Do not lock the cron anymore so we can have multiple workers

config/config.sample.php

@@ -614,17 +614,6 @@
  */
 'cron_log' => true,
 
-/**
- * Location of the lock file for cron executions can be specified here.
- * Default is within the tmp directory. The file is named in the following way:
- * owncloud-server-$INSTANCEID-cron.lock
- * where $INSTANCEID is the string specified in the ``instanceid`` field.
- * Because the cron lock file is accessed at regular intervals, it may prevent
- * enabled disk drives from spinning down. A different location for this file
- * can solve such issues.
- */
-'cron.lockfile.location' => '',
-
 /**
  * Enables log rotation and limits the total size of logfiles. The default is 0,
  * or no rotation. Specify a size in bytes, for example 104857600 (100 megabytes

cron.php

@@ -100,34 +100,11 @@
 			}
 		}
 
-		$instanceId = $config->getSystemValue('instanceid');
-		$lockFileName = 'owncloud-server-' . $instanceId . '-cron.lock';
-		$lockDirectory = $config->getSystemValue('cron.lockfile.location', sys_get_temp_dir());
-		$lockDirectory = rtrim($lockDirectory, '\\/');
-		$lockFile = $lockDirectory . '/' . $lockFileName;
-
-		if (!file_exists($lockFile)) {
-			touch($lockFile);
-		}
-
 		// We call ownCloud from the CLI (aka cron)
 		if ($appMode != 'cron') {
 			\OCP\BackgroundJob::setExecutionType('cron');
 		}
 
-		// open the file and try to lock it. If it is not locked, the background
-		// job can be executed, otherwise another instance is already running
-		$fp = fopen($lockFile, 'w');
-		$isLocked = flock($fp, LOCK_EX|LOCK_NB, $wouldBlock);
-
-		// check if backgroundjobs is still running. The wouldBlock check is
-		// needed on systems with advisory locking, see
-		// http://php.net/manual/en/function.flock.php#45464
-		if (!$isLocked || $wouldBlock) {
-			echo "Another instance of cron.php is still running!" . PHP_EOL;
-			exit(1);
-		}
-
 		// Work
 		$jobList = \OC::$server->getJobList();
 
@@ -155,10 +132,6 @@
 			}
 		}
 
-		// unlock the file
-		flock($fp, LOCK_UN);
-		fclose($fp);
-
 	} else {
 		// We call cron.php from some website
 		if ($appMode == 'cron') {