> For the complete documentation index, see [llms.txt](https://docs.openiam.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openiam.com/troubleshooting/performance/memoryutili.md). # Check memory utilization Finding how much memory each Java service is allowed and what it is actually using, including a heap summary from a running process. Every OpenIAM service, along with OpenSearch and Cassandra, runs as a Java process with its own memory ceiling. Two questions come up: what is each one *allowed*, and what is one of them *using*. | Symptom | Likely cause | Resolution | | ----------------------------------------------------------------------------- | --------------------------------------------------------------- | --------------------------------------------------------------------------------------------- | | A service restarts repeatedly, or logs an out-of-memory error | Its heap ceiling is too low for the load | Read the ceiling below, then [Increasing RAM](/troubleshooting/performance/increasing-ram.md) | | The host is short of memory and you need to know which service is responsible | Several services sized independently, and their ceilings add up | Read the ceilings below and compare the total against the host | ## What each service is allowed ```bash ps -ef | grep java ``` This lists the running Java processes with the arguments each was started with. The **`-Xmx` value is the heap ceiling** for that service, and the number before the timestamp is its PID. {% code overflow="wrap" expandable="true" %} ``` openiam 16649 16646 2 16:39 ? 00:05:44 /usr/local/openiam/jdk/bin/java -Dlogging.level.root=WARN -Dlogging.level.org.openiam=WARN -Dconfpath=/usr/local/openiam -jar -Xmx1024m -Djdk.tls.client.protocols=TLSv1.2 /usr/local/openiam/services/bin/auth-manager.jar openiam 16690 16687 1 16:39 ? 00:02:27 /usr/local/openiam/jdk/bin/java -Dlogging.level.root=WARN -Dlogging.level.org.openiam=WARN -Dconfpath=/usr/local/openiam -jar -Xmx256m -Djdk.tls.client.protocols=TLSv1.2 /usr/local/openiam/services/bin/device-manager.jar openiam 16733 16728 1 16:39 ? 00:03:07 /usr/local/openiam/jdk/bin/java -Dlogging.level.root=WARN -Dlogging.level.org.openiam=WARN -Dconfpath=/usr/local/openiam -jar -Xmx512m -Djdk.tls.client.protocols=TLSv1.2 /usr/local/openiam/services/bin/email-manager.jar openiam 16813 16774 1 16:39 ? 00:04:17 /usr/local/openiam/jdk/bin/java -Dlogging.level.root=WARN -Dlogging.level.org.openiam=WARN -Dconfpath=/usr/local/openiam -jar -Xmx2048m -Djdk.tls.client.protocols=TLSv1.2 /usr/local/openiam/services/bin/openiam-esb.jar openiam 16820 16811 1 16:39 ? 00:02:44 /usr/local/openiam/jdk/bin/java -Dlogging.level.root=WARN -Dlogging.level.org.openiam=WARN -Dconfpath=/usr/local/openiam -jar -Xmx512m -Djdk.tls.client.protocols=TLSv1.2 /usr/local/openiam/services/bin/groovy-manager.jar openiam 16879 16877 2 16:39 ? 00:04:59 /usr/local/openiam/jdk/bin/java -Dlogging.level.root=WARN -Dlogging.level.org.openiam=WARN -Dconfpath=/usr/local/openiam -jar -Xmx512m -Djdk.tls.client.protocols=TLSv1.2 /usr/local/openiam/services/bin/idm.jar ``` {% endcode %} The ceilings differ per service and are set at installation. The listing above is one deployment's — read your own rather than assuming these numbers. ## What one service is actually using Sending a running JVM a `QUIT` signal makes it write a thread dump and a heap summary to its log: ```bash kill -3 ``` {% hint style="info" %} **Despite the name, this does not stop the service.** `kill -3` sends `SIGQUIT`, which the JVM handles by dumping its state and carrying on. It is safe on a live deployment. {% endhint %} The dump goes to that service's log in `/usr/local/openiam/logs`, so read it there: {% code overflow="wrap" expandable="true" %} ``` tail auth-manager.log Output: JNI global refs: 31, weak refs: 0 Heap garbage-first heap total 512000K, used 215965K [0x00000000c0000000, 0x0000000100000000) region size 1024K, 138 young (141312K), 10 survivors (10240K) Metaspace used 129663K, capacity 132186K, committed 133768K, reserved 1167360K class space used 15396K, capacity 16406K, committed 16972K, reserved 1048576K ``` {% endcode %} `total` against `used` on the heap line is the reading you want. A heap sitting close to its total under normal load is the service to raise. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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