Christophe Pettus: All Your GUCs in a Row: authentication_timeout
Unauthenticated TCP connections consume backend slots until they log in or hit authentication_timeout.
Opening excerpt (first ~120 words) tap to expand
30 Apr 2026 2 min read Categories: PostgreSQL All Your GUCs in a Row: authentication_timeout A connection is not free just because it has not logged in yet. From the moment the TCP handshake completes, the would-be client is holding a backend slot counted against max_connections, and it will hold that slot until one of two things happens: it finishes the authentication protocol, or authentication_timeout kicks in and the server hangs up on it. Default is 60 seconds. Minimum is 1, maximum is 600 (10 minutes). Context is sighup. If the number is specified without units, it’s seconds. Sixty seconds is a long time for a client to complete SCRAM-SHA-256, and for most deployments the default is fine.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at Postgr.
