]> git.mxchange.org Git - friendica.git/blobdiff - src/Core/Worker.php
Merge pull request #6219 from MrPetovan/task/remove-x
[friendica.git] / src / Core / Worker.php
index bafe3711301c66b0074562be934dac9a231d1db6..f3736d2573f7e10fbe4f934b42d434577380e7e3 100644 (file)
@@ -4,15 +4,12 @@
  */
 namespace Friendica\Core;
 
-use Friendica\Core\Addon;
-use Friendica\Core\Config;
-use Friendica\Core\System;
-use Friendica\Database\DBM;
+use Friendica\BaseObject;
+use Friendica\Core\Logger;
+use Friendica\Database\DBA;
 use Friendica\Model\Process;
 use Friendica\Util\DateTimeFormat;
-use Friendica\Util\Lock;
 use Friendica\Util\Network;
-use dba;
 
 require_once 'include/dba.php';
 
@@ -45,8 +42,8 @@ class Worker
                self::$up_start = microtime(true);
 
                // At first check the maximum load. We shouldn't continue with a high load
-               if ($a->maxload_reached()) {
-                       logger('Pre check: maximum load reached, quitting.', LOGGER_DEBUG);
+               if ($a->isMaxLoadReached()) {
+                       Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
                        return;
                }
 
@@ -62,25 +59,25 @@ 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 ($a->min_memory_reached()) {
-                       logger('Pre check: Memory limit reached, quitting.', LOGGER_DEBUG);
+               if ($a->isMinMemoryReached()) {
+                       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 ($a->max_processes_reached()) {
-                       logger('Pre check: maximum processes reached, quitting.', LOGGER_DEBUG);
+               if ($a->isMaxProcessesReached()) {
+                       Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
                        return;
                }
 
@@ -103,40 +100,42 @@ class Worker
 
                                // 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 (!$refetched && Lock::set('worker_process', 0)) {
+                               if (!$refetched && Lock::acquire('worker_process', 0)) {
                                        $stamp = (float)microtime(true);
                                        $refetched = self::findWorkerProcesses($passing_slow);
                                        self::$db_duration += (microtime(true) - $stamp);
-                                       Lock::remove('worker_process');
+                                       Lock::release('worker_process');
                                }
                        }
 
                        // To avoid the quitting of multiple workers only one worker at a time will execute the check
-                       if (Lock::set('worker', 0)) {
+                       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 ($a->min_memory_reached()) {
-                                       logger('Memory limit reached, quitting.', LOGGER_DEBUG);
+                               if ($a->isMinMemoryReached()) {
+                                       Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
+                                       Lock::release('worker');
                                        return;
                                }
-                               Lock::remove('worker');
+                               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);
+                               Logger::log('Process lifetime reached, quitting.', Logger::DEBUG);
                                return;
                        }
                }
@@ -145,7 +144,18 @@ class Worker
                if (Config::get('system', 'worker_daemon_mode', false)) {
                        self::IPCSetJobState(false);
                }
-               logger("Couldn't select a workerqueue entry, quitting.", LOGGER_DEBUG);
+               Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
+       }
+
+       /**
+        * @brief Returns the number of deferred entries in the worker queue
+        *
+        * @return integer Number of deferred entries in the worker queue
+        */
+       private static function deferredEntries()
+       {
+               return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` > ?",
+                       DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
        }
 
        /**
@@ -155,7 +165,8 @@ class Worker
         */
        private static function totalEntries()
        {
-               return dba::count('workerqueue', ["`executed` <= ? AND NOT `done`", NULL_DATE]);
+               return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` < ?",
+                       DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
        }
 
        /**
@@ -165,9 +176,9 @@ class Worker
         */
        private static function highestPriority()
        {
-               $condition = ["`executed` <= ? AND NOT `done`", NULL_DATE];
-               $workerqueue = dba::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
-               if (DBM::is_result($workerqueue)) {
+               $condition = ["`executed` <= ? AND NOT `done` AND `next_try` < ?", DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
+               $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
+               if (DBA::isResult($workerqueue)) {
                        return $workerqueue["priority"];
                } else {
                        return 0;
@@ -183,8 +194,9 @@ class Worker
         */
        private static function processWithPriorityActive($priority)
        {
-               $condition = ["`priority` <= ? AND `executed` > ? AND NOT `done`", $priority, NULL_DATE];
-               return dba::exists('workerqueue', $condition);
+               $condition = ["`priority` <= ? AND `executed` > ? AND NOT `done` AND `next_try` < ?",
+                       $priority, DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
+               return DBA::exists('workerqueue', $condition);
        }
 
