PBXT

'Failed to read auto-increment value from storage engine' error

Bug #430600 reported by Paul McCullagh on 2009-09-16

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	PBXT	Fix Committed	Undecided	Vladimir Kolesnikov

Bug Description

Auto-increment tests (e.g. ps/ai_reset_by_truncate) cause multiple 'Failed to read auto-increment value from storage engine' errors. Since the test flow is fixed and run by one thread, but the result is always different, it might be some kind of race condition inside the server/engine.

It may be that this bug is related to MySQL 6.0.9, as it has not yet been seen with 5.1.

Related branches

lp:~vkolesnikov/pbxt/pbxt-bug-430600

Merged into lp:pbxt

PBXT Core: Pending requested 2009-09-21

Revision history for this message

Paul McCullagh (paul-mccullagh) wrote on 2009-09-16:

This error is usually reported when the auto-increment value goes out of range. It must be investigated to see if this is the case here.

The activity of background threads can influence a test result, but this should never happen in a way that the result is wrong.

For example, a SELECT without an ORDER BY may return rows in a different order, depending on the timing of background threads.

Revision history for this message

Elena Stepanova (elenst) wrote on 2009-09-16:

test and result files for mysqltest Edit (2.2 KiB, application/x-tar)

As discussed by email, I'm attaching a test which might help to reproduce the error. The archive contains .test and .result files which can be put directly into mysql-test/t and mysql-test/r.

I run it as
perl ./mysql-test-run.pl --mysqld=--default-storage-engine=pbxt ai_reset_by_truncate

The test is not deterministic. Out of 10 times I've run it just now, it failed 6 times on line 400, 3 times on line 346, and one time it passed.
With innodb or myisam as a default engine it passes reliably.

MySQL 6.0.9
PBXT 1.0.09
Linux 2.6.18-92.1.10.el5 #1 SMP Wed Jul 23 03:56:11 EDT 2008 x86_64 GNU/Linux
Red Hat Enterprise Linux Server release 5.2 (Tikanga)

Vladimir Kolesnikov (vkolesnikov) on 2009-09-18