X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FCore%2FWorker.php;h=1aa33917071d568712289ba16cda06ba3f92e2ae;hb=11e39da6ccd4ff86be95de6af9e6f84ca67996d9;hp=76400d469848c4f218d3f19493f6137e94d473b7;hpb=dbe49a0c1ad0467c2e12e363aac5635a1f11a3ea;p=friendica.git

diff --git a/src/Core/Worker.php b/src/Core/Worker.php
index 76400d4698..1aa3391707 100644
--- a/src/Core/Worker.php
+++ b/src/Core/Worker.php
@@ -8,10 +8,9 @@ use Friendica\BaseObject;
 use Friendica\Database\DBA;
 use Friendica\Model\Process;
 use Friendica\Util\DateTimeFormat;
+use Friendica\Util\Logger\WorkerLogger;
 use Friendica\Util\Network;
 
-require_once 'include/dba.php';
-
 /**
  * @file src/Core/Worker.php
  *
@@ -23,26 +22,39 @@ require_once 'include/dba.php';
  */
 class Worker
 {
+	const STATE_STARTUP    = 1;
+	const STATE_SHORT_LOOP = 2;
+	const STATE_REFETCH    = 3;
+	const STATE_LONG_LOOP  = 4;
+
 	private static $up_start;
-	private static $db_duration;
+	private static $db_duration = 0;
+	private static $db_duration_count = 0;
+	private static $db_duration_write = 0;
+	private static $db_duration_stat = 0;
+	private static $lock_duration = 0;
 	private static $last_update;
-	private static $lock_duration;
+	private static $state;
 
 	/**
 	 * @brief Processes the tasks that are in the workerqueue table
 	 *
 	 * @param boolean $run_cron Should the cron processes be executed?
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function processQueue($run_cron = true)
 	{
-		$a = get_app();
+		$a = \get_app();
+
+		// Ensure that all "strtotime" operations do run timezone independent
+		date_default_timezone_set('UTC');
 
 		self::$up_start = microtime(true);
 
 		// At first check the maximum load. We shouldn't continue with a high load
 		if ($a->isMaxLoadReached()) {
-			logger('Pre check: maximum load reached, quitting.', LOGGER_DEBUG);
+			Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
 			return;
 		}
 
@@ -58,25 +70,25 @@ class Worker
 
 		// Count active workers and compare them with a maximum value that depends on the load
 		if (self::tooMuchWorkers()) {
-			logger('Pre check: Active worker limit reached, quitting.', LOGGER_DEBUG);
+			Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
 			return;
 		}
 
 		// Do we have too few memory?
 		if ($a->isMinMemoryReached()) {
-			logger('Pre check: Memory limit reached, quitting.', LOGGER_DEBUG);
+			Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
 			return;
 		}
 
 		// Possibly there are too much database connections
 		if (self::maxConnectionsReached()) {
-			logger('Pre check: maximum connections reached, quitting.', LOGGER_DEBUG);
+			Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
 			return;
 		}
 
 		// Possibly there are too much database processes that block the system
 		if ($a->isMaxProcessesReached()) {
-			logger('Pre check: maximum processes reached, quitting.', LOGGER_DEBUG);
+			Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
 			return;
 		}
 
@@ -86,55 +98,54 @@ class Worker
 		}
 
 		$starttime = time();
+		self::$state = self::STATE_STARTUP;
 
 		// We fetch the next queue entry that is about to be executed
-		while ($r = self::workerProcess($passing_slow)) {
-			// When we are processing jobs with a lower priority, we don't refetch new jobs
-			// Otherwise fast jobs could wait behind slow ones and could be blocked.
-			$refetched = $passing_slow;
-
+		while ($r = self::workerProcess()) {
 			foreach ($r as $entry) {
 				// Assure that the priority is an integer value
 				$entry['priority'] = (int)$entry['priority'];
 
 				// The work will be done
 				if (!self::execute($entry)) {
-					logger('Process execution failed, quitting.', LOGGER_DEBUG);
+					Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 					return;
 				}
 
 				// If possible we will fetch new jobs for this worker
-				if (!$refetched && Lock::acquire('worker_process', 0)) {
-					$stamp = (float)microtime(true);
-					$refetched = self::findWorkerProcesses($passing_slow);
-					self::$db_duration += (microtime(true) - $stamp);
+				if (!self::getWaitingJobForPID() && Lock::acquire('worker_process', 0)) {
+					self::findWorkerProcesses();
 					Lock::release('worker_process');
+					self::$state = self::STATE_REFETCH;
 				}
 			}
 
+			if (self::$state != self::STATE_REFETCH) {
+				self::$state = self::STATE_LONG_LOOP;
+			}
+
 			// To avoid the quitting of multiple workers only one worker at a time will execute the check
 			if (Lock::acquire('worker', 0)) {
-				$stamp = (float)microtime(true);
 				// Count active workers and compare them with a maximum value that depends on the load
 				if (self::tooMuchWorkers()) {
-					logger('Active worker limit reached, quitting.', LOGGER_DEBUG);
+					Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 					Lock::release('worker');
 					return;
 				}
 
 				// Check free memory
 				if ($a->isMinMemoryReached()) {
-					logger('Memory limit reached, quitting.', LOGGER_DEBUG);
+					Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 					Lock::release('worker');
 					return;
 				}
 				Lock::release('worker');
-				self::$db_duration += (microtime(true) - $stamp);
 			}
 
