XF 1.5 Lock wait timeout exceeded with Account Confirmation

[Movie Prop Sites]

I have been receiving this error on a fairly regular basis on one of our sites. It is strange because we have several Xenforo-based sites on the same server with essentially the same build, yet this is the only one that seems to get these errors. Any idea what might be causing it? Is this some type of spammer issue or an actual problem with the site itself?

When I look at that particular user,"IkariNoKen" he registered just one minute before the time of this error and he is a full, validated member, so his registration clearly went through and he was even able to confirm his membership, so it doesn't seem that this error is actually stopping people from registering.

Error Info
Zend_Db_Statement_Mysqli_Exception: Mysqli statement execute error : Lock wait timeout exceeded; try restarting transaction - library/Zend/Db/Statement/Mysqli.php:214
Generated By: IkariNoKen, Wednesday at 8:46 PM
Stack Trace
#0 /xxx/library/Zend/Db/Statement.php(297): Zend_Db_Statement_Mysqli->_execute(Array)
#1 /xxx/library/Zend/Db/Adapter/Abstract.php(479): Zend_Db_Statement->execute(Array)
#2 /xxx/library/Zend/Db/Adapter/Abstract.php(632): Zend_Db_Adapter_Abstract->query('UPDATE `xf_user...', Array)
#3 /xxx/library/XenForo/DataWriter.php(1654): Zend_Db_Adapter_Abstract->update('xf_user', Array, 'user_id = 29158')
#4 /xxx/library/XenForo/DataWriter.php(1623): XenForo_DataWriter->_update()
#5 /xxx/library/XenForo/DataWriter.php(1419): XenForo_DataWriter->_save()
#6 /xxx/library/XenForo/ControllerPublic/AccountConfirmation.php(54): XenForo_DataWriter->save()
#7 /xxx/library/XenForo/FrontController.php(351): XenForo_ControllerPublic_AccountConfirmation->actionEmail()
#8 /xxx/library/XenForo/FrontController.php(134): XenForo_FrontController->dispatch(Object(XenForo_RouteMatch))
#9 /xxx/index.php(13): XenForo_FrontController->run()
#10 {main}
Request State
array(3) {
  ["url"] => string(80) "https://xxx/account-confirmation/29158/email?c=4Tf9fC7jqefRttTU"
  ["_GET"] => array(1) {
   ["c"] => string(16) "4Tf9fC7jqefRttTU"
  }
  ["_POST"] => array(0) {
  }
}

 

[Movie Prop Sites]

Following up on this issue as we are still experiencing it and now seeing it happen on two of our sites.

 

[Paul B]

If it's happening on two different sites on the same server, then that would point to underlying server issues.

It could be a temporary overload situation, or, if it's happening at the same time each day, a process may be running (e.g. a backup).

 

[Movie Prop Sites]

Just checked further. It is happening on 4 sites, all on the same server, all at different times, with no consistent time within a site or between sites. It seems to happen primarily when a user receives a registration confirmation email (but not every time we have a registration), but I have also seen it happen on rare occasion during a login.

If it's happening on two different sites on the same server, then that would point to underlying server issues.

It could be a temporary overload situation, or, if it's happening at the same time each day, a process may be running (e.g. a backup).

 

[Mike]

The location where this is happening is probably more of a red herring than anything. This is just a basic user update and there isn't much else interesting happening at this point.

This does generally point to a server load issue though. It could be database specific and would certainly vary depending on the load individual sites get. Backups are certainly a potential cause (as depending on approach, they can lock the DB and take a long time). If not, then the server load may need to be monitored to see if it's spiking at times.