Example Debugging Session using DTrace and MDB
summary
Uses DTrace and MDB on SmartOS/Manta to debug a real Node.js memory leak. Takes gcore dumps, runs findjsobjects and sees one object count jump ~4,000 → ~8,000, then uses pmap to show heap stays ~3.5MB while total RSS/VM grows ~374MB→380MB. A small DTrace script probes mmap, prints allocation size and a jstack backtrace, and points to a closure in leak2.js (line 13/27) as the actual culprit.
AI-written summary · about
chapters (6)
- 0:00Start
- 3:58Run mdb(1) on the Dumps
- 7:58How is Memory Allocated?
- 9:39Run pmap(2) Again a little later
- 10:31Node is Using mmap(2) to Grow Space
- 13:26Acknowledgements