-			// Quit the worker once every 5 minutes
-			if (time() > ($starttime + 300)) {
-				logger('Process lifetime reached, quitting.', LOGGER_DEBUG);
+			// Quit the worker once every cron interval
+			if (time() > ($starttime + Config::get('system', 'cron_interval'))) {
+				Logger::log('Process lifetime reached, respawning.', Logger::DEBUG);
+				self::spawnWorker();
 				return;
 			}
 		}
@@ -143,29 +154,65 @@ class Worker
 		if (Config::get('system', 'worker_daemon_mode', false)) {
 			self::IPCSetJobState(false);
 		}
-		logger("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", LOGGER_DEBUG);
+		Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
+	}
+
+	/**
+	 * @brief Check if non executed tasks do exist in the worker queue
+	 *
+	 * @return boolean Returns "true" if tasks are existing
+	 * @throws \Exception
+	 */
+	private static function entriesExists()
+	{
+		$stamp = (float)microtime(true);
+		$exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
+		self::$db_duration += (microtime(true) - $stamp);
+		return $exists;
+	}
+
+	/**
+	 * @brief Returns the number of deferred entries in the worker queue
+	 *
+	 * @return integer Number of deferred entries in the worker queue
+	 * @throws \Exception
+	 */
+	private static function deferredEntries()
+	{
+		$stamp = (float)microtime(true);
+		$count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` > ?", DateTimeFormat::utcNow()]);
+		self::$db_duration += (microtime(true) - $stamp);
+		self::$db_duration_count += (microtime(true) - $stamp);
+		return $count;
 	}
 
 	/**
 	 * @brief Returns the number of non executed entries in the worker queue
 	 *
 	 * @return integer Number of non executed entries in the worker queue
+	 * @throws \Exception
 	 */
 	private static function totalEntries()
 	{
-		return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` < ?",
-			DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
+		$stamp = (float)microtime(true);
+		$count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
+		self::$db_duration += (microtime(true) - $stamp);
+		self::$db_duration_count += (microtime(true) - $stamp);
+		return $count;
 	}
 
 	/**
 	 * @brief Returns the highest priority in the worker queue that isn't executed
 	 *
 	 * @return integer Number of active worker processes
+	 * @throws \Exception
 	 */
 	private static function highestPriority()
 	{
-		$condition = ["`executed` <= ? AND NOT `done` AND `next_try` < ?", DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
+		$stamp = (float)microtime(true);
+		$condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 		$workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
+		self::$db_duration += (microtime(true) - $stamp);
 		if (DBA::isResult($workerqueue)) {
 			return $workerqueue["priority"];
 		} else {
@@ -179,11 +226,11 @@ class Worker
 	 * @param integer $priority The priority that should be checked
 	 *
 	 * @return integer Is there a process running with that priority?
+	 * @throws \Exception
 	 */
 	private static function processWithPriorityActive($priority)
 	{
-		$condition = ["`priority` <= ? AND `executed` > ? AND NOT `done` AND `next_try` < ?",
-			$priority, DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
+		$condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 		return DBA::exists('workerqueue', $condition);
 	}
 
@@ -193,28 +240,29 @@ class Worker
 	 * @param array $queue Workerqueue entry
 	 *
 	 * @return boolean "true" if further processing should be stopped
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function execute($queue)
 	{
-		$a = get_app();
+		$a = \get_app();
 
 		$mypid = getmypid();
 
 		// Quit when in maintenance
 		if (Config::get('system', 'maintenance', false, true)) {
-			logger("Maintenance mode - quit process ".$mypid, LOGGER_DEBUG);
+			Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 			return false;
 		}
 
 		// Constantly check the number of parallel database processes
 		if ($a->isMaxProcessesReached()) {
-			logger("Max processes reached for process ".$mypid, LOGGER_DEBUG);
+			Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 			return false;
 		}
 
 		// Constantly check the number of available database connections to let the frontend be accessible at any time
 		if (self::maxConnectionsReached()) {
-			logger("Max connection reached for process ".$mypid, LOGGER_DEBUG);
+			Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 			return false;
 		}
 
@@ -236,6 +284,7 @@ class Worker
 				$stamp = (float)microtime(true);
 				DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 				self::$db_duration += (microtime(true) - $stamp);
+				self::$db_duration_write += (microtime(true) - $stamp);
 			}
 
 			array_shift($argv);
@@ -243,12 +292,12 @@ class Worker
 			self::execFunction($queue, $include, $argv, true);
 
 			$stamp = (float)microtime(true);
-
 			$condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 			if (DBA::update('workerqueue', ['done' => true], $condition)) {
 				Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 			}
 			self::$db_duration = (microtime(true) - $stamp);
+			self::$db_duration_write += (microtime(true) - $stamp);
 
 			return true;
 		}
@@ -259,8 +308,11 @@ class Worker
 		}
 
 		if (!validate_include($include)) {
-			logger("Include file ".$argv[0]." is not valid!");
+			Logger::log("Include file ".$argv[0]." is not valid!");
+			$stamp = (float)microtime(true);
 			DBA::delete('workerqueue', ['id' => $queue["id"]]);
+			self::$db_duration = (microtime(true) - $stamp);
+			self::$db_duration_write += (microtime(true) - $stamp);
 			return true;
 		}
 