        /**
@@ -202,19 +214,19 @@ class Worker
 
                // 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 ($a->max_processes_reached()) {
-                       logger("Max processes reached for process ".$mypid, LOGGER_DEBUG);
+               if ($a->isMaxProcessesReached()) {
+                       Logger::log("Max processes reached for process ".$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;
                }
 
@@ -234,7 +246,7 @@ class Worker
 
                        if ($age > 1) {
                                $stamp = (float)microtime(true);
-                               dba::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
+                               DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
                                self::$db_duration += (microtime(true) - $stamp);
                        }
 
@@ -243,7 +255,9 @@ class Worker
                        self::execFunction($queue, $include, $argv, true);
 
                        $stamp = (float)microtime(true);
-                       if (dba::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
+
+                       $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);
@@ -257,8 +271,8 @@ class Worker
                }
 
                if (!validate_include($include)) {
-                       logger("Include file ".$argv[0]." is not valid!");
-                       dba::delete('workerqueue', ['id' => $queue["id"]]);
+                       Logger::log("Include file ".$argv[0]." is not valid!");
+                       DBA::delete('workerqueue', ['id' => $queue["id"]]);
                        return true;
                }
 
@@ -277,20 +291,20 @@ class Worker
 
                        if ($age > 1) {
                                $stamp = (float)microtime(true);
-                               dba::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
+                               DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
                                self::$db_duration += (microtime(true) - $stamp);
                        }
 
                        self::execFunction($queue, $funcname, $argv, false);
 
                        $stamp = (float)microtime(true);
-                       if (dba::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
+                       if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
                                Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
                        }
                        self::$db_duration = (microtime(true) - $stamp);
                } else {
-                       logger("Function ".$funcname." does not exist");
-                       dba::delete('workerqueue', ['id' => $queue["id"]]);
+                       Logger::log("Function ".$funcname." does not exist");
+                       DBA::delete('workerqueue', ['id' => $queue["id"]]);
                }
 
                return true;
@@ -313,9 +327,9 @@ class Worker
 
                $argc = count($argv);
 
-               $new_process_id = uniqid("wrk", true);
+               $new_process_id = System::processID("wrk");
 
-               logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
+               Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
 
                $stamp = (float)microtime(true);
 
@@ -356,7 +370,7 @@ class Worker
                $a->process_id = $old_process_id;
                unset($a->queue);
 
-               $duration = number_format(microtime(true) - $stamp, 3);
+               $duration = (microtime(true) - $stamp);
 
                self::$up_start = microtime(true);
 
@@ -365,27 +379,27 @@ class Worker
                 * The execution time is the productive time.
                 * By changing parameters like the maximum number of workers we can check the effectivness.
                */
-               logger(
+               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
+                       Logger::DEBUG
                );
 
                self::$lock_duration = 0;
 
                if ($duration > 3600) {
-                       logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", LOGGER_DEBUG);
+                       Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", Logger::DEBUG);
                } elseif ($duration > 600) {
-                       logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+                       Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", Logger::DEBUG);
                } elseif ($duration > 300) {
-                       logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+                       Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", Logger::DEBUG);
                } elseif ($duration > 120) {
-                       logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+                       Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", Logger::DEBUG);
                }
 
-               logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds. Process PID: ".$new_process_id);
+               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")) {
@@ -440,7 +454,7 @@ class Worker
                                }
                        }
 
-                       logger(
+                       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),
@@ -454,14 +468,14 @@ class Worker
                                                + $a->performance["network"] + $a->performance["file"]), 2),
                                        number_format($duration, 2)
                                ),
-                               LOGGER_DEBUG
+                               Logger::DEBUG
                        );
                }
 
                $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::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
                        sleep($cooldown);
                }
        }
@@ -481,13 +495,13 @@ class Worker
 
                if ($max == 0) {
                        // the maximum number of possible user connections can be a system variable
-                       $r = dba::fetch_first("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
-                       if (DBM::is_result($r)) {
+                       $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
+                       if (DBA::isResult($r)) {
                                $max = $r["Value"];
                        }
                        // Or it can be granted. This overrides the system variable
-                       $r = dba::p('SHOW GRANTS');
-                       while ($grants = dba::fetch($r)) {
+                       $r = DBA::p('SHOW GRANTS');
+                       while ($grants = DBA::fetch($r)) {
                                $grant = array_pop($grants);
                                if (stristr($grant, "GRANT USAGE ON")) {
                                        if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
@@ -495,52 +509,52 @@ class Worker
                                        }
                                }
                        }
-                       dba::close($r);
+                       DBA::close($r);
                }
 
