[BUG] Streaming replica sees the old max_connections value

Hi,

Linux 2.6.18-xenU-ec2-v1.0 (Engineyard)
Gentoo Base System release 1.12.11.1
PostgreSQL 9.2.4

We have a master and two streaming replicas.

Today, when I tried to change a value of max_connections I faced a
strange postgres behavior on the replicas. The old value was 500. I
changed it in the config files of all the servers to 100. Then I
restarted postgres the master and everything was fine. However, when I
restarted it the replicas I got a fatal on both of them:

[...]
LOG:  database system is shut down
LOG:  database system was shut down in recovery at 2014-03-07 19:00:49 GMT
LOG:  entering standby mode
FATAL:  hot standby is not possible because max_connections = 100 is a
lower setting than on the master server (its value was 500)
LOG:  startup process (PID 12187) exited with exit code 1
[...]

I checked if the new setting had been applied on the master, and it was:

[local]:5432 postgres@postgres=# show max_connections
[local]:5432 postgres@postgres-# ;
 max_connections
-----------------
 100
(1 row)

I restarted the replicas again with the same sad result. So, finally,
I rolled the max_connections back to 500 and successfully restarted
postgres on all the servers starting from the master.

Are there any explanation of why the replicas didn't see the changes
and how to work around it?

Thank you.

--
Kind regards,
Sergey Konoplev
PostgreSQL Consultant and DBA

http://www.linkedin.com/in/grayhemp
+1 (415) 867-9984, +7 (901) 903-0499, +7 (988) 888-1979
gray.ru@gmail.com