Re: warm standby server stops doing checkpointsafterawhile

On Fri, 2007-06-01 at 16:58 +0400, Teodor Sigaev wrote:
> >> <2007-06-01 13:11:29.365 CEST:%> DEBUG:  00000: Ressource manager (13)
> >> has partial state information
> > To me, this points clearly to there being an improperly completed action
> > in resource manager 13. (GIN) In summary, it appears that there may be
> > an issue with the GIN code for WAL recovery and this is effecting the
> > Warm Standby.
>
> Hmm. I found that gin_xlog_cleanup doesn't reset incomplete_splits list. Is it
> possible reason of bug?

Hi Teodor,

Hmm, well, the list should be empty by that point anyway. That code is
only executed at the end of xlog replay, not half-way through as we are
seeing.

There are two possibilities:

1. There are some incomplete splits, pointing to a likely bug in GIN
2. There are so many index splits that we aren't able to make a
successful restartpoint using the current mechanism. Not a bug, but
would be an issue with how restartpoints interact with GIN (possibly
other index types also).

When we wrote this I thought (2) would be a problem, but its not shown
up to be so for btrees (yet, I guess). I have some ideas if its (2).

The attached patch should show which of these it is. I'll dress it up a
little better so we have a debug option on this. Please note I've not
tested this patch myself, so Frank if you don't mind me splatting
something at you we'll see what we see.

--
  Simon Riggs
  EnterpriseDB   http://www.enterprisedb.com