[pgpool-general: 5508] Re: Resetting Pgpool cache

Tatsuo Ishii ishii at sraoss.co.jp
Fri May 19 08:04:39 JST 2017


Sounds reasonable request. Implementing the feature is not trivial
however. Problem is, when the cache is about to reset, there may be
concurrent sessions which are already accessing the cache in the
shared memory. For example, a session is returning query results from
cache. Another sesson is just registering a new cache entry. I have
added this our TODO.

http://pgpool.net/mediawiki/index.php/TODO#Allow_to_reset_in_memory_query_cache_in_the_shared_memory_without_restarting_Pgpool-II

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

> We host several applications on the same DB. Sometimes  folks apply
> patches/update to some databases by directly connecting to the DB instead
> of through pgpool. To fix the problem, I have to restart the service which
> brings down all the applications connected to the pgpool service. These
> applications now have to create brand new DB connections to continue
> working which is pretty drastic.
> 
> Having an option to reset cache in such a scenario without bringing the
> service down is convenient.  Then I just have to take a performance hit
> till the cache warms up again.
> -AJ
> 
> On Thu, May 18, 2017 at 3:16 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
> 
>> > Is there a way to reset the entire cache without restarting the pgpool
>> > service using SQL when using shmem?
>>
>> No. Sorry. Why do you need it?
>>
>> Best regards,
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese:http://www.sraoss.co.jp
>>


More information about the pgpool-general mailing list