Re: SR standby hangs

On Fri, Feb 18, 2011 at 2:50 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Fri, Feb 18, 2011 at 2:35 PM, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
>>> It's not running HS, so there's no query to wait on.
>
>> That seems to imply that recovery has leaked a buffer pin.
>
> No, because then the sanity check in LockBufferForCleanup would have
> fired:
>
>        /* There should be exactly one local pin */
>        if (PrivateRefCount[buffer - 1] != 1)
>                elog(ERROR, "incorrect local pin count: %d",
>                         PrivateRefCount[buffer - 1]);

Hmm, yeah.

> Some sort of deadly embrace with the bgwriter, maybe?

Maybe.

I think it'd be useful to know what the buffer header thinks the
refcount on that buffer is, and what the startup process and the
bgwriter each have for PrivateRefCount[buffer].

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company