Re: max_standby_delay considered harmful

Поиск
Список
Период
Сортировка
От Yeb Havinga
Тема Re: max_standby_delay considered harmful
Дата
Msg-id 4BE2952E.3060302@gmail.com
обсуждение исходный текст
Ответ на Re: max_standby_delay considered harmful  (Rob Wultsch <wultsch@gmail.com>)
Ответы Re: max_standby_delay considered harmful  (Greg Smith <greg@2ndquadrant.com>)
SQLSTATE for Hot Standby cancellation  (Simon Riggs <simon@2ndQuadrant.com>)
SQLSTATE for Hot Standby cancellation  (Simon Riggs <simon@2ndQuadrant.com>)
Список pgsql-hackers
Rob Wultsch wrote:
> I manage a bunch of different environments and I am pretty sure that
> in any of them if the db started seemingly randomly killing queries I
> would have application teams followed quickly by executives coming
> after me with torches and pitchforks.
>
> I can not imagine setting this value to anything other than a bool and
> most of the time that bool would be -1. I would only be unleashing a
> kill storm in utter desperation and I would probably need to explain
> myself in detail after. Utter desperation means I am sure I am going
> to have to do a impactful failover at any moment and need a slave
> completely up to date NOW.
>   
That's funny because when I was reading this thread, I was thinking the 
exact opposite: having max_standby_delay always set to 0 so I know the 
standby server is as up-to-date as possible. The application that 
accesses the hot standby has to be 'special' anyway because it might 
deliver not-up-to-date data. If that information about specialties 
regarding querying the standby server includes the warning that queries 
might get cancelled, they can opt for a retry themselves (is there a 
special return code to catch that case? like PGRES_RETRY_LATER) or a 
message to the user that their report is currently unavailable and they 
should retry in a few minutes.

regards,
Yeb Havinga



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Dimitri Fontaine
Дата:
Сообщение: Re: pg_migrator to /contrib in a later 9.0 beta
Следующее
От: Robert Haas
Дата:
Сообщение: Re: max_standby_delay considered harmful