[pgpool-hackers: 259] Re: Patch for new parameter for searching primary node timeout

Tatsuo Ishii ishii at postgresql.org
Mon May 27 23:32:26 JST 2013


> Hi Tatsuo
> 
> Thanks for the comments and review. I will submit the updated patch after
> taking care of the comments.
> Please just clarify on one of the points, what should be the correct
> behaviour of setting the search_primary_node_timeout = 0
> 
> Retrying forever OR  Try just one time.?
>
> Thanks
> Usama

I vote for "retrying forever".
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp

> On Mon, May 27, 2013 at 7:07 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
> 
>> Hi Usama,
>>
>> Welcome to pgpool developer's community!
>>
>> > I have been working on pgpool-II TODO item to add a new configuration
>> > parameter for searching the primary node timeout after failover.
>> Currently
>> > pgpool-II uses "recovery_timeout" config parameter as a timeout for
>> > searching the primary node after failover which is not originally meant
>> for
>> > the purpose.
>> > The attached small patch is my first pgpool-II patch which adds the new
>> > configuration parameter "search_primary_node_timeout", which can be used
>> > for setting the timeout for searching the primary node after failover.
>>
>> I have looked into the patch. Here's my comment.  First, you need
>> patch for doc/pgpool-en.html.
>>
>> Second,
>>
>> +search_primary_node_timeout = 90
>> +                                   # Timeout in seconds to search for the
>> +                                   # primary node at failover
>> +                                   # 0 means no wait
>>
>> I am not sure what you suppose when search_primary_node_timeout = 0.
>> If you mean retrying forever, the code below does not do that. Rather,
>> find_primary_node() is never called, thus
>> find_primary_node_repeatedly() always returns -1.
>>
>> +       for (sec = 0; sec < pool_config->search_primary_node_timeout;
>> sec++)
>>         {
>>                 node_id = find_primary_node();
>>
>> Third, the default timeout 90 seconds seems too long. Promoting to
>> primary should take less than 10 seconds unless there's huge back log
>> of WAL. What about set the default to 10?
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese: http://www.sraoss.co.jp
>>


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