Re: [Postgres-xc-developers] Coordinator/Datanode crash detection

[Koichi S. <koi...@gm...>]

Because 9.3 merge will not be done in 1.1, I don't think it's feasible
at present.   Second means will be to use PQ* functions.   Anyway,
this will be provided by pgxc_monitor.  May be a good idea to use
custom background, but this could be too much because the requirement
is very small.

Regards;
----------
Koichi Suzuki


2013/3/8 Michael Paquier <mic...@gm...>:
>
>
> On Fri, Mar 8, 2013 at 11:51 AM, Koichi Suzuki <koi...@gm...>
> wrote:
>>
>> I didn't have reactions to this.   Again, we need to detect if
>> coordinator/datanode is running even when gtm is down.   Select 1 or
>> select now does not for this purpose (it works for log shipping slave
>> though).
>>
>> I'd like to start with the watchdog patch I submitted last July,
>> attached just in case.  This includes watchdog for gtm/gtmproxies.
>> This may not be needed so far.
>>
>> An alternative is just to test if connection with one of PQ* functions
>> succeeds.   A bit of handling at the server is involved in this
>> function and it could be used to detect if the server accepts
>> connections.
>>
>> Please understand this is specific to XC, not to PG.
>
> Watchdog processes have no place inside the core code. I think that merge
> with 9.3 will be done in a close future, so why not using an extension based
> on the facility for custom background workers introduced in 9.3. This could
> even be used with Postgres itself if it is nicely implemented, you know?
> --
> Michael