HeapLib a tool/library for analyzing JVM heap dumps. HeapLib is using modified heap parser from Apache NetBeans (same library is used by VisualVM).
Main driver for this project was a need in automated analyzing of heap dump on remote servers.
In addition for original Heap class implementation from NetBeans library this project has an alteranative which:
- Works with heap dump file without any additional on disk files
- Process GZip compressed heap dump files directly
- Cannot calculate retained size or walk object references in backward direction
Besides an API, you can use executable jar for console to execute OQL/JavaScript.
HeapLib is a library you can use from Java code.
You can find few examples in hprof-heap/src/test/java/org/gridkit/jvmtool/heapdump/example/
path formatted as JUnit tests.
You can use executable jar to execute OQL/JavaScript scripts from console.
To get executable java build project with mvn clean package. Executable jar would be placed under name heap-cli/target/heap-cli-0.1-SNAPSHOT.jar.
Below few commands support by executable:
java -jar heap-cli-*.jar --commandsprint list of supported commandjava -jar heap-cli-*.jar histo -d dump.hprofproduce class histogram from pathjava -jar heap-cli-*.jar exec --noindex -d dump.hprof -j script.oqlexecute script on heap dump open in diskless mode (no on-disk indexes should be generated)
Few script examples could be would under hprof-oql-engine/src/test/resources/oql/ path.