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A Cloud Guru

Creating Java Heap Dumps for JBoss EAP

While the JBoss Enterprise Application Platform makes managing our Java applications more effective, there are still some troubleshooting tactics for Java applications that we should be aware of. Our applications can be memory-intensive, and in instances of poor performance, we’ll often need to take and analyze a Java heap dump to discover the root cause of our memory issues.

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Path Info

Level

Beginner

Duration

15m

Published

Jan 24, 2020

Challenge

Create Heap Dump
1. Find the process ID for Java:
```
pgrep java
```
1. Create a heap dump:
```
sudo jcmd [Your PID] GC.heap_dump -all=true heapcheck.hprof
```
1. Check that the heap dump has been created in /opt/jboss-eap:
```
ls /opt/jboss-eap
```
Challenge

Configure Automatic Heap Dump Creation
1. Create a directory to store heap dumps and move the heapcheck.hpof file to it:
```
sudo mkdir /opt/jboss-eap/heapdumps
sudo mv /opt/jboss-eap/heapcheck.hprof /opt/jboss-eap/heapdumps/
```
1. Configure JBoss to automatically generate a heap dump when there is an out-of-memory error; ensure it is saved to the newly-created directory:
```
export JAVA_OPTS="-XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/opt/jboss-eap/heapdumps/oomdump.hprof"
```
1. Restart JBoss:
```
sudo systemctl restart jboss-eap-rhel
```

Challenge

Parse the Heap Dump

Download the Eclipse Memory Analyzer:

cd
curl -O http://mirror.math.princeton.edu/pub/eclipse/mat/1.13.0/rcp/MemoryAnalyzer-1.13.0.20220615-linux.gtk.x86_64.zip

Extract the contents of the download:

unzip MemoryAnalyzer-1.13.0.20220615-linux.gtk.x86_64.zip

Run the script to parse the heap dump:

cd mat
sudo ./ParseHeapDump.sh /opt/jboss-eap/heapdumps/heapcheck.hprof

Confirm the heap dump has been parsed:

ls /opt/jboss-eap/heapdumps/

Author

A Cloud Guru

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

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