How to record JFR (Java Flight Recorder) and output a dump file

We will introduce how to record JFR (Java Flight Recorder) and output a dump file. Here, the state of ** Eclipse GlassFish 5.1.0 ** is recorded.

environment

• OS：CentOS Linux release 7.7.1908
• jdk1.8
• GlassFish 5.1.0

[glassfish@CENTOS7 ~]$ cat /etc/redhat-release
CentOS Linux release 7.7.1908 (Core)
[glassfish@CENTOS7 ~]$

[glassfish@CENTOS7 ~]$ java -version
java version "1.8.0_241"
Java(TM) SE Runtime Environment (build 1.8.0_241-b07)
Java HotSpot(TM) 64-Bit Server VM (build 25.241-b07, mixed mode)
[glassfish@CENTOS7 ~]$

[glassfish@CENTOS7 ~]$ /opt/glassfish5/glassfish/bin/asadmin version
Version string could not be obtained from Server [localhost:4848].
(Turn debugging on e.g. by setting AS_DEBUG=true in your environment, to see the details.)
Using locally retrieved version string from version class.
Version = GlassFish Server Open Source Edition  5.1.0  (build default-private)
Command version executed successfully.
[glassfish@CENTOS7 ~]$

For ** GlassFish 5.1.0 ** installation, see the previous post How to install Eclipse GlassFish 5.1.0 on CentOS 7. Please give me.

1. Setting JVM options when starting Glassfish

Add the following to the JVM options when starting Glassfish.

• -XX:+UnlockCommercialFeatures
• -XX:+FlightRecorder
• -XX:FlightRecorderOptions=<..>

Specifically, "domain / configs / java-config" of domain.xml under" / opt / glassfish5 / glassfish / domains / domain1 / config" (java-config tag in the configs tag in the domain tag) Add the following 3 lines to (inside).

/opt/glassfish5/glassfish/domains/domain1/config/domain.Add to xml

<jvm-options>-XX:+UnlockCommercialFeatures</jvm-options>
<jvm-options>-XX:+FlightRecorder</jvm-options>
<jvm-options>-XX:FlightRecorderOptions=defaultrecording=true,disk=true,repository=/var/log/jvm/repositories,maxsize=2048m,maxage=25h,dumponexit=true,dumponexitpath=/var/log/jvm/dump.jfr</jvm-options>

• For details on setting FlightRecorderOptions, refer to Java Page.

Here, / var / log / jvm is used as the temporary directory, so create a jvm directory under / var / log, and the glassfish user can create files and files under / var / log / jvm. Make sure you can create the directory.

Execution result

[glassfish@CENTOS7 ~]$ su
password:
[root@CENTOS7 glassfish]# cd /var/log
[root@CENTOS7 log]#
[root@CENTOS7 log]# mkdir jvm
[root@CENTOS7 log]# chown glassfish:glassfish jvm
[root@CENTOS7 log]# exit
exit
[glassfish@CENTOS7 ~]$

2. Start Glassfish

Start Glassfish with the following command.

/opt/glassfish5/glassfish/bin/asadmin start-domain domain1

Execution result

[glassfish@CENTOS7 config]$ /opt/glassfish5/glassfish/bin/asadmin start-domain domain1
Waiting for domain1 to start ......
Successfully started the domain : domain1
domain  Location: /opt/glassfish5/glassfish/domains/domain1
Log File: /opt/glassfish5/glassfish/domains/domain1/logs/server.log
Admin Port: 4848
Command start-domain executed successfully.
[glassfish@CENTOS7 config]$

3. Output of JFR dump file

First, check the process ID of glassfish with the following command.

