Databases
How to Find Slow Queries From the Command Line the Right Way
Find slow queries from the command line: pg_stat_statements and the log in PostgreSQL, the slow query log and mysqldumpslow in MySQL, then EXPLAIN.
7 min read
Tag
performance
18 posts
Security
How to Use ACLs and Groups to Share Files Safely Fast
Share files between users on Linux with groups, the setgid directory and ACLs: default ACLs for new files, the mask, getfacl and common pitfalls.
6 min read
Databases
How to Use SQLite for Log Analysis From the Shell Fast
Analyze logs with SQLite from the shell: parse lines into a table, import, add indexes, run top-N and time bucket queries, and know when awk is enough.
7 min read
Performance
How to Use cgroups to Cap Runaway Jobs Step by Step
Cap runaway jobs with cgroups through systemd-run and unit settings: memory and CPU limits, task limits, MemoryHigh throttling and how to see results.
7 min read
Databases
How to Use Redis cli for Quick Checks and Scripts Fast
Use redis-cli for quick checks and scripts: connect safely, inspect keys with scan, read INFO and slowlog and avoid KEYS and MONITOR in production.
6 min read
Performance
How to Use ionice and nice to Keep Servers Responsive
Keep a server responsive during heavy jobs with nice, ionice and idle scheduling: when ionice works, systemd settings, and where cgroup weights do better.
6 min read
Shell Scripting
How to Run a Shell Script as Another User Safely Fast
Run a script as another user with sudo -u, su -c or runuser, pass arguments without quoting bugs, keep the environment clean, and set up narrow sudoers rules.
6 min read
Databases
How to Dump and Restore a Docker Database Volume Fast
Dump and restore a database in Docker: pg_dump and mysqldump via docker exec, volume backups, consistency, restoring into a new container and speed.
6 min read
Performance
How to Measure Memory Use of a Command Step by Step
Measure the memory a command uses on Linux: peak RSS with GNU time, /proc status, PSS with smem, sampling a process and cgroup peak.
6 min read
Performance
How to Use time and usr bin time v for Memory and CPU
Measure time and memory of a command with GNU time: wall clock, CPU, peak memory, page faults, custom formats, logging runs and macOS differences.
6 min read
Testing
How to Use hyperfine for Performance Regression Checks
Detect performance regressions with hyperfine: benchmark runs, warmups, comparing two versions, JSON export and a CI threshold check for scripts and tools.
7 min read
Security
How to Understand and Reduce Your Attack Surface Fast
Reduce the attack surface of a Linux server: list listening ports, remove unused packages and services, close the firewall and keep patches current.
6 min read