[pgpool-general: 4296] Re: Pgpool watchdog 3.4

[Derek]

Hi Yugo and Usama,

Could these trusted servers not be pgpool or Postgres servers? Eg, could the trusted server be the domain controller?

Version 3.5 sounds like a good step up from the current version, can't wait to try out the stable release. Keep up the good work.



Kind regards,
Derek.

> On 6 Jan 2016, at 3:46 PM, Yugo Nagata <nagata at sraoss.co.jp> wrote:
> 
> Hi Derek,
> 
> Although watchdog in pgpool-II 3.4 doesn't communicate after reconnecting
> as Usama said, trusted_servers is one of the paramters to avoid split-brain.
> 
> If this is specified, watchdog tries to ping to these servers, and when this
> fails, the local pgpool-II is regarded as down, so this can't become active
> or standby until restarted.
> 
> http://www.pgpool.net/docs/latest/pgpool-en.html#TRUSTED_SERVERS
> 
> 
> On Tue, 5 Jan 2016 17:24:27 +0500
> Muhammad Usama <m.usama at gmail.com> wrote:
> 
>> Hi Derek
>> 
>> Unfortunately the watchdog in pgpool-II 3.4 and older version does not
>> handle the network isolation and split-brain situations very well.
>> Currently we are in the process of overhauling the watchdog for pgpool-II
>> 3.5 which is in the beta at the moment and is planned to be released
>> sometime this month. The new enhanced watchdog for pgpool-II 3.5 has
>> addressed this and other watchdog related issues and hopefully will provide
>> a better experience and more features.
>> 
>> Thanks
>> Best regards
>> Muhammad Usama
>> 
>>> On Tue, Jan 5, 2016 at 11:33 AM, Derek <derek_kouch at yahoo.com.au> wrote:
>>> 
>>> Hi,
>>> 
>>> I've got a split brain question. Sorry for the long email.
>>> 
>>> If the master pgpool server is disconnected from the network but is still
>> running, when it reconnects after 10 minutes or longer, the master pgpool
>> server's watchdog is still thinks it is still the master and it thinks the
>> other pgpool server is down. However, it has lost the virtual ip to a new
>> master. So when the new master is down, the old master does not get the
>> virtual ip back because it still thinks it is already the master. In the
>> end, the virtual ip is down.
>>> 
>>> Does the watchdog communicate with each other after reconnecting to the
>> network after a long absence?
>>> 
>>> Is there a setting that I need to set to get the watchdogs to talk to
>> each and to resolve who is the true master and who should get control of
>> the virtual ip?
>>> 
>>> 
>>> Kind regards,
>>> Derek.
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>>> pgpool-general mailing list
>>> pgpool-general at pgpool.net
>>> http://www.pgpool.net/mailman/listinfo/pgpool-general
> 
> 
> -- 
> Yugo Nagata <nagata at sraoss.co.jp>