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

[Michael P. <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