tcp_keepalives_count — PostgreSQL configuration parameter

Specifies the number of TCP keepalive messages that can be lost before the server’s connection to the client is considered dead.

At a glance

What it does

Specifies the number of TCP keepalive messages that can be lost before the server’s connection to the client is considered dead. A value of 0 (the default) selects the operating system’s default. This parameter is supported only on systems that support TCP_KEEPCNT or an equivalent socket option (which does not include Windows); on other systems, it must be zero. In sessions connected via a Unix-domain socket, this parameter is ignored and always reads as zero.

(Description quoted from the official PostgreSQL documentation.)

How to apply a change

Can be set per session with SET, per role/database with ALTER ROLE/DATABASE ... SET, or globally in postgresql.conf.

Inspect the current value and source with SHOW tcp_keepalives_count; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'tcp_keepalives_count';.

Tuning guidance

Number of unacknowledged keepalive probes before the connection is dropped; lower it for faster dead-peer detection, raise it to tolerate transient network blips.

Reference

PostgreSQL documentation — tcp_keepalives_count.