Re: Patroni vs pgpool II

> But, I heard PgPool is still affected by Split brain syndrome.

Can you elaborate more? If more than 3 pgpool watchdog nodes (the
number of nodes must be odd) are configured, a split brain can be
avoided.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp

> Regards,
>
> Inzamam Shafiq
> Sr. DBA
> ________________________________
> From: Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp>
> Sent: Wednesday, April 5, 2023 12:38 PM
> To: cyberdemn(at)gmail(dot)com <cyberdemn(at)gmail(dot)com>
> Cc: inzamam(dot)shafiq(at)hotmail(dot)com <inzamam(dot)shafiq(at)hotmail(dot)com>; pgsql-general(at)lists(dot)postgresql(dot)org <pgsql-general(at)lists(dot)postgresql(dot)org>
> Subject: Re: Patroni vs pgpool II
>
>> BUT, even if there is a solution that parses queries to make a decision it
>> I would not recommend anyone to use it unless all consequences are
>> understood.
>> Specifically, not every read-only query could be salefy sent to a replica,
>> because they could be lagging behind the primary.
>> Only application (developers) could decide whether for a specific query
>> they could afford slightly outdated results. Most of the popular
>> application frameworks support configuring two connection strings for this
>> purpose.
>
> I think Pgpool-II users well understand the effect of replication
> lagging because I've never heard complains like "hey, why my query
> result is sometimes outdated?"
>
> Moreover Pgpool-II provides many load balancing features depending on
> user's needs. For example users can:
>
> - just turn off load balancing
> - turn off load balancing only for specific application name
> - turn off load balancing only for specific database
> - turn off load balancing if current transaction includes write query
>
> Best reagards,
> --
> Tatsuo Ishii
> SRA OSS LLC
> English: http://www.sraoss.co.jp/index_en/
> Japanese:http://www.sraoss.co.jp