KvMadan / utils

utils

MemoryLeakSuspectReport.py

Command line tool to suspect the memory leak in java by analysing JCMD class histogram files.

Script will calculate the difference between two jcmd class histograms and displays top N leak suspects sorted by percentage growth.

Note: originally implemented with java coding standards later partially coverted to python coding formats. please ignore code formating.

Using this tool

Java process configuration

1. Add -XX:+UnlockDiagnosticVMOptions JVM option to java process to detect memory leak
2. Run testcase/action
3. Run forceful GC using JCMD jcmd <pid> GC.run
4. Run jcmd <pid> GC.class_histogram -all > firstHistogram.txt
5. Run test case/ action again
6. Run forceful GC again jcmd <pid> GC.run
7. Run `jcmd GC.class_histogram -all > secondHistogram.txt'

After collecting the histogram files run the script MemoryLeakSuspectReport -f firstHistogram.txt -s secondHistogram.txt to get the suspect report.

Report customizations

1. Top N Suspects report MemoryLeakSuspectReport -f firstHistogram.txt -s secondHistogram.txt --top 5
2. Package filtered reports, two filters available 'xcompany only' and '3rd party only' To filter your company specific objects add xcompany package identifier xcompany RegEx list in script MemoryLeakSuspectReport -f firstHistogram.txt -s secondHistogram.txt --top 5 3rdponly or MemoryLeakSuspectReport -f firstHistogram.txt -s secondHistogram.txt --top 5 xcompanyonly