@@ -281,6 +333,7 @@ class Worker
 				$stamp = (float)microtime(true);
 				DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 				self::$db_duration += (microtime(true) - $stamp);
+				self::$db_duration_write += (microtime(true) - $stamp);
 			}
 
 			self::execFunction($queue, $funcname, $argv, false);
@@ -290,9 +343,13 @@ class Worker
 				Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 			}
 			self::$db_duration = (microtime(true) - $stamp);
+			self::$db_duration_write += (microtime(true) - $stamp);
 		} else {
-			logger("Function ".$funcname." does not exist");
+			Logger::log("Function ".$funcname." does not exist");
+			$stamp = (float)microtime(true);
 			DBA::delete('workerqueue', ['id' => $queue["id"]]);
+			self::$db_duration = (microtime(true) - $stamp);
+			self::$db_duration_write += (microtime(true) - $stamp);
 		}
 
 		return true;
@@ -306,164 +363,87 @@ class Worker
 	 * @param array   $argv        Array of values to be passed to the function
 	 * @param boolean $method_call boolean
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	private static function execFunction($queue, $funcname, $argv, $method_call)
 	{
-		$a = get_app();
-
-		$mypid = getmypid();
+		$a = \get_app();
 
 		$argc = count($argv);
 
-		$new_process_id = System::processID("wrk");
+		$logger = $a->getLogger();
+		$workerLogger = new WorkerLogger($logger, $funcname);
 
-		logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
+		$workerLogger ->info("Process start.", ['priority' => $queue["priority"], 'id' => $queue["id"]]);
 
 		$stamp = (float)microtime(true);
 
 		// We use the callstack here to analyze the performance of executed worker entries.
 		// For this reason the variables have to be initialized.
-		if (Config::get("system", "profiler")) {
-			$a->performance["start"] = microtime(true);
-			$a->performance["database"] = 0;
-			$a->performance["database_write"] = 0;
-			$a->performance["cache"] = 0;
-			$a->performance["cache_write"] = 0;
-			$a->performance["network"] = 0;
-			$a->performance["file"] = 0;
-			$a->performance["rendering"] = 0;
-			$a->performance["parser"] = 0;
-			$a->performance["marktime"] = 0;
-			$a->performance["markstart"] = microtime(true);
-			$a->callstack = [];
-		}
-
-		// For better logging create a new process id for every worker call
-		// But preserve the old one for the worker
-		$old_process_id = $a->process_id;
-		$a->process_id = $new_process_id;
+		$a->getProfiler()->reset();
+
 		$a->queue = $queue;
 
-		$up_duration = number_format(microtime(true) - self::$up_start, 3);
+		$up_duration = microtime(true) - self::$up_start;
 
 		// Reset global data to avoid interferences
 		unset($_SESSION);
 
+		// Set the workerLogger as new default logger
+		Logger::init($workerLogger);
 		if ($method_call) {
 			call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 		} else {
 			$funcname($argv, $argc);
 		}
+		Logger::init($logger);
 
-		$a->process_id = $old_process_id;
 		unset($a->queue);
 
 		$duration = (microtime(true) - $stamp);
 
-		self::$up_start = microtime(true);
-
 		/* With these values we can analyze how effective the worker is.
 		 * The database and rest time should be low since this is the unproductive time.
 		 * The execution time is the productive time.
 		 * By changing parameters like the maximum number of workers we can check the effectivness.
 		*/
-		logger(
-			'DB: '.number_format(self::$db_duration, 2).
-			' - Lock: '.number_format(self::$lock_duration, 2).
-			' - Rest: '.number_format($up_duration - self::$db_duration - self::$lock_duration, 2).
-			' - Execution: '.number_format($duration, 2),
-			LOGGER_DEBUG
-		);
+		$dbtotal = round(self::$db_duration, 2);
+		$dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
+		$dbcount = round(self::$db_duration_count, 2);
+		$dbstat  = round(self::$db_duration_stat, 2);
+		$dbwrite = round(self::$db_duration_write, 2);
+		$dblock  = round(self::$lock_duration, 2);
+		$rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
+		$exec    = round($duration, 2);
 
+		$logger->info('Performance log.', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
+
+		self::$up_start = microtime(true);
+		self::$db_duration = 0;
+		self::$db_duration_count = 0;
+		self::$db_duration_stat = 0;
+		self::$db_duration_write = 0;
 		self::$lock_duration = 0;
+		self::$state = self::STATE_SHORT_LOOP;
 
 		if ($duration > 3600) {
-			logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", LOGGER_DEBUG);
+			$logger->info('Longer than 1 hour.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' =>   round($duration/60, 3)]);
 		} elseif ($duration > 600) {
-			logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+			$logger->info('Longer than 10 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' =>   round($duration/60, 3)]);
 		} elseif ($duration > 300) {
-			logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+			$logger->info('Longer than 5 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' =>   round($duration/60, 3)]);
 		} elseif ($duration > 120) {
-			logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+			$logger->info('Longer than 2 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' =>   round($duration/60, 3)]);
 		}
 
-		logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds. Process PID: ".$new_process_id);
-
-		// Write down the performance values into the log
-		if (Config::get("system", "profiler")) {
-			$duration = microtime(true)-$a->performance["start"];
-
-			$o = '';
-			if (Config::get("rendertime", "callstack")) {
-				if (isset($a->callstack["database"])) {
-					$o .= "\nDatabase Read:\n";
-					foreach ($a->callstack["database"] as $func => $time) {
-						$time = round($time, 3);
-						if ($time > 0) {
-							$o .= $func.": ".$time."\n";
-						}
-					}
-				}
-				if (isset($a->callstack["database_write"])) {
-					$o .= "\nDatabase Write:\n";
-					foreach ($a->callstack["database_write"] as $func => $time) {
-						$time = round($time, 3);
-						if ($time > 0) {
-							$o .= $func.": ".$time."\n";
-						}
-					}
-				}
-				if (isset($a->callstack["dache"])) {
-					$o .= "\nCache Read:\n";
-					foreach ($a->callstack["dache"] as $func => $time) {
-						$time = round($time, 3);
-						if ($time > 0) {
-							$o .= $func.": ".$time."\n";
-						}
-					}
-				}
-				if (isset($a->callstack["dache_write"])) {
-					$o .= "\nCache Write:\n";
-					foreach ($a->callstack["dache_write"] as $func => $time) {
-						$time = round($time, 3);
-						if ($time > 0) {
-							$o .= $func.": ".$time."\n";
-						}
-					}
-				}
-				if (isset($a->callstack["network"])) {
-					$o .= "\nNetwork:\n";
-					foreach ($a->callstack["network"] as $func => $time) {
-						$time = round($time, 3);
-						if ($time > 0) {
-							$o .= $func.": ".$time."\n";
-						}
-					}
-				}
-			}
+		$workerLogger->info('Process done. ', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' =>   number_format($duration, 4)]);
 
