How do I enable Garbage Collector (GC) Logging for DS?

Overview

Unified JVM Logging is used for GC logging in Java® 11. The logging options available in Java 8 and earlier will not work with Java 11. See JEP 158: Unified JVM Logging for further information.

This article provides details on enabling GC logging according to which version of Java you are using:

• Java 11
• Java 8 and earlier

You can use the Universal GC Log Analyzer to analyze your GC log. This is a third-party website that we suggest can be used for analysis but is not supported by ForgeRock.

Enabling GC Logging (Java 11)

On Unix® and Linux® systems:

You can enable GC logging as follows:

1. Locate and edit your /path/to/ds/config/java.properties file for the DS instance for which you want to enable GC Logging.
2. Append the required options to the entry start-ds.java-args=. For example: start-ds.java-args=-server -Xlog:gc=debug:file=/tmp/gc.log:time,uptime,level,tags:filecount=5,filesize=100mThere are many options available as detailed in JEP 158: Unified JVM Logging but this is a good starting point.
3. Restart the DS server.

Once the server has successfully restarted, there should be a GC log file located in the directory specified in the file: option. 

On Microsoft® Windows® systems:

You can enable GC logging as follows:

1. Locate and edit your \path\to\ds\config\java.properties file for the DS instance for which you want to enable GC Logging.
2. Append the required options to the entry start-ds.java-args=. For example: start-ds.java-args=-server -Xlog:gc=debug:file=C:\tmp\gc.log:time,uptime,level,tags:filecount=5,filesize=100mThere are many options available as detailed in JEP 158: Unified JVM Logging but this is a good starting point.
3. Restart the DS server.

Once the server has successfully restarted, there should be a GC log file located in the directory specified in the file: option.

Enabling GC Logging (Java 8 and earlier)

On Unix and Linux systems:

You can enable GC logging as follows:

1. Locate and edit your /path/to/ds/config/java.properties file for the DS instance for which you want to enable GC Logging.
2. Append the following options to the entry start-ds.java-args= -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintGCCause -Xloggc:[filename]replacing [filename] with the path to the file that you would like to create to store the log file. For example: start-ds.java-args=-server -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintGCCause -Xloggc:/tmp/gc.log
3. Restart the DS server.

Once the server has successfully restarted, there should be a GC log file located in the directory specified in the -Xloggc: option.

On Microsoft Windows systems:

You can enable GC logging as follows:

1. Locate and edit your \path\to\ds\config\java.properties file for the DS instance for which you want to enable GC Logging.
2. Append the following options to the entry start-ds.java-args= -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintGCCause -Xloggc:[filename]replacing [filename] with the path to the file that you would like to create to store the log file. For example: start-ds.java-args=-server -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintGCCause -Xloggc:C:\tmp\gc.log
3. Restart the DS server.

Once the server has successfully restarted, there should be a GC log file located in the directory specified in the -Xloggc: option.

See Also

Best practice for JVM Tuning with G1 GC

Best practice for JVM Tuning with CMS GC

How do I tune DS (All versions) process sizes: JVM heap and database cache?

How do I collect JVM data for troubleshooting DS (All versions)?

FAQ: DS performance and tuning

Java Settings

Related Training

ForgeRock Directory Services Core Concepts (DS-400) 

Related Issue Tracker IDs

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