Verified diagnostic signature
PostgreSQL is unreachable or cannot accept another client under the current policy or capacity.
Match output from postgresql, understand the likely cause, then continue with sourced, read-only checks.
- Confidence
- high
- Platforms
- linux · macos · windows
- Verified
- 2026-07-24
Recognized output
Signature matched locally
remaining connection slots are reservedOneLiners matches this pattern in your browser. Your pasted output is not stored or indexed.
Likely causes
What usually produces this signal
- Listener unavailable
- Network timeout
- pg_hba policy
- Connection exhaustion
Safe next checks
Collect evidence before changing the system
Resolve a hostname to its IP address
dig +short <domain>The output matches the expected target and exits without an error.
Check whether a TCP port accepts connections
nc -vz <host> <port>The output matches the expected target and exits without an error.
List listening TCP ports and their processes
lsof -iTCP -sTCP:LISTEN -n -PThe output matches the expected target and exits without an error.
Show Linux memory and swap usage
free -hThe output matches the expected target and exits without an error.