-			logger(
-				"ID ".$queue["id"].": ".$funcname.": ".sprintf(
-					"DB: %s/%s, Cache: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
-					number_format($a->performance["database"] - $a->performance["database_write"], 2),
-					number_format($a->performance["database_write"], 2),
-					number_format($a->performance["cache"], 2),
-					number_format($a->performance["cache_write"], 2),
-					number_format($a->performance["network"], 2),
-					number_format($a->performance["file"], 2),
-					number_format($duration - ($a->performance["database"]
-						+ $a->performance["cache"] + $a->performance["cache_write"]
-						+ $a->performance["network"] + $a->performance["file"]), 2),
-					number_format($duration, 2)
-				),
-				LOGGER_DEBUG
-			);
-		}
+		$a->getProfiler()->saveLog($a->getLogger(), "ID " . $queue["id"] . ": " . $funcname);
 
 		$cooldown = Config::get("system", "worker_cooldown", 0);
 
 		if ($cooldown > 0) {
-			logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
+			$logger->info('Cooldown.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'cooldown' => $cooldown]);
 			sleep($cooldown);
 		}
 	}
@@ -472,6 +452,7 @@ class Worker
 	 * @brief Checks if the number of database connections has reached a critical limit.
 	 *
 	 * @return bool Are more than 3/4 of the maximum connections used?
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	private static function maxConnectionsReached()
 	{
@@ -488,7 +469,9 @@ class Worker
 				$max = $r["Value"];
 			}
 			// Or it can be granted. This overrides the system variable
+			$stamp = (float)microtime(true);
 			$r = DBA::p('SHOW GRANTS');
+			self::$db_duration += (microtime(true) - $stamp);
 			while ($grants = DBA::fetch($r)) {
 				$grant = array_pop($grants);
 				if (stristr($grant, "GRANT USAGE ON")) {
@@ -503,16 +486,18 @@ class Worker
 		// If $max is set we will use the processlist to determine the current number of connections
 		// The processlist only shows entries of the current user
 		if ($max != 0) {
+			$stamp = (float)microtime(true);
 			$r = DBA::p('SHOW PROCESSLIST');
+			self::$db_duration += (microtime(true) - $stamp);
 			$used = DBA::numRows($r);
 			DBA::close($r);
 
-			logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
+			Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 
 			$level = ($used / $max) * 100;
 
 			if ($level >= $maxlevel) {
-				logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
+				Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 				return true;
 			}
 		}
@@ -535,37 +520,43 @@ class Worker
 		if ($used == 0) {
 			return false;
 		}
-		logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
+		Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 
 		$level = $used / $max * 100;
 
 		if ($level < $maxlevel) {
 			return false;
 		}
-		logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
+		Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 		return true;
 	}
 
 	/**
 	 * @brief fix the queue entry if the worker process died
 	 * @return void
+	 * @throws \Exception
 	 */
 	private static function killStaleWorkers()
 	{
+		$stamp = (float)microtime(true);
 		$entries = DBA::select(
 			'workerqueue',
 			['id', 'pid', 'executed', 'priority', 'parameter'],
-			['`executed` > ? AND NOT `done` AND `pid` != 0', DBA::NULL_DATETIME],
+			['NOT `done` AND `pid` != 0'],
 			['order' => ['priority', 'created']]
 		);
+		self::$db_duration += (microtime(true) - $stamp);
 
 		while ($entry = DBA::fetch($entries)) {
 			if (!posix_kill($entry["pid"], 0)) {
+				$stamp = (float)microtime(true);
 				DBA::update(
 					'workerqueue',
 					['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 					['id' => $entry["id"]]
 				);
+				self::$db_duration += (microtime(true) - $stamp);
+				self::$db_duration_write += (microtime(true) - $stamp);
 			} else {
 				// Kill long running processes
 				// Check if the priority is in a valid range
@@ -583,7 +574,7 @@ class Worker
 				// How long is the process already running?
 				$duration = (time() - strtotime($entry["executed"])) / 60;
 				if ($duration > $max_duration) {
-					logger("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
+					Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 					posix_kill($entry["pid"], SIGTERM);
 
 					// We killed the stale process.
@@ -597,13 +588,16 @@ class Worker
 					} elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 						$new_priority = PRIORITY_NEGLIGIBLE;
 					}
+					$stamp = (float)microtime(true);
 					DBA::update(
 						'workerqueue',
 						['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 						['id' => $entry["id"]]
 					);
+					self::$db_duration += (microtime(true) - $stamp);
+					self::$db_duration_write += (microtime(true) - $stamp);
 				} else {
-					logger("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
+					Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 				}
 			}
 		}
@@ -613,8 +607,9 @@ class Worker
 	 * @brief Checks if the number of active workers exceeds the given limits
 	 *
 	 * @return bool Are there too much workers running?
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function tooMuchWorkers()
+	private static function tooMuchWorkers()
 	{
 		$queues = Config::get("system", "worker_queues", 4);
 