                // 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) {
-                       $r = dba::p('SHOW PROCESSLIST');
-                       $used = dba::num_rows($r);
-                       dba::close($r);
+                       $r = DBA::p('SHOW PROCESSLIST');
+                       $used = DBA::numRows($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;
                        }
                }
 
                // We will now check for the system values.
                // This limit could be reached although the user limits are fine.
-               $r = dba::fetch_first("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
-               if (!DBM::is_result($r)) {
+               $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
+               if (!DBA::isResult($r)) {
                        return false;
                }
                $max = intval($r["Value"]);
                if ($max == 0) {
                        return false;
                }
-               $r = dba::fetch_first("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
-               if (!DBM::is_result($r)) {
+               $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
+               if (!DBA::isResult($r)) {
                        return false;
                }
                $used = intval($r["Value"]);
                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;
        }
 
@@ -550,18 +564,18 @@ class Worker
         */
        private static function killStaleWorkers()
        {
-               $entries = dba::select(
+               $entries = DBA::select(
                        'workerqueue',
                        ['id', 'pid', 'executed', 'priority', 'parameter'],
-                       ['`executed` > ? AND NOT `done` AND `pid` != 0', NULL_DATE],
+                       ['`executed` > ? AND NOT `done` AND `pid` != 0', DBA::NULL_DATETIME],
                        ['order' => ['priority', 'created']]
                );
 
-               while ($entry = dba::fetch($entries)) {
+               while ($entry = DBA::fetch($entries)) {
                        if (!posix_kill($entry["pid"], 0)) {
-                               dba::update(
+                               DBA::update(
                                        'workerqueue',
-                                       ['executed' => NULL_DATE, 'pid' => 0],
+                                       ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
                                        ['id' => $entry["id"]]
                                );
                        } else {
@@ -581,7 +595,7 @@ class Worker
                                // How long is the process already running?
                                $duration = (time() - strtotime($entry["executed"])) / 60;
                                if ($duration > $max_duration) {
-                                       logger("Worker process ".$entry["pid"]." (".implode(" ", $argv).") took more than ".$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.
@@ -595,13 +609,13 @@ class Worker
                                        } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
                                                $new_priority = PRIORITY_NEGLIGIBLE;
                                        }
-                                       dba::update(
+                                       DBA::update(
                                                'workerqueue',
-                                               ['executed' => NULL_DATE, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
+                                               ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
                                                ['id' => $entry["id"]]
                                        );
                                } else {
-                                       logger("Worker process ".$entry["pid"]." (".implode(" ", $argv).") now runs for ".round($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);
                                }
                        }
                }
@@ -621,16 +635,16 @@ class Worker
                $active = self::activeWorkers();
 
                // Decrease the number of workers at higher load
-               $load = current_load();
+               $load = System::currentLoad();
                if ($load) {
                        $maxsysload = intval(Config::get("system", "maxloadavg", 50));
 
-                       if (Config::get('system', 'worker_linear_load', false)) {
-                               $exponent = 1;
-                       } else {
-                               $exponent = 3;
-                       }
-
+                       /* Default exponent 3 causes queues to rapidly decrease as load increases.
+                        * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
+                        * For some environments, this rapid decrease is not needed.
+                        * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
+                        */
+                       $exponent = intval(Config::get('system', 'worker_load_exponent', 3));
                        $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
                        $queues = intval(ceil($slope * $maxqueues));
 
@@ -641,58 +655,60 @@ class Worker
                                $listitem = [];
 
                                // Adding all processes with no workerqueue entry
-                               $processes = dba::p(
+                               $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 ($process = dba::fetch($processes)) {
+                               if ($process = DBA::fetch($processes)) {
                                        $listitem[0] = "0:".$process["running"];
                                }
-                               dba::close($processes);
+                               DBA::close($processes);
 
                                // 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` = ?", $entry["priority"]);
-                                       if ($process = dba::fetch($processes)) {
+                               $entries = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` AND `next_try` < ? GROUP BY `priority`", DateTimeFormat::utcNow());
+                               while ($entry = DBA::fetch($entries)) {
+                                       $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `next_try` < ? AND `priority` = ?",
+                                               DateTimeFormat::utcNow(), $entry["priority"]);
+                                       if ($process = DBA::fetch($processes)) {
                                                $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
                                        }
-                                       dba::close($processes);
+                                       DBA::close($processes);
                                }
-                               dba::close($entries);
+                               DBA::close($entries);
 
