MySQL Bugs: #28167: Poor performance building connection string

Bug #28167	Poor performance building connection string
Submitted:	30 Apr 2007 18:06	Modified:	3 May 2007 11:23
Reporter:	Maxim Mass	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / NET	Severity:	S5 (Performance)
Version:	5.0.6	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
Having a db call with 5.0.6 within a tight loop shows a significant performance hit dealing with building the connection string. Please take a look at the below profiler output that shows that far more time is spent building a connection (even though it should be pooled) than making the db call itself.

To summarize the attached profiler info, with 1148 calls taking a total of 58seconds, 11seconds was spent waiting on executereader but 40 seconds was spent in MySqlConnectionStringBuilder. This problem does NOT occur in 1.0.9!

How to repeat:
Put any db call in a tight loop and measure the performance with a profiling tool.

Suggested fix:
Try to cache the built connection string objects and ensure that it's not rebuilt unnecessarily.

profiler output

Attachment: mysql 5.0.6 .net connector performance.txt (text/plain), 11.31 KiB.

Patch to cache the ConnectionStringBuilder instances so they're not recreated

Attachment: ConnectionStringBuilderCaching.patch (application/octet-stream, text), 1.62 KiB.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/25944

Fixed in 5.0.7 and 5.1.1

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/25946

A note has been added to the 5.0.7 and 5.1.1 changelogs.