[pgpool-general: 7131] Re: Error with pg_dump

[Bo Peng]

Hello,

Could you share your pgpool.conf and provide a scenario to reproduce this issue?

On Mon, 06 Jul 2020 15:31:09 +0000
"Giancarlo Celli" <giancarlo.celli at flottaweb.com> wrote:

> I add that I tried to check the active connections and I see numerous 
> queries in idle state with the words:
> 
> DISCARD ALL
> 
> Why?
> 
> 
> ------ Messaggio originale ------
> Da: "Giancarlo Celli" <giancarlo.celli at flottaweb.com>
> A: pgpool-general at pgpool.net
> Inviato: 06/07/2020 17:21:35
> Oggetto: [pgpool-general: 7124] Error with pg_dump
> 
> >Hi,
> >recently I'm having problems with pg_dump on pgpool. The master node 
> >server crashes and the switch occurs on the standby. Here are the lines 
> >of the pgpool.log:
> >
> >LOG:  pool_read_kind: error message from master backend:sorry, too many 
> >clients already
> >ERROR:  unable to read message kind
> >DETAIL:  kind does not match between master(45) slot[1] (52)
> >LOG:  watchdog received the failover command from remote pgpool-II node 
> >"xx.xx.xx.xx:5432 Linux server1"
> >LOG:  watchdog is processing the failover command 
> >[DEGENERATE_BACKEND_REQUEST] received from xx.xx.xx.xx:5432 Linux 
> >server1
> >LOG:  remote pgpool-II node "xx.xx.xx.xx:5432 Linux server1" is 
> >requesting to become a lock holder for failover ID: 0
> >LOG:  lock holder request denied to remote pgpool-II node 
> >"xx.xx.xx.xx:5432 Linux server1"
> >DETAIL:  local pgpool-II node "yy.yy.yy.yy:5432 Linux server2" is 
> >already holding the locks
> >LOG:  received the failover command lock request from remote pgpool-II 
> >node "xx.xx.xx.xx:5432 Linux server1"
> >LOG:  remote pgpool-II node "xx.xx.xx.xx:5432 Linux server1" is 
> >checking the status of [FAILOVER] lock for failover ID 0
> >
> >It would seem to depend on the number of connections exceeded (from the 
> >string that appears in the log: "sorry, too many clients already"). I 
> >already have max_connections = 300. Is there a way to verify that this 
> >was the problem?
> >if I tried to execute the pg_dump directly on the standby postgresql 
> >server, without going through pgpool, using port 5433, could I avoid 
> >the problem according to you?


-- 
Bo Peng <pengbo at sraoss.co.jp>
SRA OSS, Inc. Japan