Debug: Linux process using too much memory (OOM)

Process gets killed by OOM killer or system becomes unresponsive due to memory pressure.

Diagnosis and fixes:

1. Find memory hogs:

ps aux --sort=-%mem | head -20
top -o %MEM

1. Check OOM killer logs:

dmesg | grep -i 'oom\|out of memory\|killed process'
journalctl -k | grep -i oom

1. Detailed process memory:

cat /proc/<pid>/status | grep -i vm
pmap -x <pid> | tail -5

1. For Node.js: Increase heap limit

node --max-old-space-size=4096 app.js

1. For Java: Set heap size

java -Xmx4g -Xms2g -jar app.jar

1. For containers: Set memory limits

docker run --memory=2g --memory-swap=2g app

1. System-level: Adjust overcommit

cat /proc/sys/vm/overcommit_memory
# 0=heuristic, 1=always, 2=never overcommit

1. Prevent OOM kills for critical processes:

echo -1000 > /proc/<pid>/oom_score_adj