ps -ef | grep glassfish | grep -v grep

Execution result

[glassfish@CENTOS7 config]$ ps -ef | grep glassfish | grep -v grep
glassfi+ 26302     1  5 19:54 pts/0    00:00:16 /usr/java/jdk1.8.0_241-amd64/bin/java -cp /opt/glassfish5/glassfish/modules/glassfish.jar -XX:+UnlockCommercialFeatures -XX:+UnlockDiagnosticVMOptions -XX:NewRatio=2 -XX:FlightRecorderOptions=defaultrecording=true,disk=true,repository=/var/log/jvm/repositories,maxsize=2048m,maxage=25h,dumponexit=true,dumponexitpath=/var/log/jvm/dump.jfr -XX:+FlightRecorder -XX:MaxPermSize=192m -Xmx512m -javaagent:/opt/glassfish5/glassfish/lib/monitor/flashlight-agent.jar -client -Djavax.xml.accessExternalSchema=all -Djavax.net.ssl.trustStore=/opt/glassfish5/glassfish/domains/domain1/config/cacerts.jks -Djdk.tls.rejectClientInitiatedRenegotiation=true -Djdk.corba.allowOutputStreamSubclass=true -Dfelix.fileinstall.dir=/opt/glassfish5/glassfish/modules/autostart/ -Dorg.glassfish.additionalOSGiBundlesToStart=org.apache.felix.shell,org.apache.felix.gogo.runtime,org.apache.felix.gogo.shell,org.apache.felix.gogo.command,org.apache.felix.shell.remote,org.apache.felix.fileinstall -Dcom.sun.aas.installRoot=/opt/glassfish5/glassfish -Dfelix.fileinstall.poll=5000 -Djava.endorsed.dirs=/opt/glassfish5/glassfish/modules/endorsed:/opt/glassfish5/glassfish/lib/endorsed -Djava.security.policy=/opt/glassfish5/glassfish/domains/domain1/config/server.policy -Dosgi.shell.telnet.maxconn=1 -Dfelix.fileinstall.bundles.startTransient=true -Dcom.sun.enterprise.config.config_environment_factory_class=com.sun.enterprise.config.serverbeans.AppserverConfigEnvironmentFactory -Dfelix.fileinstall.log.level=2 -Djavax.net.ssl.keyStore=/opt/glassfish5/glassfish/domains/domain1/config/keystore.jks -Djava.security.auth.login.config=/opt/glassfish5/glassfish/domains/domain1/config/login.conf -Dfelix.fileinstall.disableConfigSave=false -Dfelix.fileinstall.bundles.new.start=true -Dcom.sun.aas.instanceRoot=/opt/glassfish5/glassfish/domains/domain1 -Dosgi.shell.telnet.port=6666 -Dgosh.args=--nointeractive -Dcom.sun.enterprise.security.httpsOutboundKeyAlias=s1as -Dosgi.shell.telnet.ip=127.0.0.1 -DANTLR_USE_DIRECT_CLASS_LOADING=true -Djava.awt.headless=true -Dcom.ctc.wstx.returnNullForDefaultNamespace=true -Djava.ext.dirs=/usr/java/jdk1.8.0_241-amd64/lib/ext:/usr/java/jdk1.8.0_241-amd64/jre/lib/ext:/opt/glassfish5/glassfish/domains/domain1/lib/ext -Djdbc.drivers=org.apache.derby.jdbc.ClientDriver -Djava.library.path=/opt/glassfish5/glassfish/lib:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib com.sun.enterprise.glassfish.bootstrap.ASMain -upgrade false -domaindir /opt/glassfish5/glassfish/domains/domain1 -read-stdin true -asadmin-args --host,,,localhost,,,--port,,,4848,,,--secure=false,,,--terse=false,,,--echo=false,,,--interactive=true,,,start-domain,,,--verbose=false,,,--watchdog=false,,,--debug=false,,,--domaindir,,,/opt/glassfish5/glassfish/domains,,,domain1 -domainname domain1 -instancename server -type DAS -verbose false -asadmin-classpath /opt/glassfish5/glassfish/lib/client/appserver-cli.jar -debug false -asadmin-classname com.sun.enterprise.admin.cli.AdminMain
[glassfish@CENTOS7 config]$

You can see that the process ID is 26302.

Output the JFR (Java Flight Recorder) record to a dump file with the following command.

jcmd <process ID> JFR.dump recording = 0 filename = <path of output dump file>

Execution result

[glassfish@CENTOS7 ~]$ jcmd 26302 JFR.dump recording=0 filename=/home/glassfish/perf/test_$(date "+%Y%m%d_%H%M%S").jfr
26302:
Dumped recording 0, 2.5 MB written to:

/home/glassfish/perf/test_20200726_200546.jfr
[glassfish@CENTOS7 ~]$

Check the output dump file.

Execution result

[glassfish@CENTOS7 ~]$ cd /home/glassfish/perf
[glassfish@CENTOS7 perf]$ ls -l
2600 in total
-rw-rw-r--.1 glassfish glassfish 2660207 July 26 20:05 test_20200726_200546.jfr
[glassfish@CENTOS7 perf]$

3. Refer to the dump file (jfr file) output by "jmc.exe"

Transfer the output jfr dump file (test_20200726_200546.jfr) to the Windows PC on which jdk1.8 is installed.

Start "jmc.exe" (Java Mission Contorol) under " C: \ Program Files \ Java \ jdk1.8.0_231 \ bin ".

Open the jfr dump file (test_20200726_200546.jfr) output by selecting "File"-"Open File" from the menu.

You can refer to the jfr dump file output by "jmc.exe" (Java Mission Contorol).

reference

Java Platform, Standard Edition Tools Reference