Merge pull request #258 from eileenmcnaughton/dead

Improve deadlock error handling
civicrm · Aug 8, 2019 · d86bbc7 · d86bbc7
2 parents 3832300 + 7c3733b
commit d86bbc7
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/DB/DataObject.php b/DB/DataObject.php
@@ -2415,16 +2415,22 @@ function _query($string)
             $result = $DB->query($string);
           }
           catch (PEAR_Exception $e) {
+            if ($tries == 0) {
+              // The original sin was what triggered the retry. Sometimes the retry fails because mysql has done an internal rollback
+              // of previous queries in the transaction so it has essentially failed to recover from the deadlock. If we can't
+              // recover we should return the original error.
+              $firstError = $e;
+            }
             // CRM-21489 If we have caught a DB lock - let it go around the loop until our tries limit is hit.
             // else rethrow the exception. The 2 locks we are looking at are mysql code 1205 (lock) and
             // 1213 (deadlock).
             $dbErrorMessage = $e->getCause()->getUserInfo();
             if (!stristr($dbErrorMessage, 'nativecode=1205') && !stristr($dbErrorMessage, 'nativecode=1213')) {
-              throw $e;
+              throw $firstError;
             }
             $message = (stristr($dbErrorMessage, 'nativecode=1213') ? 'Database deadlock encountered' : 'Database lock encountered');
             if (($tries + 1) === $maxTries) {
-              throw new CRM_Core_Exception($message, 0, array('sql' => $string, 'trace' => $e->getTrace()));
+              throw new CRM_Core_Exception($message, 0, array('sql' => $string, 'trace' => $firstError->getTrace()));
             }
             CRM_Core_Error::debug_log_message("Retrying after $message hit on attempt " . ($tries + 1) . ' at query : ' . $string);
             continue;