The JusDB Database Engineering Blog

A production guide to MySQL slow query log — enabling with long_query_time and log_queries_not_using_indexes, analyzing with pt-query-digest, reading EXPLAIN output, and fixing full table scans and N+1 loops.

Most MySQL maintenance tasks still rely on cron, but systemd timers offer better logging, dependency management, and failure handling. Here's how to convert your MySQL maintenance scripts to systemd services.

Running MongoDB without TLS exposes your data to network interception and man-in-the-middle attacks. Here's how to configure TLS/SSL across your MongoDB replica set.

MySQL 8.0 exposes error logs through performance_schema.error_log — enabling SQL-based filtering by severity, component, and timestamp without grep-ing log files.

MySQL InnoDB tablespace encryption (TDE) encrypts data pages on disk without changing application code — using a two-tier keyring architecture that separates the master key from table keys.

MySQL generates multiple log files that will fill your disk if left unmanaged. Here's how to configure logrotate correctly for MySQL error logs, slow query logs, and binary logs.

ProxySQL maintains a rich internal stats schema that most teams never fully explore. Here's how to use ProxySQL's built-in monitoring to track query latency, backend health, and connection pool utilization.