Ari,
> Very many people have stayed on the 5.0.x releases due to perceived problems
> with 5.1.x. There is nothing in either of those releases that should make the
> slightest difference to Cayenne.
I did some more research and found a report with *similar* symptoms
http://bugs.mysql.com/bug.php?id=16979
The complaint is that in an early 5.0 MySQL:
"When accessing the auto-increment counter, InnoDB uses a special
table-level AUTO-INC lock that it keeps to the end of the current SQL
statement, "
This appears to document anomalous locking behavior associated with MySQL 5.0
innodb, that the subsequent postings suggest will be fixed in 5.1. If this is
in fact table level locking then a simple update could cause problems when
there are multiple users reading & writing data. (I have no idea how to
reproduce this, or test the extent to which the innodb locking has cascading
affects, however if this could cause connection problems then it could be the
culprit)
You guys know way more about DBMS behavior than I; does this sound like it
could be the problem (remember the logs show the locking exception is typically
just prior to the connection exception)?
If so, then a simple upgrade to MySQL 5.1 might fix the problem.
Thanks,
Joe
On Apr 16, 2010, at 10:51 PM, Aristedes Maniatis wrote:
> On 17/04/10 11:49 AM, Joe Baldwin wrote:
>> the database is running on a production machine:
>>
>> Sun MySQL - 5.0.51a
>> Linux 2.6.25-14.fc9.x86_64 (amd64)
>> Java 1.6
>>
>> One thing I noticed was that my webhost is using MySQL 5.0.51a, while
>> Wikipedia documents 5.1.45 as the most recent stable release. The JDBC
>> driver is provided by the host.
>>
>> I am not sure why they are using 5.0.51a. Could this cause a problem with
>> Cayenne?
>
>
> Very many people have stayed on the 5.0.x releases due to perceived problems
> with 5.1.x. There is nothing in either of those releases that should make the
> slightest difference to Cayenne.
>
> You should look at running a recent version of the JDBC driver.
>
> Ari
>
>
> --
> -------------------------->
> Aristedes Maniatis
> ish
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