XF 1.5 Batch Update Threads Timeout

[jb9826]

My batch update threads tool seems to have a problem.
I disabled all add-ons, closed the forum and I am trying to delete thousands of threads.
I run the batch update and it says processing



After 1 minute and 40 seconds. I get a timeout screen



Sometimes in the error log i see this error and sometimes now

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: jb, 4 minutes ago
Stack Trace
#0 /home/jb/domains/example.com/public_html/library/Zend/Db/Statement.php(297): Zend_Db_Statement_Mysqli->_execute()
#1 /home/jb/domains/example.com/public_html/library/Zend/Db/Adapter/Abstract.php(479): Zend_Db_Statement->execute()
#2 /home/jb/domains/example.com/public_html/library/Zend/Db/Adapter/Abstract.php(661): Zend_Db_Adapter_Abstract->query()
#3 /home/jb/domains/example.com/public_html/library/XenForo/DataWriter.php(1839): Zend_Db_Adapter_Abstract->delete()
#4 /home/jb/domains/example.com/public_html/library/XenForo/DataWriter.php(1792): XenForo_DataWriter->_delete()
#5 /home/jb/domains/example.com/public_html/library/XenForo/Deferred/ThreadAction.php(62): XenForo_DataWriter->delete()
#6 /home/jb/domains/example.com/public_html/library/XenForo/Model/Deferred.php(295): XenForo_Deferred_ThreadAction->execute()
#7 /home/jb/domains/example.com/public_html/library/XenForo/Model/Deferred.php(429): XenForo_Model_Deferred->runDeferred()
#8 /home/jb/domains/example.com/public_html/library/XenForo/Model/Deferred.php(374): XenForo_Model_Deferred->_runInternal()
#9 /home/jb/domains/example.com/public_html/library/XenForo/ControllerAdmin/Tools.php(159): XenForo_Model_Deferred->run()
#10 /home/jb/domains/example.com/public_html/library/XenForo/FrontController.php(369): XenForo_ControllerAdmin_Tools->actionRunDeferred()
#11 /home/jb/domains/example.com/public_html/library/XenForo/FrontController.php(152): XenForo_FrontController->dispatch()
#12 /home/jb/domains/example.com/public_html/admin.php(13): XenForo_FrontController->run()
#13 {main}
Request State
array(3) {
  ["url"] => string(50) "https://example.com/admin.php?tools/run-deferred"
  ["_GET"] => array(1) {
    ["tools/run-deferred"] => string(0) ""
  }
  ["_POST"] => array(3) {
    ["redirect"] => string(31) "https://example.com/admin.php"
    ["execute"] => string(1) "1"
    ["_xfToken"] => string(8) "********"
  }
}

Server Error
Mysqli statement execute error : Deadlock found when trying to get lock; try restarting transaction

Zend_Db_Statement_Mysqli->_execute() in Zend/Db/Statement.php at line 297
Zend_Db_Statement->execute() in Zend/Db/Adapter/Abstract.php at line 479
Zend_Db_Adapter_Abstract->query() in Zend/Db/Adapter/Abstract.php at line 632
Zend_Db_Adapter_Abstract->update() in XenForo/DataWriter.php at line 1654
XenForo_DataWriter->_update() in XenForo/DataWriter.php at line 1623
XenForo_DataWriter->_save() in XenForo/DataWriter.php at line 1419
XenForo_DataWriter->save() in XenForo/DataWriter/Discussion.php at line 977
XenForo_DataWriter_Discussion->_updateContainerPostDelete() in XenForo/DataWriter/Discussion.php at line 764
XenForo_DataWriter_Discussion->_postDelete() in XenForo/DataWriter.php at line 1793
XenForo_DataWriter->delete() in XenForo/Deferred/ThreadAction.php at line 62
XenForo_Deferred_ThreadAction->execute() in XenForo/Model/Deferred.php at line 295
XenForo_Model_Deferred->runDeferred() in XenForo/Model/Deferred.php at line 429
XenForo_Model_Deferred->_runInternal() in XenForo/Model/Deferred.php at line 374
XenForo_Model_Deferred->run() in XenForo/ControllerAdmin/Tools.php at line 159
XenForo_ControllerAdmin_Tools->actionRunDeferred() in XenForo/FrontController.php at line 369
XenForo_FrontController->dispatch() in XenForo/FrontController.php at line 152
XenForo_FrontController->run() in /home/jb/domains/example.com/public_html/admin.php at line 13

Even trying to delete only 1 thread using the batch update gives me this error

how can i trouble shoot this. Im on a dedicated server

update:
I disabled cloudfale DNS for testing and it seems to have fixed the problem.

Why would cloudflare DNS proxy turned on be causing this issue?