]> git.mxchange.org Git - friendica.git/blobdiff - src/Core/Worker.php
Merge remote-tracking branch 'upstream/2019.03-RC' into worker2
[friendica.git] / src / Core / Worker.php
index 77e38532c828b6dd92faefe7586af25864eb3744..b0b9fc2cf2d9f3d00a509e17b269cc6befa53797 100644 (file)
@@ -5,14 +5,12 @@
 namespace Friendica\Core;
 
 use Friendica\BaseObject;
-use Friendica\Core\Logger;
 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
  *
@@ -25,25 +23,33 @@ require_once 'include/dba.php';
 class Worker
 {
        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 $mode = 0;
 
        /**
         * @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::log('Pre check: maximum load reached, quitting.', LOGGER_DEBUG);
+                       Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
                        return;
                }
 
@@ -59,25 +65,25 @@ class Worker
 
                // Count active workers and compare them with a maximum value that depends on the load
                if (self::tooMuchWorkers()) {
-                       Logger::log('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::log('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::log('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::log('Pre check: maximum processes reached, quitting.', LOGGER_DEBUG);
+                       Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
                        return;
                }
 
@@ -87,56 +93,52 @@ class Worker
                }
 
                $starttime = time();
+               self::$mode = 1;
 
                // 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::log('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) - $stamp);
+                               if (!self::getWaitingJobForPID() && Lock::acquire('worker_process', 0)) {
+                                       self::findWorkerProcesses();
                                        Lock::release('worker_process');
+                                       self::$mode = 3;
                                }
                        }
 
+                       self::$mode = 4;
+
+                       // Quit the worker once every cron interval
+                       if (time() > ($starttime + Config::get('system', 'cron_interval'))) {
+                               Logger::log('Process lifetime reached, quitting.', Logger::DEBUG);
+                               return;
+                       }
+
                        // 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::log('Active worker limit reached, quitting.', LOGGER_DEBUG);
+                                       Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
                                        Lock::release('worker');
                                        return;
                                }
 
                                // Check free memory
                                if ($a->isMinMemoryReached()) {
-                                       Logger::log('Memory limit reached, quitting.', LOGGER_DEBUG);
+                                       Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
                                        Lock::release('worker');
                                        return;
                                }
                                Lock::release('worker');
-                               self::$db_duration += (microtime(true) - $stamp);
-                       }
-
-                       // Quit the worker once every 5 minutes
-                       if (time() > ($starttime + 300)) {
-                               Logger::log('Process lifetime reached, quitting.', LOGGER_DEBUG);
-                               return;
                        }
                }
 
@@ -144,40 +146,65 @@ class Worker
                if (Config::get('system', 'worker_daemon_mode', false)) {
                        self::IPCSetJobState(false);
                }
-               Logger::log("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()
        {
-               return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` > ?",
-                       DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
+               $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 {
@@ -191,11 +218,11 @@ 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);
        }
 
@@ -205,28 +232,29 @@ 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::log("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 ($a->isMaxProcessesReached()) {
-                       Logger::log("Max processes reached for process ".$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::log("Max connection reached for process ".$mypid, LOGGER_DEBUG);
+                       Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
                        return false;
                }
 
@@ -248,6 +276,7 @@ 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($argv);
@@ -255,12 +284,12 @@ class Worker
                        self::execFunction($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;
                }
@@ -272,7 +301,10 @@ class Worker
 
                if (!validate_include($include)) {
                        Logger::log("Include file ".$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;
                }
 
@@ -293,6 +325,7 @@ 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, $argv, false);
@@ -302,9 +335,13 @@ class Worker
                                Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
                        }
                        self::$db_duration = (microtime(true) - $stamp);
+                       self::$db_duration_write += (microtime(true) - $stamp);
                } else {
                        Logger::log("Function ".$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;
@@ -318,164 +355,87 @@ 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::log("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::$up_start = microtime(true);
-
                /* With these values we can analyze how effective the worker is.
                 * The database and rest time should be low since this is the unproductive time.
                 * The execution time is the productive time.
                 * By changing parameters like the maximum number of workers we can check the effectivness.
                */
-               Logger::log(
-                       'DB: '.number_format(self::$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);
+
+               $logger->info('Performance log.', ['mode' => self::$mode, '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::$mode = 2;
 
                if ($duration > 3600) {
-                       Logger::log("Prio ".$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 ($duration > 600) {
-                       Logger::log("Prio ".$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 ($duration > 300) {
-                       Logger::log("Prio ".$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 ($duration > 120) {
-                       Logger::log("Prio ".$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::log("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::log(
-                               "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 ($cooldown > 0) {
-                       Logger::log("Process ".$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);
                }
        }
@@ -484,6 +444,7 @@ 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()
        {
@@ -500,7 +461,9 @@ 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")) {
@@ -515,11 +478,13 @@ 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::log("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
+                       Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 
                        $level = ($used / $max) * 100;
 
@@ -547,7 +512,7 @@ class Worker
                if ($used == 0) {
                        return false;
                }
-               Logger::log("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
+               Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 
                $level = $used / $max * 100;
 
@@ -561,23 +526,29 @@ class Worker
        /**
         * @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) - $stamp);
                        } else {
                                // Kill long running processes
                                // Check if the priority is in a valid range
@@ -609,13 +580,16 @@ class Worker
                                        } elseif ($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) - $stamp);
                                } else {
-                                       Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
+                                       Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
                                }
                        }
                }
@@ -625,8 +599,9 @@ 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);
 
@@ -650,64 +625,90 @@ 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();
-                       $deferred = self::deferredEntries();
+                       $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) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
-                                       Logger::log("There are jobs with priority ".$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::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $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)) && ($entries > 1)) {
-                               Logger::log("Active workers: ".$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 {
@@ -728,193 +729,206 @@ 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 {
+                       $limit = 1;
                }
-               Logger::log("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
-               $passing_slow = (($high/count($priorities)) > (2/3));
 
-               if ($passing_slow) {
-                       Logger::log("Passing slower processes than priority ".$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();
-               $deferred = self::deferredEntries();
+               $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::log('Deferred: ' . $deferred . ' - 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;
@@ -923,17 +937,22 @@ 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()
        {
@@ -948,6 +967,7 @@ 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()
        {
@@ -976,7 +996,7 @@ class Worker
 
                        self::runCron();
 
-                       Logger::log('Call worker', LOGGER_DEBUG);
+                       Logger::log('Call worker', Logger::DEBUG);
                        self::spawnWorker();
                        return;
                }
@@ -998,30 +1018,35 @@ 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::log('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();
@@ -1029,7 +1054,9 @@ 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)
        {
@@ -1054,12 +1081,13 @@ 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)
        {
@@ -1071,7 +1099,7 @@ 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;
                }
@@ -1079,6 +1107,7 @@ 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);
 
@@ -1094,6 +1123,9 @@ 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);
@@ -1106,6 +1138,8 @@ 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?
@@ -1151,9 +1185,10 @@ class Worker
 
                $retrial = $queue['retrial'];
                $id = $queue['id'];
+               $priority = $queue['priority'];
 
                if ($retrial > 14) {
-                       Logger::log('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;
                }
 
@@ -1161,10 +1196,21 @@ class Worker
                $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
                $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
 
-               Logger::log('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);
        }
 
        /**
@@ -1188,6 +1234,7 @@ class Worker
         *
         * @brief Remove the active process from the "process" table
         * @return bool
+        * @throws \Exception
         */
        public static function endProcess()
        {
@@ -1199,10 +1246,14 @@ 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);
        }
 
        /**
@@ -1210,10 +1261,13 @@ 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)) {