MySQL Bugs: #41119: automatic reprepare of prepared statements fails sporadically after flush tables

Bug #41119	automatic reprepare of prepared statements fails sporadically after flush tables
Submitted:	29 Nov 2008 7:34	Modified:	26 May 2011 19:30
Reporter:	Shane Bester (Platinum Quality Contributor)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.1.30, 5.1.52	OS:	Any
Assigned to:	Paul DuBois	CPU Architecture:	Any
Tags:	Com_stmt_reprepare

Description:
According to http://dev.mysql.com/doc/refman/5.1/en/statement-repreparation.html
"Repreparation is automatic" after flush tables.  

This works in 99% of the cases, but there are some failures like this:

mysql_stmt_execute failed: Prepared statement needs to be re-prepared (1615)
host 0, thread 8 failed in prepared_query_execute for query: select * from `qa00` limit 5

How to repeat:
see attached .c testcase.

testcase. errors happen about 10 times per 30000 queries.

Attachment: bug41119.c (text/plain), 11.39 KiB.

output of testcase on Solaris:

running initializations..
client version=50130
server version=50130
pre-generating 16777216 bytes of random data
about to spawn 10 threads
..........
completed spawning new database worker threads
testcase is now running, so watch for error output
queries: 000000952
queries: 000001948
<cut>
queries: 000018419
queries: 000019019
mysql_stmt_execute failed: Prepared statement needs to be re-prepared (1615)
queries: 000019580
queries: 000020153
queries: 000020715
mysql_stmt_execute failed: Prepared statement needs to be re-prepared (1615)
queries: 000021324
queries: 000021924
queries: 000022508
queries: 000023012
queries: 000023622
mysql_stmt_execute failed: Prepared statement needs to be re-prepared (1615)
queries: 000024229
queries: 000024847

Shane,
there are 3 attempts to reprepare a statement.
If you are constantly flushing tables, each attempt may fail.
This is an artificial example. We can increase the number of attempts.
At best it should be documented.

The fact that only 3 attempts of re-preparation are made is NOT documented in http://dev.mysql.com/doc/refman/5.1/en/statement-repreparation.html. Please, fix it.

See bug #42041 also (if this report will even be back at development side).

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.