                                $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)) {
+                                       $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ".intval($interval)." MINUTE");
+                                       if ($job = DBA::fetch($jobs)) {
                                                $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
                                        }
-                                       dba::close($jobs);
+                                       DBA::close($jobs);
                                }
                                $processlist = ' - jpm: '.implode('/', $jobs_per_minute).' ('.implode(', ', $listitem).')';
                        }
 
                        $entries = self::totalEntries();
+                       $deferred = self::deferredEntries();
 
                        if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($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 . "/" . $entries . $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 {
@@ -716,7 +732,7 @@ class Worker
         */
        private static function activeWorkers()
        {
-               return dba::count('process', ['command' => 'Worker.php']);
+               return DBA::count('process', ['command' => 'Worker.php']);
        }
 
        /**
@@ -732,21 +748,21 @@ class Worker
        {
                $highest_priority = 0;
 
-               $r = dba::p(
+               $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 (!DBM::is_result($r)) {
+               if (!DBA::isResult($r)) {
                        return false;
                }
                $priorities = [];
-               while ($line = dba::fetch($r)) {
+               while ($line = DBA::fetch($r)) {
                        $priorities[] = $line["priority"];
                }
-               dba::close($r);
+               DBA::close($r);
 
                // Should not happen
                if (count($priorities) == 0) {
@@ -765,11 +781,11 @@ class Worker
                                ++$high;
                        }
                }
-               logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
+               Logger::log("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, Logger::DEBUG);
                $passing_slow = (($high/count($priorities)) > (2/3));
 
                if ($passing_slow) {
-                       logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
+                       Logger::log("Passing slower processes than priority ".$highest_priority, Logger::DEBUG);
                }
                return $passing_slow;
        }
@@ -795,43 +811,46 @@ class Worker
                $queue_length = Config::get('system', 'worker_fetch_limit', 1);
                $lower_job_limit = $worker_queues * $queue_length * 2;
                $jobs = self::totalEntries();
+               $deferred = self::deferredEntries();
 
                // Now do some magic
                $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);
+               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(
+                       $result = DBA::select(
                                'workerqueue',
                                ['id'],
-                               ["`executed` <= ? AND `priority` < ? AND NOT `done`", NULL_DATE, $highest_priority],
+                               ["`executed` <= ? AND `priority` < ? AND NOT `done` AND `next_try` < ?",
+                               DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
                                ['limit' => $limit, 'order' => ['priority', 'created']]
                        );
 
-                       while ($id = dba::fetch($result)) {
+                       while ($id = DBA::fetch($result)) {
                                $ids[] = $id["id"];
                        }
-                       dba::close($result);
+                       DBA::close($result);
 
                        $found = (count($ids) > 0);
 
                        if (!$found) {
                                // Give slower processes some processing time
-                               $result = dba::select(
+                               $result = DBA::select(
                                        'workerqueue',
                                        ['id'],
-                                       ["`executed` <= ? AND `priority` > ? AND NOT `done`", NULL_DATE, $highest_priority],
+                                       ["`executed` <= ? AND `priority` > ? AND NOT `done` AND `next_try` < ?",
+                                       DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
                                        ['limit' => $limit, 'order' => ['priority', 'created']]
                                );
 
-                               while ($id = dba::fetch($result)) {
+                               while ($id = DBA::fetch($result)) {
                                        $ids[] = $id["id"];
                                }
-                               dba::close($result);
+                               DBA::close($result);
 
                                $found = (count($ids) > 0);
                                $passing_slow = $found;
@@ -840,17 +859,18 @@ class Worker
 
                // If there is no result (or we shouldn't pass lower processes) we check without priority limit
                if (!$found) {
-                       $result = dba::select(
+                       $result = DBA::select(
                                'workerqueue',
                                ['id'],
-                               ["`executed` <= ? AND NOT `done`", NULL_DATE],
+                               ["`executed` <= ? AND NOT `done` AND `next_try` < ?",
+                               DBA::NULL_DATETIME, DateTimeFormat::utcNow()],
                                ['limit' => $limit, 'order' => ['priority', 'created']]
                        );
 
-                       while ($id = dba::fetch($result)) {
+                       while ($id = DBA::fetch($result)) {
                                $ids[] = $id["id"];
                        }
-                       dba::close($result);
+                       DBA::close($result);
 
                        $found = (count($ids) > 0);
                }
@@ -858,7 +878,7 @@ class Worker
                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);
+                       DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $ids);
                }
 
                return $found;
@@ -875,15 +895,15 @@ class Worker
                $stamp = (float)microtime(true);
 
