MySQL Bugs: #41537: falcon_select fails sporadiclly: lost connection

Bug #41537	falcon_select fails sporadiclly: lost connection
Submitted:	17 Dec 2008 11:48	Modified:	8 Jan 2009 23:21
Reporter:	Sven Sandberg	Email Updates:
Status:	Can't repeat	Impact on me:	None
Category:	MySQL Server: Falcon storage engine	Severity:	S2 (Serious)
Version:	6.0	OS:	Any
Assigned to:	Vladislav Vaintroub	CPU Architecture:	Any
Tags:	F_TEST, falcon_select, Lost connection, pushbuild, sporadic, test failure

Description:
falcon_select fails sporadically with this message:

falcon.falcon_select                     [ fail ]

CURRENT_TEST: falcon.falcon_select
mysqltest: At line 1427: query 'alter table t3 add t2nr int not null auto_increment primary key first' failed: 2013: Lost connection to MySQL server during query

The result from queries just before the failure was:
< snip >
amm
Aug
aud
att
Ado
select distinct substring(fld3,1,3) as a from t2 having a like "A%" limit 10;
a
ast
adm
ann
agi
afi
amm
Aug
aud
att
Ado
create table t3 (
period    int not null,
name      char(32) not null,
companynr int not 
More results from queries before failure can be found in /dev/shm/var-falcon-111/3/log/falcon_select.log

 - saving '/dev/shm/var-falcon-111/3/log/falcon.falcon_select/' to '/dev/shm/var-falcon-111/log/falcon.falcon_select/'
 - found 'core.5105' (0/5)

Trying 'gdb' to get a backtrace

Retrying test, attempt(2/3)...

How to repeat:
https://intranet.mysql.com/secure/pushbuild/showpush.pl?dir=bzr_mysql-6.0-rpl&order=93 sapsrv2/falcon
xref: http://tinyurl.com/5wxyz7

The above xref lists all 'lost connection' that happen on line 1427 of falcon_select. However, the test also fails frequently on other lines:
http://tinyurl.com/5vcwzt

run the test 120 times in a row. Does not crash. Unfortunately as logs from older crashes are not saved, I can't analyze further. Closing as can't repeat.