pid_stats_recorder

pid_stats_recorder

Simple tool to stream the mem, swap and cpu usage of a process with optional export to a csv file. Useful if you want to watermark process usage over time without sitting in htop watching.

Install

You must have installed Crystal 1.21.0, then run shards build. The binary will be at ./bin/pid_stats_recorder.

Usage

Run pid_stats_recorder --help to see the flags. The only required flag is --process.

All options:

• --process PID required, pid to monitor
• --frequency SECONDS sampling interval, default 1
• --export[=FILENAME] write csv (add filename or use default)
• --help help
• Ctrl+C stop, prints RSS/swap/CPU min/avg/max calcs for monitored window

Examples

• ./bin/pid_stats_recorder --process 12345
• ./bin/pid_stats_recorder --process 12345 --frequency 5
• ./bin/pid_stats_recorder --process 12345 --export
• ./bin/pid_stats_recorder --process 12345 --export=run1.csv

> ./bin/pid_stats_recorder --process 42986 --frequency 15 -e 
2026-08-15T09:38:00.026823Z   INFO - Monitoring process 42986 every 15s (Ctrl+C to stop)
2026-08-15T09:38:00.026978Z   INFO - Exporting to pid_stats_recorder_42986_20260815_193800.csv
2026-08-15T09:38:00.027133Z   INFO - RSS: 177.6 MB  Swap: 0.0 MB  CPU: -
2026-08-15T09:38:21.270176Z   INFO - RSS: 177.8 MB  Swap: 0.0 MB  CPU: 1.3%
2026-08-15T09:38:36.271016Z   INFO - RSS: 215.2 MB  Swap: 0.0 MB  CPU: 2.5%
2026-08-15T09:38:51.271315Z   INFO - RSS: 180.5 MB  Swap: 0.0 MB  CPU: 4.2%