Re: changing MyDatabaseId - Mailing list pgsql-hackers

From Markus Wanner
Subject Re: changing MyDatabaseId
Date
Msg-id 4CE3DF07.5080909@bluegap.ch
Whole thread Raw
In response to Re: changing MyDatabaseId  (Alvaro Herrera <alvherre@commandprompt.com>)
Responses Re: changing MyDatabaseId
List pgsql-hackers
On 11/17/2010 02:19 PM, Alvaro Herrera wrote:
> Well, the autovacuum mechanism involves a lot of back-and-forth between
> launcher and postmaster, which includes some signals, a fork() and
> backend initialization.  The failure possibilities are endless.
> 
> Fork failure communication is similarly brittle.

I certainly agree to that. However, a re-connecting mechanism wouldn't
allow us to get rid of the existing avworker startup infrastructure
entirely.

And for increased robustness, we'd require a less brittle re-connecting
mechanism. Given Robert's list, that doesn't seem trivial, either. (But
still doable, yes).

> Right now we have this "delay", if the process is not up and running in
> 60 seconds then we have to assume that "something" happened, and we no
> longer wait for it.  If we knew the process was already there, we could
> leave it alone; we'd know it would get to its duty eventually.

You are assuming presence of pool here. Which is fine, it's just not
something that a re-connecting feature would solve per se. (Says he who
coded the bgworkers pool thingie).

Regards

Markus Wanner


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