@@ -638,63 +633,90 @@ class Worker
 
 			$processlist = '';
 
-			if (Config::get('system', 'worker_debug')) {
-				// Create a list of queue entries grouped by their priority
-				$listitem = [];
-
-				// Adding all processes with no workerqueue entry
-				$processes = DBA::p(
-					"SELECT COUNT(*) AS `running` FROM `process` WHERE NOT EXISTS
-							(SELECT id FROM `workerqueue`
-							WHERE `workerqueue`.`pid` = `process`.`pid` AND NOT `done` AND `pid` != ?)",
-					getmypid()
-				);
+			if (Config::get('system', 'worker_jpm')) {
+				$intervals = explode(',', Config::get('system', 'worker_jpm_range'));
+				$jobs_per_minute = [];
+				foreach ($intervals as $interval) {
+					if ($interval == 0) {
+						continue;
+					} else {
+						$interval = (int)$interval;
+					}
 
-				if ($process = DBA::fetch($processes)) {
-					$listitem[0] = "0:".$process["running"];
+					$stamp = (float)microtime(true);
+					$jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
+					self::$db_duration += (microtime(true) - $stamp);
+					self::$db_duration_stat += (microtime(true) - $stamp);
+					if ($job = DBA::fetch($jobs)) {
+						$jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
+					}
+					DBA::close($jobs);
 				}
-				DBA::close($processes);
+				$processlist = ' - jpm: '.implode('/', $jobs_per_minute);
+			}
+
+			// Create a list of queue entries grouped by their priority
+			$listitem = [0 => ''];
+
+			$idle_workers = $active;
+
+			$deferred = self::deferredEntries();
 
+			if (Config::get('system', 'worker_debug')) {
+				$waiting_processes = 0;
 				// Now adding all processes with workerqueue entries
-				$entries = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
-				while ($entry = DBA::fetch($entries)) {
-					$processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` WHERE `priority` = ?", $entry["priority"]);
+				$stamp = (float)microtime(true);
+				$jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` AND `next_try` < ? GROUP BY `priority`", DateTimeFormat::utcNow());
+				self::$db_duration += (microtime(true) - $stamp);
+				self::$db_duration_stat += (microtime(true) - $stamp);
+				while ($entry = DBA::fetch($jobs)) {
+					$stamp = (float)microtime(true);
+					$processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `priority` = ?", $entry["priority"]);
+					self::$db_duration += (microtime(true) - $stamp);
+					self::$db_duration_stat += (microtime(true) - $stamp);
 					if ($process = DBA::fetch($processes)) {
+						$idle_workers -= $process["running"];
+						$waiting_processes += $entry["entries"];
 						$listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 					}
 					DBA::close($processes);
 				}
-				DBA::close($entries);
+				DBA::close($jobs);
+				$entries = $deferred + $waiting_processes;
+			} else {
+				$entries = self::totalEntries();
+				$waiting_processes = max(0, $entries - $deferred);
+				$stamp = (float)microtime(true);
+				$jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` GROUP BY `priority` ORDER BY `priority`");
+				self::$db_duration += (microtime(true) - $stamp);
+				self::$db_duration_stat += (microtime(true) - $stamp);
 
-				$intervals = [1, 10, 60];
-				$jobs_per_minute = [];
-				foreach ($intervals as $interval) {
-					$jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ".intval($interval)." MINUTE");
-					if ($job = DBA::fetch($jobs)) {
-						$jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
-					}
-					DBA::close($jobs);
+				while ($entry = DBA::fetch($jobs)) {
+					$idle_workers -= $entry["running"];
+					$listitem[$entry["priority"]] = $entry["priority"].":".$entry["running"];
 				}
-				$processlist = ' - jpm: '.implode('/', $jobs_per_minute).' ('.implode(', ', $listitem).')';
+				DBA::close($jobs);
 			}
 
-			$entries = self::totalEntries();
+			$listitem[0] = "0:" . max(0, $idle_workers);
+
+			$processlist .= ' ('.implode(', ', $listitem).')';
 
-			if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($active >= $queues)) {
+			if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && self::entriesExists() && ($active >= $queues)) {
 				$top_priority = self::highestPriority();
 				$high_running = self::processWithPriorityActive($top_priority);
 
 				if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
-					logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
+					Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 					$queues = $active + 1;
 				}
 			}
 
-			logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries.$processlist." - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
+			Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 
 			// Are there fewer workers running as possible? Then fork a new one.
 			if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && ($entries > 1)) {
-				logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
+				Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 				if (Config::get('system', 'worker_daemon_mode', false)) {
 					self::IPCSetJobState(true);
 				} else {
@@ -715,192 +737,206 @@ class Worker
 	 * @brief Returns the number of active worker processes
 	 *
 	 * @return integer Number of active worker processes
+	 * @throws \Exception
 	 */
 	private static function activeWorkers()
 	{
-		return DBA::count('process', ['command' => 'Worker.php']);
+		$stamp = (float)microtime(true);
+		$count = DBA::count('process', ['command' => 'Worker.php']);
+		self::$db_duration += (microtime(true) - $stamp);
+		return $count;
 	}
 
