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SQLSTATE 08006

PostgreSQL connection_failure

An established PostgreSQL connection failed while the client was using it, leaving the current operation interrupted or uncertain.

PostgreSQL client/server connectionConnectivityhigh
Exact message
connection failure

Also searched as: connection_failure · server closed the connection unexpectedly

What it means

The client lost a session because of server termination, network interruption, proxy timeout, process failure, or protocol-level disruption. The SQLSTATE alone does not establish which layer failed.

Typical trigger conditions

  • Database restart or failover
  • Load balancer or firewall idle timeout
  • Backend process crash
  • Network path interruption
Evidence before intervention

First diagnostic checks

1

Correlate both ends

Compare application, pooler, PostgreSQL and infrastructure events by timestamp and connection identity.

2

Test a fresh connection

Determine whether the endpoint is currently reachable without reusing the failed pool session.

pg_isready -h <host> -p <port> -d <database>
3

Review timeout layers

Compare client, pooler, proxy, firewall and server keepalive settings.

Version and platform notes

The class 08 SQLSTATE is stable; the accompanying driver exception and server log usually provide the discriminating evidence.

Engineering signal

Follow PostgreSQL failures and fixes

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