JVM Command: JInfo

In linux, typically ‘top’ is used to view the details of running processes. Often it is required that you may want to see full process command instead of just the process name. Using option ‘c’ in top, you can see the full command almost always.

However,  typically OS has limits the length of full command  4096 characters! So if your process has longer full command, specaially applicable for java processes; you wouldn’t see it. Neither in ‘top’ nor in ‘ps –ef | grep <pid>’.

Good way to see exact details of the java process is to use ‘jinfo’. Following is the example of such a long command.

<JAVA_HOME>/bin/jinfo <process-id>

Example:

[root@home ~]$ /usr/java/jdk1.6.0_45/bin/jinfo 55761

Attaching to process ID 55761, please wait...

Debugger attached successfully.

Server compiler detected.

JVM version is 20.45-b01

Java System Properties:

java.runtime.name = Java(TM) SE Runtime Environment

sun.boot.library.path = /usr/java/jdk1.6.0_45/jre/lib/amd64

java.vm.version = 20.45-b01

java.vm.vendor = Sun Microsystems Inc.

java.vendor.url = http://java.sun.com/

storm.home = /opt/storm-0.8.2

path.separator = :

java.vm.name = Java HotSpot(TM) 64-Bit Server VM

file.encoding.pkg = sun.io

sun.java.launcher = SUN_STANDARD

user.country = US

sun.os.patch.level = unknown

java.vm.specification.name = Java Virtual Machine Specification

user.dir = /home/gse

java.runtime.version = 1.6.0_45-b06

java.awt.graphicsenv = sun.awt.X11GraphicsEnvironment

java.endorsed.dirs = /usr/java/jdk1.6.0_45/jre/lib/endorsed

os.arch = amd64

java.io.tmpdir = /tmp

line.separator =

java.vm.specification.vendor = Sun Microsystems Inc.

os.name = Linux

log4j.configuration = storm.log.properties

sun.jnu.encoding = UTF-8

java.library.path = /usr/local/lib:/opt/local/lib:/usr/lib

java.specification.name = Java Platform API Specification

java.class.version = 50.0

sun.management.compiler = HotSpot 64-Bit Tiered Compilers

os.version = 2.6.32-358.11.1.el6.x86_64

user.home = /root

user.timezone = GMT

java.awt.printerjob = sun.print.PSPrinterJob

file.encoding = UTF-8

java.specification.version = 1.6

java.class.path = /opt/storm-0.8.2/storm-0.8.2.jar:/opt/storm-0.8.2/lib/jgrapht-0.8.3.jar:/opt/storm-0.8.2/lib/log4j-1.2.16.jar:/opt/storm-0.8.2/lib/kryo-2.17.jar:/opt/storm-0.8.2/lib/guava-13.0.jar:/opt/storm-0.8.2/lib/disruptor-2.10.1.jar:/opt/storm-0.8.2/lib/objenesis-1.2.jar:/opt/storm-0.8.2/lib/junit-3.8.1.jar:/opt/storm-0.8.2/lib/joda-time-2.0.jar:/opt/storm-0.8.2/lib/commons-exec-1.1.jar:/opt/storm-0.8.2/lib/tools.logging-0.2.3.jar:/opt/storm-0.8.2/lib/curator-client-1.0.1.jar:/opt/storm-0.8.2/lib/zookeeper-3.3.3.jar:/opt/storm-0.8.2/lib/ring-core-1.1.5.jar:/opt/storm-0.8.2/lib/commons-fileupload-1.2.1.jar:/opt/storm-0.8.2/lib/tools.macro-0.1.0.jar:/opt/storm-0.8.2/lib/carbonite-1.5.0.jar:/opt/storm-0.8.2/lib/core.incubator-0.1.0.jar:/opt/storm-0.8.2/lib/commons-codec-1.4.jar:/opt/storm-0.8.2/lib/ring-jetty-adapter-0.3.11.jar:/opt/storm-0.8.2/lib/minlog-1.2.jar:/opt/storm-0.8.2/lib/clojure-1.4.0.jar:/opt/storm-0.8.2/lib/clj-time-0.4.1.jar:/opt/storm-0.8.2/lib/commons-logging-1.1.1.jar:/opt/storm-0.8.2/lib/libthrift7-0.7.0.jar:/opt/storm-0.8.2/lib/clout-1.0.1.jar:/opt/storm-0.8.2/lib/jline-0.9.94.jar:/opt/storm-0.8.2/lib/slf4j-log4j12-1.5.8.jar:/opt/storm-0.8.2/lib/jzmq-2.1.0.jar:/opt/storm-0.8.2/lib/servlet-api-2.5.jar:/opt/storm-0.8.2/lib/commons-io-1.4.jar:/opt/storm-0.8.2/lib/httpcore-4.1.jar:/opt/storm-0.8.2/lib/jetty-util-6.1.26.jar:/opt/storm-0.8.2/lib/httpclient-4.1.1.jar:/opt/storm-0.8.2/lib/commons-lang-2.5.jar:/opt/storm-0.8.2/lib/math.numeric-tower-0.0.1.jar:/opt/storm-0.8.2/lib/snakeyaml-1.9.jar:/opt/storm-0.8.2/lib/json-simple-1.1.jar:/opt/storm-0.8.2/lib/compojure-1.1.3.jar:/opt/storm-0.8.2/lib/servlet-api-2.5-20081211.jar:/opt/storm-0.8.2/lib/hiccup-0.3.6.jar:/opt/storm-0.8.2/lib/jetty-6.1.26.jar:/opt/storm-0.8.2/lib/curator-framework-1.0.1.jar:/opt/storm-0.8.2/lib/ring-servlet-0.3.11.jar:/opt/storm-0.8.2/lib/asm-4.0.jar:/opt/storm-0.8.2/lib/reflectasm-1.07-shaded.jar:/opt/storm-0.8.2/lib/tools.cli-0.2.2.jar:/opt/storm-0.8.2/lib/slf4j-api-1.5.8.jar:/opt/storm-0.8.2/log4j:/opt/storm-0.8.2/conf

