Complete procedures with a way back.

Diagnose MySQL ERROR 2002 and ERROR 2003 without guessing: separate a missing or mismatched Unix socket from a stopped service, wrong TCP port, bind-address policy, DNS, firewall, route, and certificate-verified TLS failure.

Diagnose MySQL ERROR 1045 by proving the selected server, transport, client origin, matching user@host account, authentication plugin, lock state, password state, and TLS policy before changing credentials or grants.

Issue identities from a trusted CA, protect private keys, require encrypted accounts, configure hostname verification, rotate certificates, and test downgrade resistance.

Install MariaDB from an official distribution or MariaDB repository, constrain networking, create an administrator path, enable logs, and prove restart safety.

Create source-scoped accounts, use roles, enforce TLS and password policy, rotate without command-line leakage, test denial, and retire access.

Create a consistent logical backup, restore it into isolation, verify representative data, and retain evidence.

Prepare source and replica identities, enable GTIDs and binary logs, seed from a verified backup, require TLS, start replication, and test lag and restart.

Install MySQL, remove unsafe defaults, create a least-privilege application database, optionally allow restricted TLS network access, and prove backup readiness.

Define recovery objectives, create a least-privilege backup identity, capture schemas and objects consistently, encrypt offsite, and run an isolated restore test.

Baseline workload, enable bounded slow logging, protect and rotate files, summarize candidates, use EXPLAIN ANALYZE carefully, and prove improvement.

Install from a trusted package or verified upstream release, isolate configuration secrets, add TLS and network authentication gates, disable dangerous defaults, and test database TLS.

Deploy phpMyAdmin on an isolated FPM pool, protect it with network and HTTP authentication, verify database TLS, deny unsafe paths, and validate updates.