[pgpool-general: 3569] Re: Multiple active PGPool servers and Statement cache

[Tatsuo Ishii]

No. Currently pgpool-II stores cache invalidation info onto disk
files. We need to develop the new implementation to store such that
info onto memcached.

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

> This sounds perfect, so I could implement this now by just switching to
> memcached?
> 
> Cheers,
> James Sewell
> 
> On Friday, 20 March 2015, Tatsuo Ishii <ishii at postgresql.org> wrote:
> 
>> > Hey,
>> >
>> > This is more of a feature request. Once of our clients uses PGPool
>> > Active/Active, and they have an interest in using statement cache.
>> >
>> > My understanding is that this will not work, as an update to PGPool a
>> will
>> > not invalidate PGPool b's cache object.
>>
>> Correct.
>>
>> > Would it be possible to implement the sharing of statement cache
>> > invalidation via watchdog? Obviously this would be under the same proviso
>> > that standard streaming replication is: that a PGPool node may be
>> slightly
>> > behind the other at any one time due to network lag.
>>
>> One idea is storing invalidation info onto memcached. Pgpool-II's
>> query cache (statement cache) can already be on memcached and this is
>> not terribly hard to implement. Also this way, we could avoid the
>> concern you raise.
>>
>> What do you think?
>>
>> Best regards,
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese:http://www.sraoss.co.jp
>>
>> > Cheers,
>> >
>> > James Sewell,
>> > PostgreSQL Team Lead / Solutions Architect
>> > ______________________________________
>> >
>> >
>> >  Level 2, 50 Queen St, Melbourne VIC 3000
>> >
>> > *P *(+61) 3 8370 8000  *W* www.lisasoft.com  *F *(+61) 3 8370 8099
>> >
>> > --
>> >
>> >
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> 
> 
> -- 
> 
> James Sewell,
> PostgreSQL Team Lead / Solutions Architect
> ______________________________________
> 
> 
>  Level 2, 50 Queen St, Melbourne VIC 3000
> 
> *P *(+61) 3 8370 8000  *W* www.lisasoft.com  *F *(+61) 3 8370 8099
> 
> -- 
> 
> 
> ------------------------------
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