 	/**
-	 * @brief Check if we should pass some slow processes
-	 *
-	 * When the active processes of the highest priority are using more than 2/3
-	 * of all processes, we let pass slower processes.
+	 * @brief Returns waiting jobs for the current process id
 	 *
-	 * @param string $highest_priority Returns the currently highest priority
-	 * @return bool We let pass a slower process than $highest_priority
+	 * @return array waiting workerqueue jobs
+	 * @throws \Exception
 	 */
-	private static function passingSlow(&$highest_priority)
+	private static function getWaitingJobForPID()
 	{
-		$highest_priority = 0;
-
-		$r = DBA::p(
-			"SELECT `priority`
-				FROM `process`
-				INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done`"
-		);
-
-		// No active processes at all? Fine
-		if (!DBA::isResult($r)) {
-			return false;
-		}
-		$priorities = [];
-		while ($line = DBA::fetch($r)) {
-			$priorities[] = $line["priority"];
+		$stamp = (float)microtime(true);
+		$r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
+		self::$db_duration += (microtime(true) - $stamp);
+		if (DBA::isResult($r)) {
+			return DBA::toArray($r);
 		}
 		DBA::close($r);
 
-		// Should not happen
-		if (count($priorities) == 0) {
-			return false;
-		}
-		$highest_priority = min($priorities);
+		return false;
+	}
 
-		// The highest process is already the slowest one?
-		// Then we quit
-		if ($highest_priority == PRIORITY_NEGLIGIBLE) {
-			return false;
+	/**
+	 * @brief Returns the next jobs that should be executed
+	 *
+	 * @return array array with next jobs
+	 * @throws \Exception
+	 */
+	private static function nextProcess()
+	{
+		$priority = self::nextPriority();
+		if (empty($priority)) {
+			Logger::info('No tasks found');
+			return [];
 		}
-		$high = 0;
-		foreach ($priorities as $priority) {
-			if ($priority == $highest_priority) {
-				++$high;
-			}
+
+		if ($priority <= PRIORITY_MEDIUM) {
+			$limit = Config::get('system', 'worker_fetch_limit', 1);
+		} else {
+			$limit = 1;
 		}
-		logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
-		$passing_slow = (($high/count($priorities)) > (2/3));
 
-		if ($passing_slow) {
-			logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
+		$ids = [];
+		$stamp = (float)microtime(true);
+		$condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
+		$tasks = DBA::select('workerqueue', ['id'], $condition, ['limit' => $limit, 'order' => ['created']]);
+		self::$db_duration += (microtime(true) - $stamp);
+		while ($task = DBA::fetch($tasks)) {
+			$ids[] = $task['id'];
 		}
-		return $passing_slow;
+		DBA::close($tasks);
+
+		Logger::info('Found:', ['id' => $ids, 'priority' => $priority]);
+		return $ids;
 	}
 
 	/**
-	 * @brief Find and claim the next worker process for us
+	 * @brief Returns the priority of the next workerqueue job
 	 *
-	 * @param boolean $passing_slow Returns if we had passed low priority processes
-	 * @return boolean Have we found something?
+	 * @return string priority
+	 * @throws \Exception
 	 */
-	private static function findWorkerProcesses(&$passing_slow)
+	private static function nextPriority()
 	{
-		$mypid = getmypid();
+		$waiting = [];
+		$priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
+		foreach ($priorities as $priority) {
+			$stamp = (float)microtime(true);
+			if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
+				$waiting[$priority] = true;
+			}
+			self::$db_duration += (microtime(true) - $stamp);
+		}
 
-		// Check if we should pass some low priority process
-		$highest_priority = 0;
-		$found = false;
-		$passing_slow = false;
+		if (!empty($waiting[PRIORITY_CRITICAL])) {
+			return PRIORITY_CRITICAL;
+		}
 
-		// The higher the number of parallel workers, the more we prefetch to prevent concurring access
-		// We decrease the limit with the number of entries left in the queue
-		$worker_queues = Config::get("system", "worker_queues", 4);
-		$queue_length = Config::get('system', 'worker_fetch_limit', 1);
-		$lower_job_limit = $worker_queues * $queue_length * 2;
-		$jobs = self::totalEntries();
+		$running = [];
+		$running_total = 0;
+		$stamp = (float)microtime(true);
+		$processes = DBA::p("SELECT COUNT(DISTINCT(`process`.`pid`)) AS `running`, `priority` FROM `process`
+			INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
+			WHERE NOT `done` GROUP BY `priority`");
+		self::$db_duration += (microtime(true) - $stamp);
+		while ($process = DBA::fetch($processes)) {
+			$running[$process['priority']] = $process['running'];
+			$running_total += $process['running'];
+		}
+		DBA::close($processes);
+
+		foreach ($priorities as $priority) {
+			if (!empty($waiting[$priority]) && empty($running[$priority])) {
+				Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
+				return $priority;
+			}
+		}
 
-		// Now do some magic
+		$active = max(self::activeWorkers(), $running_total);
+		$priorities = max(count($waiting), count($running));
 		$exponent = 2;
-		$slope = $queue_length / pow($lower_job_limit, $exponent);
-		$limit = min($queue_length, ceil($slope * pow($jobs, $exponent)));
 
-		logger('Total: '.$jobs.' - Maximum: '.$queue_length.' - jobs per queue: '.$limit, LOGGER_DEBUG);
-		$ids = [];
-		if (self::passingSlow($highest_priority)) {
-			// Are there waiting processes with a higher priority than the currently highest?
-			$result = DBA::select(
-				'workerqueue',
-				['id'],
-				["`executed` <= ? AND `priority` < ? AND NOT `done` AND `next_try` < ?",
-				DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
-				['limit' => $limit, 'order' => ['priority', 'created']]
-			);
+		$total = 0;
+		for ($i = 1; $i <= $priorities; ++$i) {
+			$total += pow($i, $exponent);
+		}
 
