<span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)">Hi
all,</span><div
style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)"><br
/></div><div
style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)">I'vebeen
investigatingan issue with our PostgreSQL 9.1.1 (Linux x86-64 CentOS 5.8) database where restartpoints suddenly stop
beinggenerated on the streaming-replication slave after working correctly for a week or two. The symptom of the
problemis that the pg_xlog directory on the slave doesn't get cleaned up, and the log_checkpoints output
(eg. restartpointstarting: time) stops appearing.</div><div
style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)"><br
/></div><divstyle="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)">
Iwas able to extract a core dump of the bgwriter process while it was in BgWriterNap. I inspected ckpt_start_time and
last_checkpoint_time;ckpt_start_time was 1345578533 (... 19:48:53 GMT) and last_checkpoint_time was 1345578248
(... 19:44:08GMT). Based upon these values, I concluded that it's performing checkpoints but missing the "if
(ckpt_performed)"condition (ie. CreateRestartPoint returns false); it's then setting last_checkpoint_time to now - 5
minutes+ 15 seconds.</div><div
style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)"><br
/></div><divstyle="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)">
Thereseems to be two causes of a false retval in CreateRestartPoint; the first is if !RecoveryInProgress(), and the
secondis if "the last checkpoint record we've replayed is already our last restartpoint". The first condition doesn't
seemlikely; does anyone know how we might be hitting the second condition? We have continuous traffic on the master
serverin the range of 1000 txn/s, and the slave seems to be completely up-to-date, so I don't understand how we could
behitting this condition.</div><div
style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)"><br
/></div><divstyle="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)">
Mathieu</div><div
style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)"><br/></div>