[Bucardo-general] could not serialize access due to read/write

[Adam Kozłowski]

Hello all,

I have bucardo 4.4.8 swap replication (multi-master), after upgrading
one of DB's node to Postgres 9.1.3 I'm getting strange error.
Please take a look below, any clues appreciated.
Second DB node remains 8.3.7 and before upgrading there where no errors.

Days back: 3  User: bucardo  Database: bucardo  PID of Bucardo MCP: 15566
Name   Type  State                        PID   Last_good Time  I/U/D
Last_bad  Time
======+=====+============================+=====+=========+=====+=====+=========+====
sync_1| S   |RUN:15m3s>node2             |15570|3s       |0s
|0/2/0|3m48s    |16s
sync_2| S   |RUN:7m55s>node2             |15573|2s       |0s
|3/0/0|6m8s     |31s
sync_3| S   |RUN:7m6s>node2              |15571|2s       |0s
|4/0/0|5m14s    |18s
sync_4| S   |idle                        |15576|5s       |0s
|0/0/0|34m39s   |0s
sync_5| S   |idle                        |15575|7m25s    |0s
|1/0/0|2h39m45s |0s
sync_6| S   |idle                        |15574|6m23s    |5s
|0/0/0|50m29s   |17s
sync_7| S   |idle                        |15572|34m37s   |1s
|0/0/0|39m45s   |0s
sync_8| S   |off                         |     |17h30m6s |0s   |1/0/0|unknown  |



bucardo-warning.log

[Wed May 30 12:06:27 2012]  KID Kid exiting at cleanup_kid. Reason:
DBD::Pg::st execute failed: ERROR:  could not serialize access due to
read/write dependencies among transactions
DETAIL:  Reason code: Canceled on identification as a pivot, during write.
HINT:  The transaction might succeed if retried. at
/usr/local/lib/perl5/site_perl/5.10.1/Bucardo.pm line 5959.
 main error: none source error: 7 target error: none States:/40001/


postgres.log

May 30 12:03:35 pgsql9 postgres[20540]: [7-1] ERROR:  could not
serialize access due to read/write dependencies among transactions
May 30 12:03:35 pgsql9 postgres[20540]: [7-2] DETAIL:  Reason code:
Canceled on identification as a pivot, during commit attempt.
May 30 12:03:35 pgsql9 postgres[20540]: [7-3] HINT:  The transaction
might succeed if retried.
May 30 12:03:35 pgsql9 postgres[20540]: [7-4] STATEMENT:  commit
May 30 12:04:52 pgsql9 postgres[21623]: [7-1] ERROR:  could not
serialize access due to read/write dependencies among transactions
May 30 12:04:52 pgsql9 postgres[21623]: [7-2] DETAIL:  Reason code:
Canceled on identification as a pivot, during write.
May 30 12:04:52 pgsql9 postgres[21623]: [7-3] HINT:  The transaction
might succeed if retried.
May 30 12:04:52 pgsql9 postgres[21623]: [7-4] STATEMENT:..
May 30 12:04:52 pgsql9 postgres[21623]: [7-5] <>                INSERT
INTO bucardo.bucardo_track (txntime,targetdb,tablename)
May 30 12:04:52 pgsql9 postgres[21623]: [7-6] <>                SELECT
DISTINCT txntime, 'node2'::text, 17640::oid
May 30 12:04:52 pgsql9 postgres[21623]: [7-7] <>                FROM
bucardo.bucardo_delta d
May 30 12:04:52 pgsql9 postgres[21623]: [7-8] <>                WHERE
d.tablename = 17640::oid
May 30 12:04:52 pgsql9 postgres[21623]: [7-9] <>                AND NOT EXISTS (
May 30 12:04:52 pgsql9 postgres[21623]: [7-10] >                    SELECT 1
May 30 12:04:52 pgsql9 postgres[21623]: [7-11] >
FROM   bucardo.bucardo_track t
May 30 12:04:52 pgsql9 postgres[21623]: [7-12] >
WHERE  d.txntime = t.txntime
May 30 12:04:52 pgsql9 postgres[21623]: [7-13] >
AND    t.targetdb = 'node2'::text
May 30 12:04:52 pgsql9 postgres[21623]: [7-14] >
AND    t.tablename = 17640::oid
May 30 12:04:52 pgsql9 postgres[21623]: [7-15] >                );



/Adam