[pgpool-hackers: 2644] Re: Load-balancing control for specific queries

[Yugo Nagata]

On Thu, 30 Nov 2017 20:24:54 +0900 (JST)
Tatsuo Ishii <ishii at sraoss.co.jp> wrote:

> Ok. Anyway both of your proposals are clearly feature additions, so
> even if we decided to implement them, we will not back patch them to
> stable branches. That's the strict project's policy.

Ok. I agreed.

> >> > One of our clients wants a new feature that force specific 
> >> > queries to be sent to the primary rather than load-balancing.
> >> > 
> >> > Even though we can do this by adding the /*NO LOAD BALANCE*/ comment
> >> > to queries, this requires modifying application codes and
> >> > this is not always possible.
> >> > 
> >> > We can think of at least two possible designs for this feature.
> >> > 
> >> > (1) Defining blacklist
> >> > 
> >> > Like black_function_list, specifying queries not to be load-balanced.
> >> > 
> >> > (2) Specifiying desitination nodes
> >> > 
> >> > Like database_redirect_preference_list, specify pairs of queries and node id
> >> > (or primary/standby).
> >> > 
> >> > In both cases, the target queries can be specified by regexp pettern or tables
> >> > included in the queries. (The client's preference is using regexp.)

By the way, which of above design do you like better? I think 2) Specifiying desitination
nodes with using regexp is good because it is the most general among the above, and
this design covers all cases that other designs can cover.

Could you please share your thought fo it if you have?

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


-- 
Yugo Nagata <nagata at sraoss.co.jp>