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From: Fujii Masao on 29 Jan 2010 22:54
On Sat, Jan 30, 2010 at 9:01 AM, Josh Berkus <josh(a)agliodbs.com> wrote:
> I don't think it's clear, or intuitive for users.  In SR, recovery is
> *never* done, so smart shutdown never completes (even if the master is
> shut down, when I tested it).

If you specify the trigger_file parameter in the recovery.conf, the presence
of the trigger file would complete recovery. So the existing smart shutdown
waits for it to be created. I agree that this behavior is somewhat confusing
for users.

> HOWEVER, I do believe this is an issue we could live with for 9.0 if
> it's going to lead to a whole lot of additional debugging of SR.  But if
> it's an easy fix, it'll avoid a lot of complaints on pgsql-general.

I think that the latter statement is right.

Regards,

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Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

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From: Magnus Hagander on 31 Jan 2010 12:27
On Sat, Jan 30, 2010 at 01:05, Robert Haas <robertmhaas(a)gmail.com> wrote:
> On Fri, Jan 29, 2010 at 7:01 PM, Josh Berkus <josh(a)agliodbs.com> wrote:
>>>> It's a good question if that still makes sense with Hot Standby.
>>>> Perhaps we should redefine smart shutdown in standby mode to shut down
>>>> as soon as all read-only connections have died.
>>> It's clear that "smart" shutdown doesn't work while something is active.
>>> Recovery is "active" and so we shouldn't shutdown. It makes sense, it
>>> works like this already, lets leave it. Document it if needed.
>> I don't think it's clear, or intuitive for users.  In SR, recovery is
>> *never* done, so smart shutdown never completes (even if the master is
>> shut down, when I tested it).  This is particularly an important issue
>> when you consider that some/many service and init scripts only use smart
>> shutdown ... so we'll get a lot of "bug reports" of "posgresql does not
>> shut down".
>
> Absolutely agreed.  The existing smart shutdown behavior makes sense
> from a certain point of view, but it doesn't seem very... what's the
> word I'm looking for?... smart.

Yeah.
How about we change it so it's not the default anymore?

The fact is that for most applications, it's just broken. Consider any
application that uses connection pooling, which happens to be what we
recommend people to do. A smart shutdown will never shut that server
down. But it will make it not accept new connections. Which is
probably the worst possible behavior in most cases.


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Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/

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From: Fujii Masao on 31 Jan 2010 21:49
On Sat, Jan 30, 2010 at 12:54 PM, Fujii Masao <masao.fujii(a)gmail.com> wrote:
>> HOWEVER, I do believe this is an issue we could live with for 9.0 if
>> it's going to lead to a whole lot of additional debugging of SR. But if
>> it's an easy fix, it'll avoid a lot of complaints on pgsql-general.
>
> I think that the latter statement is right.

Though we've not reached consensus on smart shutdown during
recovery yet, I wrote the patch that changes its behavior:
shut down the server (including the startup process and the
walreceiver) as soon as all read-only connections have died.
The code is also available in the 'replication' branch in
my git repository.

And, let's discuss whether something like the attached patch
is required for v9.0 or not.

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center
From: Fujii Masao on 4 Mar 2010 07:11
On Mon, Feb 1, 2010 at 11:49 AM, Fujii Masao <masao.fujii(a)gmail.com> wrote:
> On Sat, Jan 30, 2010 at 12:54 PM, Fujii Masao <masao.fujii(a)gmail.com> wrote:
>>> HOWEVER, I do believe this is an issue we could live with for 9.0 if
>>> it's going to lead to a whole lot of additional debugging of SR.  But if
>>> it's an easy fix, it'll avoid a lot of complaints on pgsql-general.
>>
>> I think that the latter statement is right.
>
> Though we've not reached consensus on smart shutdown during
> recovery yet, I wrote the patch that changes its behavior:
> shut down the server (including the startup process and the
> walreceiver) as soon as all read-only connections have died.
> The code is also available in the 'replication' branch in
> my git repository.
>
> And, let's discuss whether something like the attached patch
> is required for v9.0 or not.

There is no post about this for over a month. Can I remove this
from TODO item of SR for 9.0? Thought? Objection?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

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From: Greg Stark on 4 Mar 2010 09:55
On Thu, Mar 4, 2010 at 12:11 PM, Fujii Masao <masao.fujii(a)gmail.com> wrote:
> There is no post about this for over a month. Can I remove this
> from TODO item of SR for 9.0? Thought? Objection?
>

Does smart shutdown still fail to shut down a slave?

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greg

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