> 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 they could afford slightly outdated results.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result is sometimes outdated?"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