RDS PostgreSQL Services

# Describe RDS instance status, Multi-AZ topology, and storage allocation
aws rds describe-db-instances \
  --db-instance-identifier prod-postgres-rds-primary \
  --query "DBInstances[0].{Status:DBInstanceStatus,EngineVersion:EngineVersion,MultiAZ:MultiAZ,AllocatedStorage:AllocatedStorage,StorageType:StorageType,IOPS:Iops}" \
  --output table

# Verify RDS CloudWatch replica lag metrics over the past hour
aws cloudwatch get-metric-data \
  --metric-data-queries '[{"Id":"m1","MetricStat":{"Metric":{"Namespace":"AWS/RDS","MetricName":"ReplicaLag","Dimensions":[{"Name":"DBInstanceIdentifier","Value":"prod-postgres-rds-replica"}]},"Period":60,"Stat":"Maximum"}}]' \
  --start-time $(date -u -v-1H +%Y-%m-%dT%H:%M:%SZ) \
  --end-time $(date -u +%Y-%m-%dT%H:%M:%SZ)

-- Safe read-only inspection of active connections, query states, and waiting locks
SELECT pid,
       usename,
       client_addr,
       state,
       wait_event_type,
       wait_event,
       now() - query_start AS query_duration,
       left(query, 80) AS query_preview
FROM pg_stat_activity
WHERE state != 'idle'
  AND pid <> pg_backend_pid()
ORDER BY query_duration DESC
LIMIT 10;