-			while ($id = DBA::fetch($result)) {
-				$ids[] = $id["id"];
+		$limit = [];
+		for ($i = 1; $i <= $priorities; ++$i) {
+			$limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
+		}
+
+		$i = 0;
+		foreach ($running as $priority => $workers) {
+			if ($workers < $limit[$i++]) {
+				Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
+				return $priority;
 			}
-			DBA::close($result);
+		}
 
-			$found = (count($ids) > 0);
+		if (!empty($waiting)) {
+			$priority = array_keys($waiting)[0];
+			Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
+			return $priority;
+		}
 
-			if (!$found) {
-				// Give slower processes some processing time
-				$result = DBA::select(
-					'workerqueue',
-					['id'],
-					["`executed` <= ? AND `priority` > ? AND NOT `done` AND `next_try` < ?",
-					DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
-					['limit' => $limit, 'order' => ['priority', 'created']]
-				);
+		return false;
+	}
 
-				while ($id = DBA::fetch($result)) {
-					$ids[] = $id["id"];
-				}
-				DBA::close($result);
+	/**
+	 * @brief Find and claim the next worker process for us
+	 *
+	 * @return boolean Have we found something?
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+	 */
+	private static function findWorkerProcesses()
+	{
+		$mypid = getmypid();
 
-				$found = (count($ids) > 0);
-				$passing_slow = $found;
-			}
-		}
+		$ids = self::nextProcess();
 
-		// If there is no result (or we shouldn't pass lower processes) we check without priority limit
-		if (!$found) {
-			$result = DBA::select(
-				'workerqueue',
-				['id'],
-				["`executed` <= ? AND NOT `done` AND `next_try` < ?",
-				DBA::NULL_DATETIME, DateTimeFormat::utcNow()],
-				['limit' => $limit, 'order' => ['priority', 'created']]
-			);
+		// If there is no result we check without priority limit
+		if (empty($ids)) {
+			$stamp = (float)microtime(true);
+			$condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
+			$result = DBA::select('workerqueue', ['id'], $condition, ['limit' => 1, 'order' => ['priority', 'created']]);
+			self::$db_duration += (microtime(true) - $stamp);
 
 			while ($id = DBA::fetch($result)) {
 				$ids[] = $id["id"];
 			}
 			DBA::close($result);
-
-			$found = (count($ids) > 0);
 		}
 
-		if ($found) {
-			$condition = "`id` IN (".substr(str_repeat("?, ", count($ids)), 0, -2).") AND `pid` = 0 AND NOT `done`";
-			array_unshift($ids, $condition);
-			DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $ids);
+		if (!empty($ids)) {
+			$stamp = (float)microtime(true);
+			$condition = ['id' => $ids, 'done' => false, 'pid' => 0];
+			DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $condition);
+			self::$db_duration += (microtime(true) - $stamp);
+			self::$db_duration_write += (microtime(true) - $stamp);
 		}
 
-		return $found;
+		return !empty($ids);
 	}
 
 	/**
 	 * @brief Returns the next worker process
 	 *
-	 * @param boolean $passing_slow Returns if we had passed low priority processes
 	 * @return string SQL statement
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function workerProcess(&$passing_slow)
+	public static function workerProcess()
 	{
-		$stamp = (float)microtime(true);
-
 		// There can already be jobs for us in the queue.
-		$r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
-		if (DBA::isResult($r)) {
-			self::$db_duration += (microtime(true) - $stamp);
-			return DBA::toArray($r);
+		$waiting = self::getWaitingJobForPID();
+		if (!empty($waiting)) {
+			return $waiting;
 		}
-		DBA::close($r);
 
 		$stamp = (float)microtime(true);
 		if (!Lock::acquire('worker_process')) {
 			return false;
 		}
-		self::$lock_duration = (microtime(true) - $stamp);
+		self::$lock_duration += (microtime(true) - $stamp);
 
-		$stamp = (float)microtime(true);
-		$found = self::findWorkerProcesses($passing_slow);
-		self::$db_duration += (microtime(true) - $stamp);
+		$found = self::findWorkerProcesses();
 
 		Lock::release('worker_process');
 
 		if ($found) {
+			$stamp = (float)microtime(true);
 			$r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
+			self::$db_duration += (microtime(true) - $stamp);
 			return DBA::toArray($r);
 		}
 		return false;
@@ -909,17 +945,22 @@ class Worker
 	/**
 	 * @brief Removes a workerqueue entry from the current process
 	 * @return void
+	 * @throws \Exception
 	 */
 	public static function unclaimProcess()
 	{
 		$mypid = getmypid();
 
+		$stamp = (float)microtime(true);
 		DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
+		self::$db_duration += (microtime(true) - $stamp);
+		self::$db_duration_write += (microtime(true) - $stamp);
 	}
 
 	/**
 	 * @brief Call the front end worker
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function callWorker()
 	{
@@ -934,6 +975,7 @@ class Worker
 	/**
 	 * @brief Call the front end worker if there aren't any active
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function executeIfIdle()
 	{
@@ -962,7 +1004,7 @@ class Worker
 
 			self::runCron();
 
-			logger('Call worker', LOGGER_DEBUG);
+			Logger::log('Call worker', Logger::DEBUG);
 			self::spawnWorker();
 			return;
 		}
@@ -984,30 +1026,35 @@ class Worker
 	/**
 	 * @brief Removes long running worker processes
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function clearProcesses()
 	{
 		$timeout = Config::get("system", "frontend_worker_timeout", 10);
 
