Re: BUG #3245: PANIC: failed to re-find shared loc k o b j ect

Tom Lane wrote:
> I wrote:
>> Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
>>> Dave, would you please create a new binary with the attached patch? And
>>> LOCK_DEBUG and assertions and debug enabled.
>
>> Also, it would be worth adding "lockmode" to the set of things printed
>> by the panic message in the patch I sent earlier.
>
> Also: as long as we are building a custom-hacked executable to probe
> into this, let's hack it to not remove the 2PC state file, so we can
> double check what's really in there. I believe what you'd need to
> remove is the RemoveTwoPhaseFile calls at twophase.c line 1583 (where
> it thinks it's "stale") and xact.c line 4223 (where it's replaying a
> XLOG_XACT_COMMIT_PREPARED WAL record).

Yeah, sounds like a good idea.

Patch attached that incorporates all the ideas this far:

1. More verbose PANIC message, including lockmode
2. More debug info in AtPrepare_Locks. I even put a DumpLocks call in
it, that should give us a good picture of what's in the lock structures
at the time of commit
3. Instead of removing twophase-file in recovery, rename it to
*.removed. (it will be ignored by postgresql after that, because it
doesn't follow the normal naming rules of 2PC state files)

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com