                // There can already be jobs for us in the queue.
-               $r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
-               if (DBM::is_result($r)) {
+               $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
+               if (DBA::isResult($r)) {
                        self::$db_duration += (microtime(true) - $stamp);
-                       return dba::inArray($r);
+                       return DBA::toArray($r);
                }
-               dba::close($r);
+               DBA::close($r);
 
                $stamp = (float)microtime(true);
-               if (!Lock::set('worker_process')) {
+               if (!Lock::acquire('worker_process')) {
                        return false;
                }
                self::$lock_duration = (microtime(true) - $stamp);
@@ -892,11 +912,11 @@ class Worker
                $found = self::findWorkerProcesses($passing_slow);
                self::$db_duration += (microtime(true) - $stamp);
 
-               Lock::remove('worker_process');
+               Lock::release('worker_process');
 
                if ($found) {
-                       $r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
-                       return dba::inArray($r);
+                       $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
+                       return DBA::toArray($r);
                }
                return false;
        }
@@ -909,7 +929,7 @@ class Worker
        {
                $mypid = getmypid();
 
-               dba::update('workerqueue', ['executed' => NULL_DATE, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
+               DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
        }
 
        /**
@@ -957,7 +977,7 @@ class Worker
 
                        self::runCron();
 
-                       logger('Call worker', LOGGER_DEBUG);
+                       Logger::log('Call worker', Logger::DEBUG);
                        self::spawnWorker();
                        return;
                }
@@ -987,7 +1007,7 @@ class Worker
                /// @todo We should clean up the corresponding workerqueue entries as well
                $condition = ["`created` < ? AND `command` = 'worker.php'",
                                DateTimeFormat::utc("now - ".$timeout." minutes")];
-               dba::delete('process', $condition);
+               DBA::delete('process', $condition);
        }
 
        /**
@@ -996,7 +1016,7 @@ class Worker
         */
        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");
@@ -1014,13 +1034,11 @@ class Worker
         */
        public static function spawnWorker($do_cron = false)
        {
-               $args = ["bin/worker.php"];
+               $command = 'bin/worker.php';
 
-               if (!$do_cron) {
-                       $args[] = "no_cron";
-               }
+               $args = ['no_cron' => !$do_cron];
 
-               get_app()->proc_run($args);
+               get_app()->proc_run($command, $args);
 
                // after spawning we have to remove the flag.
                if (Config::get('system', 'worker_daemon_mode', false)) {
@@ -1080,15 +1098,15 @@ class Worker
                }
 
                $parameters = json_encode($args);
-               $found = dba::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
+               $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
 
                // Quit if there was a database error - a precaution for the update process to 3.5.3
-               if (dba::errorNo() != 0) {
+               if (DBA::errorNo() != 0) {
                        return false;
                }
 
                if (!$found) {
-                       dba::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
+                       DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
                }
 
                // Should we quit and wait for the worker to be called as a cronjob?
@@ -1097,13 +1115,13 @@ class Worker
                }
 
                // If there is a lock then we don't have to check for too much worker
-               if (!Lock::set('worker', 0)) {
+               if (!Lock::acquire('worker', 0)) {
                        return true;
                }
 
                // If there are already enough workers running, don't fork another one
                $quit = self::tooMuchWorkers();
-               Lock::remove('worker');
+               Lock::release('worker');
 
                if ($quit) {
                        return true;
@@ -1121,6 +1139,35 @@ class Worker
                return true;
        }
 
+       /**
+        * Defers the current worker entry
+        */
+       public static function defer()
+       {
+               if (empty(BaseObject::getApp()->queue)) {
+                       return;
+               }
+
+               $queue = BaseObject::getApp()->queue;
+
+               $retrial = $queue['retrial'];
+               $id = $queue['id'];
+
+               if ($retrial > 14) {
+                       Logger::log('Id ' . $id . ' had been tried 14 times. We stop now.', Logger::DEBUG);
+                       return;
+               }
+
+               // Calculate the delay until the next trial
+               $delay = (($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);
+
+               $fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0];
+               DBA::update('workerqueue', $fields, ['id' => $id]);
+       }
+
        /**
         * Log active processes into the "process" table
         *
@@ -1156,7 +1203,7 @@ class Worker
         */
        public static function IPCSetJobState($jobs)
        {
-               dba::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
+               DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
        }
 
        /**
@@ -1167,10 +1214,10 @@ class Worker
         */
        public static function IPCJobsExists()
        {
-               $row = dba::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
+               $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
 
                // When we don't have a row, no job is running
-               if (!DBM::is_result($row)) {
+               if (!DBA::isResult($row)) {
                        return false;
                }