[pgpool-hackers: 1808] Re: Feature for recording the watchdog warnings to be displayed by pcp_watchdog_info

[Tatsuo Ishii]

Usama,

Sounds reasonable idea.

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

From: Muhammad Usama <m.usama at gmail.com>
Subject: Feature for recording the watchdog warnings to be displayed by pcp_watchdog_info
Date: Fri, 16 Sep 2016 01:23:50 +0500
Message-ID: <CAEJvTzU+DCW=WuxeOh6B2ReuMs5i2KR9goCjD-jZu626n4J3=g at mail.gmail.com>

> Hi
> 
> I was working on fixing the "[pgpool-general: 4997] Avoiding downtime when
> pgpool changes require a restart"
> And the part of the fix was to downgrade the FATAL error to WARNING when
> the configurations on the coordinator/master and the standby node differs.
> But since some configuration differences on the watchdog nodes can be
> catastrophic in some cases and the pgpool-II warning messages can be easily
> ignored,
> So I was thinking of a small watchdog feature that records all the warning
> messages generated on a watchdog node and the pcp_watchdog_info on master
> node displays all the warnings on the node.
> 
> See the attached WIP test patch.
> 
> Output of pcp_watchdog_info with the patch. The WARNING MESSAGE fields are
> added by the attached patch
> 
> [usama at localhost bin]$ ./pcp_watchdog_info -h 127.0.0.1 -p 9891  -U
> postgres  -w -v
> Watchdog Cluster Information
> Total Nodes          : 3
> Remote Nodes         : 2
> Quorum state         : QUORUM EXIST
> Alive Remote Nodes   : 2
> VIP up on local node : YES
> Master Node Name     : Linux_localhost.localdomain_9991
> Master Host Name     : localhost
> 
> Watchdog Node Information
> Node Name      : Linux_localhost.localdomain_9991
> Host Name      : localhost
> Delegate IP    : Not_Set
> Pgpool port    : 9991
> Watchdog port  : 9001
> Node priority  : 1
> Status         : 4
> Status Name    : MASTER
> WARNING MESSAGES [0]
> 
> Node Name      : Linux_localhost.localdomain_9992
> Host Name      : localhost
> Delegate IP    : Not_Set
> Pgpool port    : 9992
> Watchdog port  : 9002
> Node priority  : 1
> Status         : 7
> Status Name    : STANDBY
> WARNING MESSAGES [1]
> 0 value for num_init_children is 1 which is 4 on the master node
> 
> Node Name      : Linux_localhost.localdomain_9993
> Host Name      : localhost
> Delegate IP    : Not_Set
> Pgpool port    : 9993
> Watchdog port  : 9003
> Node priority  : 1
> Status         : 7
> Status Name    : STANDBY
> WARNING MESSAGES [3]
> 0 value for num_init_children is 1 which is 4 on the master node
> 1 value for health_check_period is 10 which is 0 on the master node
> 2 value for enable_pool_hba is OFF which is ON on the master node
> 
> 
> Thoughts and suggestions
> 
> Thanks
> Best regards
> Muhammad Usama