knktc's Notes

How to choose a better starting sector in parted to avoid partition alignment warnings on large disks.

RabbitMQ restricts the default guest user to localhost by default; here is how to change it, and why it is risky.

A simple way to inspect a multiprocessing Pool and estimate how many tasks are still running by checking pool._cache.

If a Hadoop Streaming Python job cannot import a third-party library, pass PYTHONPATH through -cmdenv.

A tiny shared library that crashes on purpose, useful for testing how Python behaves when a ctypes-loaded C library segfaults.

A modified version of pssh that supports storing a different password for each host in the host list file.

When GPG works in a shell but fails in cron, adding --no-tty and --homedir usually fixes it.

Hive does not handle IN and NOT IN the same way as MySQL or PostgreSQL, so these patterns can be rewritten with joins.

A small shell script that estimates inbound traffic on a Linux network interface over a configurable time window.

A quick checklist for troubleshooting broken crontab jobs, including syntax issues, service status, file format, and permissions.