[pgpool-general: 2810] pgpool: stuck connections
Anna Aronova
ankaar at gmail.com
Wed May 7 23:38:57 JST 2014
Hi,
we are testing pgpool-II 3.3.3 with Postgresql 9.3 before production.
pgpool-II is configured for connection-pooling and failover for Postgresql
with streaming replication (master + 4 slaves).
In addition, we are using Postgresql for multi-tenant application. hence we
expect connections from hundreds of users.
At some point of time, the database connections started to be rejected.
Expert from pgpool.conf:
#------------------------------------------------------------------------------
# POOLS
#------------------------------------------------------------------------------
# - Pool size -
num_init_children = 8
# Number of pools
# (change requires restart)
max_pool = 240
# Number of connections per pool
# (change requires restart)
# - Life time -
child_life_time = 300
# Pool exits after being idle for this
many seconds
child_max_connections = 0
# Pool exits after receiving that many
connections
# 0 means no exit
connection_life_time = 60
# Connection to backend closes after
being idle for this many seconds
# 0 means no close
client_idle_limit = 60
# Client is disconnected after being
idle for that many seconds
# (even inside an explicit transactions!)
# 0 means no disconnection
The pgpool processes looked as below :
root 1987 1 0 Mar04 ? 00:00:00 abrt-dump-oops -d
/var/spool/abrt -rwx /var/log/messages
postgres 10053 1 0 Apr29 ? 00:01:00 /usr/bin/pgpool -f
/etc/pgpool-II/pgpool.conf -n
postgres 10060 10053 0 Apr29 ? 00:00:00 pgpool: watchdog
postgres 10061 10053 0 Apr29 ? 00:00:01 pgpool: heartbeat receiver
postgres 10062 10053 0 Apr29 ? 00:00:02 pgpool: heartbeat sender
postgres 10063 10053 0 Apr29 ? 00:00:26 pgpool: lifecheck
postgres 10072 10053 0 Apr29 ? 00:00:00 pgpool: PCP: wait for
connection request
postgres 10073 10053 0 Apr29 ? 00:01:13 pgpool: worker process
postgres 11544 10053 0 08:14 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.6(60214) idle
postgres 11553 10053 0 08:15 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.6(60196) idle
postgres 11554 10053 0 08:15 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.6(60206) idle
postgres 11557 10053 0 08:15 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.6(60200) idle
postgres 11558 10053 0 08:15 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.7(49434) idle
postgres 11559 10053 0 08:15 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.6(60210) idle
postgres 11697 10053 0 08:23 ? 00:00:11 pgpool: t_921413 tomr_qa
15.22.23.7(49431) idle
postgres 12708 10053 0 09:26 ? 00:00:01 pgpool: t_921413 tomr_qa
15.22.23.7(49427) idle
*pcp_proc_info 10 pool-vip 9898 pguser XXXXXX 11544*
toma_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:24:02 3 0 6 29783 0
toma_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:24:02 3 0 6 26487 0
toma_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:24:02 3 0 6 20197 0
tomr_qa tom_admin_exec 2014-04-30 08:15:00 2014-04-30 08:27:34 3 0 1767
8784 0
tomr_qa tom_admin_exec 2014-04-30 08:15:00 2014-04-30 08:27:34 3 0 1767
22090 0
tomr_qa tom_admin_exec 2014-04-30 08:15:00 2014-04-30 08:27:34 3 0 1767
29893 0
tomr_qa tom_admin_exec 2014-04-30 08:15:00 2014-04-30 08:27:34 3 0 1767
26598 0
tomr_qa tom_admin_exec 2014-04-30 08:15:00 2014-04-30 08:27:34 3 0 1767
20307 0
toma_qa t_103886 2014-04-30 08:15:00 2014-04-30 08:33:23 3 0 16 8964 0
toma_qa t_103886 2014-04-30 08:15:00 2014-04-30 08:33:23 3 0 16 22270 0
toma_qa t_103886 2014-04-30 08:15:00 2014-04-30 08:33:23 3 0 16 30072 0
toma_qa t_103886 2014-04-30 08:15:00 2014-04-30 08:33:23 3 0 16 26777 0
toma_qa t_103886 2014-04-30 08:15:00 2014-04-30 08:33:23 3 0 16 20489 0
tomr_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:43:55 3 0 6 9295 0
tomr_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:43:55 3 0 6 22600 0
tomr_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:43:55 3 0 6 30402 0
tomr_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:43:55 3 0 6 27106 0
tomr_qa tom_admin_lab 2014-04-30 08:15:00 2014-04-30 08:43:55 3 0 6 20818 0
*tomr_qa t_921413 2014-04-30 08:15:00 2014-04-30 08:56:37 3 0 340 9695 1*
*tomr_qa t_921413 2014-04-30 08:15:00 2014-04-30 08:56:37 3 0 340 23003 1*
*tomr_qa t_921413 2014-04-30 08:15:00 2014-04-30 08:56:37 3 0 340 30802 1*
*tomr_qa t_921413 2014-04-30 08:15:00 2014-04-30 08:56:37 3 0 340 27506 1*
*tomr_qa t_921413 2014-04-30 08:15:00 2014-04-30 08:56:37 3 0 340 21229 1*
*toma_qa t_921413 2014-04-30 08:15:00 2014-04-30 09:13:18 3 0 24 10227 0*
*toma_qa t_921413 2014-04-30 08:15:00 2014-04-30 09:13:18 3 0 24 23535 0*
*toma_qa t_921413 2014-04-30 08:15:00 2014-04-30 09:13:18 3 0 24 31335 0*
*toma_qa t_921413 2014-04-30 08:15:00 2014-04-30 09:13:18 3 0 24 28038 0*
*toma_qa t_921413 2014-04-30 08:15:00 2014-04-30 09:13:18 3 0 24 21760 0*
In the database we saw several sessions from the same user *t_921413 in
different statuses.*
postgres 21218 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33660) UPDATE waiting
postgres 21223 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33685) UPDATE waiting
postgres 21224 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33690) UPDATE waiting
postgres 21226 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33695) UPDATE waiting
postgres 21229 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33705) UPDATE waiting
postgres 21249 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33755) UPDATE waiting
postgres 21250 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(33760) UPDATE waiting
postgres 21758 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34759) idle
postgres 21759 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34760) idle
postgres 21760 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34767) idle
postgres 21761 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34770) idle
postgres 21767 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34785) idle
postgres 21771 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34800) idle
postgres 21772 5469 0 Apr30 ? 00:00:00 postgres: t_921413 toma_qa
15.22.23.6(34805) idle
postgres 22161 5469 0 Apr30 ? 00:00:00 postgres: t_921413 tomr_qa
15.22.23.6(35590) UPDATE
The problems we encountered and can't understand what is causing and if
there is a fix to it or there is a an error in configuration:
1. Application server 15.22.23.6 was taken down but pgpool still showed us
that front-end is connected (pcp_proc_info - status 1)
2. There were several idle cached connections in database that were not
closed even after there were idle for much more that 60 seconds.
3. Only after we killed all connections to database of the user t_921413
(in all nodes), other users could continue working
Please, advise!
Thank you in advance
Anna
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