user.name = root

java.vm.specification.version = 1.0

sun.java.command = backtype.storm.daemon.worker xyz56-36-1406612749 d39a4666-52a2-4099-8ca5-ee9aac670783 6702 d6db40f4-032b-443b-9c7e-b0ddc6b80b31

java.home = /usr/java/jdk1.6.0_45/jre

sun.arch.data.model = 64

user.language = en

java.specification.vendor = Sun Microsystems Inc.

java.vm.info = mixed mode

java.version = 1.6.0_45

java.ext.dirs = /usr/java/jdk1.6.0_45/jre/lib/ext:/usr/java/packages/lib/ext

logfile.name = worker-6702.log

sun.boot.class.path = /usr/java/jdk1.6.0_45/jre/lib/resources.jar:/usr/java/jdk1.6.0_45/jre/lib/rt.jar:/usr/java/jdk1.6.0_45/jre/lib/sunrsasign.jar:/usr/java/jdk1.6.0_45/jre/lib/jsse.jar:/usr/java/jdk1.6.0_45/jre/lib/jce.jar:/usr/java/jdk1.6.0_45/jre/lib/charsets.jar:/usr/java/jdk1.6.0_45/jre/lib/modules/jdk.boot.jar:/usr/java/jdk1.6.0_45/jre/classes

java.vendor = Sun Microsystems Inc.

file.separator = /

java.vendor.url.bug = http://java.sun.com/cgi-bin/bugreport.cgi

sun.io.unicode.encoding = UnicodeLittle

sun.cpu.endian = little

sun.cpu.isalist =

VM Flags:

-Xmx768m -Djava.library.path=/usr/local/lib:/opt/local/lib:/usr/lib -Dlogfile.name=worker-6702.log -Dstorm.home=/opt/storm-0.8.2 -Dlog4j.configuration=storm.log.properties

Usage:
    jinfo [option] <pid>
        (to connect to running process)
    jinfo [option] <executable <core>
        (to connect to a core file)
    jinfo [option] [server_id@]<remote server IP or hostname>
        (to connect to remote debug server)

where <option> is one of:
    -flag <name>         to print the value of the named VM flag
    -flag [+|-]<name>    to enable or disable the named VM flag
    -flag <name>=<value> to set the named VM flag to the given value
    -flags               to print VM flags
    -sysprops            to print Java system properties
    <no option>          to print both of the above
    -h | -help           to print this help message