Re: pgpool question

Oleg Bartunov wrote:
> On Wed, 9 Mar 2005, Jeff Hoffmann wrote:
>
>> Oleg Bartunov wrote:
>>
>>> I'm experimenting with pgpool 2.51 on my Linux box runnung
>>> two postgresql backends: pg74:5432 and pg801:5433
>>>
>>> I configured pgpool to use pg74:5432 as primary backend and
>>> pg801:5433 as second one. Pgpool is running on default port (9999) and
>>> I configured my web application to use it, so I could start/stop
>>> backends
>>> without disturbing client (web browser).
>>>
>>> When I stop primary backend (pg74:5432) pgpool switched to backend
>>> failover from (5432) to (5433) done
>>> but when I start primary and stopped secondary backend pgpool
>>> never switched back to primary backend as expected ! I see bogus
>>> message like:
>>> starting failover from (5433) to (5433)
>>>
>>> What I'm doing wrong ?
>>
>>
>> I don't think anything. I could be wrong, but my understanding is
>> that if the primary goes down, you have to restart pgpool after
>> primary comes back up. It doesn't toggle back and forth from primary
>> <-> secondary when necessary, it only goes primary->secondary. I
>> played with pgpool for a while and came up with effectively the same
>> confused question.
>
>
> Seems, limited functionality. But, then I don't understand
> switchover options ([-s {m[aster]|s[econdary]] switch).
> What's '-s m switch' for ?

That was exactly my question so I sent a message on the pgpool mailing
list. I was trying to set up a managed downtime system where I would
switch from master to secondary, update the master, switch back to
master & update the secondary. My plan was to use the "-s" switch to do
that, but I could only switch from master to secondary, I couldn't
switch back to master using that switch. I was told that I'd have to
restart pgpool to get back to the master, which is effectively what your
question was about. I'm assuming the same mechanism is at work in both
cases.

--
Jeff Hoffmann
jeff(at)propertykey(dot)com