Re: Re: [COMMITTERS] pgsql: Make standby server continuously retry restoring the next WAL

Heikki Linnakangas wrote:
> Simon Riggs wrote:
>
>> Might it not be simpler to add a parameter onto pg_standby?
>> We send %s to tell pg_standby the standby_mode of the server which is
>> calling it so it can decide how to act in each case.
>>
>
> That would work too, but it doesn't seem any simpler to me. On the contrary.
>

I don't know that the ideas are mutually exclusive. Should the server
internals do a basic check that the files they're about to process seem
sane before processing them? Yes. Should we provide a full-featured
program that knows how far back it can delete archives rather than
expecting people to write their own? Yes. And a modified pg_standby
seems the easiest way to do that, since it already knows how to do the
computations, among other benefits.

I already have a work in progress patch to pg_standby I'm racing to
finish here that cleans up some of the UI warts in the program,
including the scary sounding and avoidable warnings Selena submitted a
patch to improve. I think I'm going to add this feature to it, too,
whether or not it's deemed necessary. I'm really tired of example
setups provided that say "just write a simple script using cp like
<trivial example>" and then supporting those non-production quality
messes in the field. My scripts for this sort of thing have more error
checking in them than functional code. And pg_standby already has a
healthy sense of paranoia built into it.

--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.us