Re: warm standby server stops doing checkpoints after a while

Frank Wittig <fw@weisshuhn.de> writes:
> The problem is that the slave server stops checkpointing after some
> hours of working (about 24 to 48 hours of conitued log replay).

Hm ... look at RecoveryRestartPoint() in xlog.c.  Could there be
something wrong with this logic?

    /*
     * Do nothing if the elapsed time since the last restartpoint is less than
     * half of checkpoint_timeout.    (We use a value less than
     * checkpoint_timeout so that variations in the timing of checkpoints on
     * the master, or speed of transmission of WAL segments to a slave, won't
     * make the slave skip a restartpoint once it's synced with the master.)
     * Checking true elapsed time keeps us from doing restartpoints too often
     * while rapidly scanning large amounts of WAL.
     */
    elapsed_secs = time(NULL) - ControlFile->time;
    if (elapsed_secs < CheckPointTimeout / 2)
        return;

The idea is that the slave (once in sync with the master) ought to
checkpoint every time it sees a checkpoint record in the master's
output.  I'm not seeing a flaw but maybe there is one here, or somewhere
nearby.  Are you sure the master is checkpointing?

            regards, tom lane