[pgpool-general: 6074] Re: failover_require_consensus does not work.

[Tatsuo Ishii]

Hi Usama,

This seems to be a watchdog issue. Can you please take a look at this?

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

From: Vlad G <omenvlad at gmail.com>
Subject: [pgpool-general: 6069] failover_require_consensus does not work.
Date: Thu, 3 May 2018 15:20:04 +0300
Message-ID: <863907EE-D193-4BCA-AC6E-F25C4E4C3C6C at gmail.com>

> Hey Guys,
> I have a cluster with Pgpool-II-pg96-3.7.3 and postgresql-9.6.
> (3 x pgpool and 3 x postgresql
> The same scheme as:
> http://www.pgpool.net/docs/latest/en/html/example-cluster.html
> 
> When master node of postgresql (pgpoolpsql-1) goes down the master node of pgpool (  pgpool-1)  does not get second vote from one of the standby pgpool nodes (pgpool-2 and pgpool-3). 
> 
> If I set:
> failover_require_consensus = off
> Everything works fine.
> 
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24237: LOG:  failed to connect to PostgreSQL server on "pgpoolpsql-1:5432", getsockopt() detected error "Connection refused"
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24237: LOG:  received degenerate backend request for node_id: 0 from pid [24237]
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24217: LOG:  new IPC connection received
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24217: LOG:  watchdog received the failover command from local pgpool-II on IPC interface
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24217: LOG:  watchdog is processing the failover command [DEGENERATE_BACKEND_REQUEST] received from local pgpool-II on IPC interface
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24217: LOG:  failover requires the majority vote, waiting for consensus
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24217: DETAIL:  failover request noted
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24217: LOG:  failover command [DEGENERATE_BACKEND_REQUEST] request from pgpool-II node "pgpool-1:9999 Linux pgpool-1" is queued, waiting for the confirmation from other nodes
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24237: LOG:  degenerate backend request for node_id: 0 from pid [24237], will be handled by watchdog, which is building consensus for request
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24237: FATAL:  failed to create a backend connection
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24237: DETAIL:  executing failover on backend
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24216: LOG:  child process with pid: 24237 exits with status 256
> May 03 13:02:45 pgpool-1 pgpool[24216]: 2018-05-03 13:02:45: pid 24216: LOG:  fork a new child process with pid: 24268
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24228: LOG:  failed to connect to PostgreSQL server on "pgpoolpsql-1:5432", getsockopt() detected error "Connection refused"
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24228: LOG:  received degenerate backend request for node_id: 0 from pid [24228]
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  new IPC connection received
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  watchdog received the failover command from local pgpool-II on IPC interface
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  watchdog is processing the failover command [DEGENERATE_BACKEND_REQUEST] received from local pgpool-II on IPC interface
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  Duplicate failover request from "pgpool-1:9999 Linux pgpool-1" node
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: DETAIL:  request ignored
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  failover requires the majority vote, waiting for consensus
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: DETAIL:  failover request noted
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24228: LOG:  degenerate backend request for 1 node(s) from pid [24228], is changed to quarantine node request by watchdog
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24228: DETAIL:  watchdog is taking time to build consensus
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24228: FATAL:  failed to create a backend connection
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24228: DETAIL:  executing failover on backend
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24216: LOG:  Pgpool-II parent process has received failover request
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  new IPC connection received
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  received the failover indication from Pgpool-II on IPC interface
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  watchdog is informed of failover end by the main process
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24216: LOG:  starting quarantine. shutdown host pgpoolpsql-1(5432)
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24216: LOG:  Restart all children
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24216: LOG:  failover: set new primary node: -1
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24216: LOG:  failover: set new master node: 1
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24252: LOG:  worker process received restart request
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  new IPC connection received
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  received the failover indication from Pgpool-II on IPC interface
> May 03 13:02:46 pgpool-1 pgpool[24216]: 2018-05-03 13:02:46: pid 24217: LOG:  watchdog is informed of failover start by the main process
> May 03 13:02:46 pgpool-1 pgpool[24216]: quarantine done. shutdown host pgpoolpsql-1(5432)2018-05-03 13:02:46: pid 24216: LOG:  quarantine done. shutdown host pgpoolpsql-1(5432)
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24251: LOG:  restart request received in pcp child process
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  PCP child 24251 exits with status 0 in failover()
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  fork a new PCP child pid 24301 in failover()
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  child process with pid: 24219 exits with status 0
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  child process with pid: 24219 exited with success and will not be restarted
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  child process with pid: 24220 exits with status 0
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  child process with pid: 24220 exited with success and will not be restarted
> May 03 13:02:47 pgpool-1 pgpool[24216]: 2018-05-03 13:02:47: pid 24216: LOG:  child process with pid: 24221 exits with status 0
> 
> Around a month ago it woked fine (It seems I tested it on pgpool-3.7.2), but now it does not work. Could you tell me some parameters what it depends on or you have other thoughts. 
> 
> Best regards,
> Vladyslav
> 
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