Tune JVM settings

This section gives some initial guidance on configuring the JVM for running AM when the deployment has a dedicated CTS token store, and AM is configured to use server-side sessions.

These settings provide a strong foundation to the JVM before a more detailed garbage collection tuning exercise, or as best practice configuration for production:

Heap size settings
JVM parameters	Suggested value	Description
`-Xms` & `-Xmx`	At least 1 GB (2 GB with embedded DS), in production environments at least 2 GB to 3 GB. This setting depends on the available physical memory, and on whether a 32- or 64-bit JVM is used.
`-XX:MetaspaceSize` & `-XX:MaxMetaspaceSize`	Set both to 256 MB	Controls the size of the metaspace in the JVM
`-Dsun.net.client.defaultReadTimeout`	60000	Controls the read timeout in the Java HTTP client implementation. This applies only to the Sun/Oracle HotSpot JVM.
`-Dsun.net.client.defaultConnectTimeout`	High setting: 30000 (30 seconds)	Controls the connect timeout in the Java HTTP client implementation When you have hundreds of incoming requests per second, reduce this value to avoid a huge connection queue. This applies only to the Sun/Oracle HotSpot JVM.

Security settings
JVM parameters	Suggested value	Description
`-Dhttps.protocols`	`TLSv1.2`	Controls the protocols used for outbound HTTPS connections from AM. Specify one or more of the following values, separated by commas: TLSv1.2 TLSv1.3 This setting applies only to Sun/Oracle Java environments.
`-Dorg.forgerock.openam.ldap.secure.protocol.version`	`TLSv1.2`	Controls the protocol AM uses to connect to affected external resources. Specify one or more of the following values, separated by commas: TLSv1.2 TLSv1.3 This setting overrides the default server value. For details, refer to advanced properties.

Garbage collection settings
JVM parameters	Suggested value	Description
`-verbose:gc`		Verbose garbage collection reporting.
`-Xlog:gc*`	`-Xlog:gc=info:file=$CATALINA_HOME/logs/gc-info.log`	Logs detailed information about garbage collection. When using the `-Xlog:gc` option, you can also specify the level, and output file.
`-XX:+HeapDumpOnOutOfMemoryError`		Out of Memory errors generate a heap dump automatically.
`-XX:HeapDumpPath`	`$CATALINA_HOME/logs/heapdump.hprof`	Location of the heap dump.
`-XX:+PrintClassHistogram`		Prints a heap histogram when the JVM receives a SIGTERM signal.

Java 17-specific settings
Module flag	Suggested value	Description
`--add-opens`	`java.xml/com.sun.org.apache.xerces.internal.dom=ALL-UNNAMED`	When running AM with JRE 17, SAML Artifact flows (or any flows that use Xerces SOAP libraries) can fail with the following error: `Caused by: java.lang.IllegalAccessError: superclass access check failed: class com.sun.xml.messaging.saaj.soap.SOAPDocumentImpl (in unnamed module @0x774ca796) cannot access class com.sun.org.apache.xerces.internal.dom.DocumentImpl (in module java.xml) because module java.xml does not export com.sun.org.apache.xerces.internal.dom to unnamed module @0x774ca796` Set this module flag to avoid this error.

Access Management 7.3.1

Tune JVM settings