 		/// @todo We should clean up the corresponding workerqueue entries as well
+		$stamp = (float)microtime(true);
 		$condition = ["`created` < ? AND `command` = 'worker.php'",
 				DateTimeFormat::utc("now - ".$timeout." minutes")];
 		DBA::delete('process', $condition);
+		self::$db_duration = (microtime(true) - $stamp);
+		self::$db_duration_write += (microtime(true) - $stamp);
 	}
 
 	/**
 	 * @brief Runs the cron processes
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	private static function runCron()
 	{
-		logger('Add cron entries', LOGGER_DEBUG);
+		Logger::log('Add cron entries', Logger::DEBUG);
 
 		// Check for spooled items
-		self::add(PRIORITY_HIGH, "SpoolPost");
+		self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
 
 		// Run the cron job that calls all other jobs
-		self::add(PRIORITY_MEDIUM, "Cron");
+		self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
 
 		// Cleaning dead processes
 		self::killStaleWorkers();
@@ -1015,7 +1062,9 @@ class Worker
 
 	/**
 	 * @brief Spawns a new worker
+	 * @param bool $do_cron
 	 * @return void
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function spawnWorker($do_cron = false)
 	{
@@ -1040,12 +1089,13 @@ class Worker
 	 * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
 	 * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
 	 *
+	 * @return boolean "false" if proc_run couldn't be executed
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @note $cmd and string args are surrounded with ""
 	 *
 	 * @hooks 'proc_run'
-	 * 	array $arr
+	 *    array $arr
 	 *
-	 * @return boolean "false" if proc_run couldn't be executed
 	 */
 	public static function add($cmd)
 	{
@@ -1057,7 +1107,7 @@ class Worker
 
 		$arr = ['args' => $args, 'run_cmd' => true];
 
-		Addon::callHooks("proc_run", $arr);
+		Hook::callAll("proc_run", $arr);
 		if (!$arr['run_cmd'] || !count($args)) {
 			return true;
 		}
@@ -1065,6 +1115,7 @@ class Worker
 		$priority = PRIORITY_MEDIUM;
 		$dont_fork = Config::get("system", "worker_dont_fork", false);
 		$created = DateTimeFormat::utcNow();
+		$force_priority = false;
 
 		$run_parameter = array_shift($args);
 
@@ -1080,6 +1131,9 @@ class Worker
 			if (isset($run_parameter['dont_fork'])) {
 				$dont_fork = $run_parameter['dont_fork'];
 			}
+			if (isset($run_parameter['force_priority'])) {
+				$force_priority = $run_parameter['force_priority'];
+			}
 		}
 
 		$parameters = json_encode($args);
@@ -1092,6 +1146,8 @@ class Worker
 
 		if (!$found) {
 			DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
+		} elseif ($force_priority) {
+			DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
 		}
 
 		// Should we quit and wait for the worker to be called as a cronjob?
@@ -1137,9 +1193,10 @@ class Worker
 
 		$retrial = $queue['retrial'];
 		$id = $queue['id'];
+		$priority = $queue['priority'];
 
 		if ($retrial > 14) {
-			logger('Id ' . $id . ' had been tried 14 times. We stop now.', LOGGER_DEBUG);
+			Logger::log('Id ' . $id . ' had been tried 14 times. We stop now.', Logger::DEBUG);
 			return;
 		}
 
@@ -1147,10 +1204,21 @@ class Worker
 		$delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
 		$next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
 
-		logger('Defer execution ' . $retrial . ' of id ' . $id . ' to ' . $next, LOGGER_DEBUG);
+		if (($priority < PRIORITY_MEDIUM) && ($retrial > 2)) {
+			$priority = PRIORITY_MEDIUM;
+		} elseif (($priority < PRIORITY_LOW) && ($retrial > 5)) {
+			$priority = PRIORITY_LOW;
+		} elseif (($priority < PRIORITY_NEGLIGIBLE) && ($retrial > 7)) {
+			$priority = PRIORITY_NEGLIGIBLE;
+		}
+
+		Logger::log('Defer execution ' . $retrial . ' of id ' . $id . ' to ' . $next . ' - priority old/new: ' . $queue['priority'] . '/' . $priority, Logger::DEBUG);
 
-		$fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0];
+		$stamp = (float)microtime(true);
+		$fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
 		DBA::update('workerqueue', $fields, ['id' => $id]);
+		self::$db_duration += (microtime(true) - $stamp);
+		self::$db_duration_write += (microtime(true) - $stamp);
 	}
 
 	/**
@@ -1174,6 +1242,7 @@ class Worker
 	 *
 	 * @brief Remove the active process from the "process" table
 	 * @return bool
+	 * @throws \Exception
 	 */
 	public static function endProcess()
 	{
@@ -1185,10 +1254,14 @@ class Worker
 	 *
 	 * @brief Set the flag if some job is waiting
 	 * @param boolean $jobs Is there a waiting job?
+	 * @throws \Exception
 	 */
 	public static function IPCSetJobState($jobs)
 	{
+		$stamp = (float)microtime(true);
 		DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
+		self::$db_duration += (microtime(true) - $stamp);
+		self::$db_duration_write += (microtime(true) - $stamp);
 	}
 
 	/**
@@ -1196,10 +1269,13 @@ class Worker
 	 *
 	 * @brief Checks if some worker job waits to be executed
 	 * @return bool
+	 * @throws \Exception
 	 */
 	public static function IPCJobsExists()
 	{
+		$stamp = (float)microtime(true);
 		$row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
+		self::$db_duration += (microtime(true) - $stamp);
 
 		// When we don't have a row, no job is running
 		if (!DBA::isResult($row)) {