IP o 2 -date: () (BOOLEAN false) VM.version JVM . : JDK 26.0.2.1 2026 JCMD(1)