Re: pika buildfarm member failure on isolationCheck tests

From: Dan Ports <drkp(at)csail(dot)mit(dot)edu>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: R?mi Zara <remi_zara(at)mac(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, Andrew Dunstan <andrew(at)dunslane(dot)net>, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov>
Subject: Re: pika buildfarm member failure on isolationCheck tests
Date: 2011-06-21 02:18:28
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

While testing the fix for this one, I found another bug. Patches for
both are attached.

The first patch addresses this bug by re-adding SXACT_FLAG_ROLLED_BACK,
in a more limited form than its previous incarnation.

We need to be able to distinguish transactions that have already
called ReleasePredicateLocks and are thus eligible for cleanup from
those that have been merely marked for abort by other
backends. Transactions that are ROLLED_BACK are excluded from
SxactGlobalXmin calculations, but those that are merely DOOMED need to
be included.

Also update a couple of assertions to ensure we only try to clean up
ROLLED_BACK transactions.

The second patch fixes a bug in PreCommit_CheckForSerializationFailure.
This function checks whether there's a dangerous structure of the form
far ---> near ---> me
where neither the "far" or "near" transactions have committed. If so,
it aborts the "near" transaction by marking it as DOOMED. However, that
transaction might already be PREPARED. We need to check whether that's
the case and, if so, abort the transaction that's trying to commit

One of the prepared_xacts regression tests actually hits this bug.
I removed the anomaly from the duplicate-gids test so that it fails in
the intended way, and added a new test to check serialization failures
with a prepared transaction.


Dan R. K. Ports MIT CSAIL

Attachment Content-Type Size
readd-rolled-back-flag.patch text/x-diff 4.2 KB
check-conflict-prepared.patch text/x-diff 3.9 KB

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Pavel Stehule 2011-06-21 03:51:45 Re: Fwd: Keywords in pg_hba.conf should be field-specific
Previous Message Brendan Jurd 2011-06-21 01:25:07 Re: Fwd: Keywords in pg_hba.conf should be field-specific