[pgpool-general: 3304] Re: Weight

[Tatsuo Ishii]

BTW from pgpool-II 3.4.0, you could achieve this by using new parameter.

database_redirect_preference_list = '.*:standby'

This will redirect all read only SELECTs to the standby (or one of
standbys if you have multiple of them) regardless of the physical node
id of primary.

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

> Well I think the real problem here is, the configuration of weight is
> bound to physical node. Ideally the weight should be bound to the
> "logical" or "role" of the node: primary (master) or standbye (slave).
> This way, you don't need to change the weight parameter after role of
> the nodes are swapped. 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
> 
>> Hello,
>> 
>> This method works well, but doesn't really play nicely with our use of
>> Puppet (which manages the config files).
>> 
>> Would anyone support looking into a pcp command to change this? I may have
>> some time early in the new year to have a go at an implementation.
>> 
>> I was thinking a very simple:
>> 
>> pcp_node_weight timeout hostname port# username password nodeID newweight
>> 
>> Maybe there is a reason this won't work / isn't a good idea though?
>> 
>> 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
>> 
>> 
>> On Tue, Jul 15, 2014 at 5:38 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>> 
>>> > Hey All,
>>> >
>>> > I have two nodes setup like so:
>>> >
>>> >    - Node 1: Master, weight 0
>>> >    - Node 2: Slave, weight 1
>>> >
>>> > This allows me to send all writes to the master and all reads to the
>>> slave.
>>> >
>>> > At some stage I promote the slave to be the new master (pcp_promote with
>>> > DISALLOW_TO_FAILOVER), then at some stage later re-provision the master
>>> as
>>> > a new slave and re-connect it (pcp_enable)
>>> >
>>> > I now have the following setup:
>>> >
>>> >    - Node 1: Slave, weight 0
>>> >    - Node 2: Master, weight 1
>>> >
>>> > This means that all write and read queries are serviced by the new
>>> master,
>>> > and none by the new slave.
>>> >
>>> > Is there a way around this? If there isn't currently could a pcp command
>>> be
>>> > implemented which would allow me to manage my own weights?
>>>
>>> You could change weight parameters in pgpool.conf then reload it.
>>>
>>> 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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>> 
>> -- 
>> 
>> 
>> ------------------------------
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