Fixing no pg_hba.conf entry and password authentication failed by Root Cause
How to map six PostgreSQL connection errors onto the network, pg_hba, and authentication layers and diagnose them in 30 seconds. Covers an error-text lookup table, ss and pg_hba_file_rules diagnostics, first-match rules, PG14 scram-sha-256
PostgreSQL too many clients already: 30-second triage recovery runbook
Use a 30-second triage table to classify PostgreSQL FATAL: sorry, too many clients already as a spike, leak, or misconfig, then recover immediately with copy-paste SQL—terminate idle in transaction, tune max_connections, and decide on pgbou
When docker compose depends_on Doesn't Wait for Your DB — Fix connection refused with healthcheck
Does your app still die with connection refused even with depends_on? Here's why depends_on only guarantees start order, and how to wait until the service is actually ready with healthcheck + condition: service_healthy — copy-paste recipes
5 Ways to Fix PostgreSQL password authentication failed for user postgres
Diagnose the PostgreSQL 'password authentication failed for user postgres' error by five causes in order—typos, unset password, pg_hba.conf scram/md5 mismatch, and Docker networking. Includes copy-paste commands for psql, JDBC, and Spring.