[Pgpool-hackers] retry of health check

[Fujii Masao]

On Tue, Mar 9, 2010 at 3:07 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>> The health_check() in main.c retries to execute the health check from
>> the beginning only when the message other than the ErrorResponse
>> arrives from the backend and it fails in sending the Terminate message
>> to the backend. Why do we need to retry that only in that case?
>> The retry with template1 seems useless. Am I missing something?
>
> Thanks for the report. You are right! Here is the patch which should
> fix the problem.

This patch seems to change the pgpool's basic policy of the health check.
Is this OK?

Currently, even if the server cannot accept any queries for some reasons
(e.g., the health_check_user has not been defined yet, the number of
connections has reached to max_connections, or etc), the health check
regards the server as running normally. In other words, the health check
returns OK even if it receives the ErrorResponse message from the server.

On the other hand, with the patch, if the ErrorResponse message arrives,
the health check always regards the server as dead. This change has a
significant impact on the existing users?

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center