src/Core/Worker.php

   1 <?php
   2 /**
   3  * @file src/Core/Worker.php
   4  */
   5 namespace Friendica\Core;
   6
   7 use Friendica\BaseObject;
   8 use Friendica\Database\DBA;
   9 use Friendica\Model\Process;
  10 use Friendica\Util\DateTimeFormat;
  11 use Friendica\Util\Logger\WorkerLogger;
  12 use Friendica\Util\Network;
  13
  14 /**
  15  * @file src/Core/Worker.php
  16  *
  17  * @brief Contains the class for the worker background job processing
  18  */
  19
  20 /**
  21  * @brief Worker methods
  22  */
  23 class Worker
  24 {
  25         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
  26         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
  27         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
  28         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
  29
  30         private static $up_start;
  31         private static $db_duration = 0;
  32         private static $db_duration_count = 0;
  33         private static $db_duration_write = 0;
  34         private static $db_duration_stat = 0;
  35         private static $lock_duration = 0;
  36         private static $last_update;
  37         private static $state;
  38
  39         /**
  40          * @brief Processes the tasks that are in the workerqueue table
  41          *
  42          * @param boolean $run_cron Should the cron processes be executed?
  43          * @return void
  44          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  45          */
  46         public static function processQueue($run_cron = true)
  47         {
  48                 $a = \get_app();
  49
  50                 // Ensure that all "strtotime" operations do run timezone independent
  51                 date_default_timezone_set('UTC');
  52
  53                 self::$up_start = microtime(true);
  54
  55                 // At first check the maximum load. We shouldn't continue with a high load
  56                 if ($a->isMaxLoadReached()) {
  57                         Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
  58                         return;
  59                 }
  60
  61                 // We now start the process. This is done after the load check since this could increase the load.
  62                 self::startProcess();
  63
  64                 // Kill stale processes every 5 minutes
  65                 $last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
  66                 if (time() > ($last_cleanup + 300)) {
  67                         Config::set('system', 'worker_last_cleaned', time());
  68                         self::killStaleWorkers();
  69                 }
  70
  71                 // Count active workers and compare them with a maximum value that depends on the load
  72                 if (self::tooMuchWorkers()) {
  73                         Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
  74                         return;
  75                 }
  76
  77                 // Do we have too few memory?
  78                 if ($a->isMinMemoryReached()) {
  79                         Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
  80                         return;
  81                 }
  82
  83                 // Possibly there are too much database connections
  84                 if (self::maxConnectionsReached()) {
  85                         Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
  86                         return;
  87                 }
  88
  89                 // Possibly there are too much database processes that block the system
  90                 if ($a->isMaxProcessesReached()) {
  91                         Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
  92                         return;
  93                 }
  94
  95                 // Now we start additional cron processes if we should do so
  96                 if ($run_cron) {
  97                         self::runCron();
  98                 }
  99
 100                 $starttime = time();
 101                 self::$state = self::STATE_STARTUP;
 102
 103                 // We fetch the next queue entry that is about to be executed
 104                 while ($r = self::workerProcess()) {
 105                         $refetched = false;
 106                         foreach ($r as $entry) {
 107                                 // Assure that the priority is an integer value
 108                                 $entry['priority'] = (int)$entry['priority'];
 109
 110                                 // The work will be done
 111                                 if (!self::execute($entry)) {
 112                                         Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 113                                         return;
 114                                 }
 115
 116                                 // Trying to fetch new processes - but only once when successful
 117                                 if (!$refetched && Lock::acquire('worker_process', 0)) {
 118                                         self::findWorkerProcesses();
 119                                         Lock::release('worker_process');
 120                                         self::$state = self::STATE_REFETCH;
 121                                         $refetched = true;
 122                                 } else {
 123                                         self::$state = self::STATE_SHORT_LOOP;
 124                                 }
 125                         }
 126
 127                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 128                         if (!self::getWaitingJobForPID()) {
 129                                 self::$state = self::STATE_LONG_LOOP;
 130
 131                                 if (Lock::acquire('worker', 0)) {
 132                                 // Count active workers and compare them with a maximum value that depends on the load
 133                                         if (self::tooMuchWorkers()) {
 134                                                 Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 135                                                 Lock::release('worker');
 136                                                 return;
 137                                         }
 138
 139                                         // Check free memory
 140                                         if ($a->isMinMemoryReached()) {
 141                                                 Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 142                                                 Lock::release('worker');
 143                                                 return;
 144                                         }
 145                                         Lock::release('worker');
 146                                 }
 147                         }
 148
 149                         // Quit the worker once every cron interval
 150                         if (time() > ($starttime + (Config::get('system', 'cron_interval') * 60))) {
 151                                 Logger::info('Process lifetime reached, respawning.');
 152                                 self::spawnWorker();
 153                                 return;
 154                         }
 155                 }
 156
 157                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 158                 if (Config::get('system', 'worker_daemon_mode', false)) {
 159                         self::IPCSetJobState(false);
 160                 }
 161                 Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
 162         }
 163
 164         /**
 165          * @brief Check if non executed tasks do exist in the worker queue
 166          *
 167          * @return boolean Returns "true" if tasks are existing
 168          * @throws \Exception
 169          */
 170         private static function entriesExists()
 171         {
 172                 $stamp = (float)microtime(true);
 173                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 174                 self::$db_duration += (microtime(true) - $stamp);
 175                 return $exists;
 176         }
 177
 178         /**
 179          * @brief Returns the number of deferred entries in the worker queue
 180          *
 181          * @return integer Number of deferred entries in the worker queue
 182          * @throws \Exception
 183          */
 184         private static function deferredEntries()
 185         {
 186                 $stamp = (float)microtime(true);
 187                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` > ?", DateTimeFormat::utcNow()]);
 188                 self::$db_duration += (microtime(true) - $stamp);
 189                 self::$db_duration_count += (microtime(true) - $stamp);
 190                 return $count;
 191         }
 192
 193         /**
 194          * @brief Returns the number of non executed entries in the worker queue
 195          *
 196          * @return integer Number of non executed entries in the worker queue
 197          * @throws \Exception
 198          */
 199         private static function totalEntries()
 200         {
 201                 $stamp = (float)microtime(true);
 202                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 203                 self::$db_duration += (microtime(true) - $stamp);
 204                 self::$db_duration_count += (microtime(true) - $stamp);
 205                 return $count;
 206         }
 207
 208         /**
 209          * @brief Returns the highest priority in the worker queue that isn't executed
 210          *
 211          * @return integer Number of active worker processes
 212          * @throws \Exception
 213          */
 214         private static function highestPriority()
 215         {
 216                 $stamp = (float)microtime(true);
 217                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 218                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 219                 self::$db_duration += (microtime(true) - $stamp);
 220                 if (DBA::isResult($workerqueue)) {
 221                         return $workerqueue["priority"];
 222                 } else {
 223                         return 0;
 224                 }
 225         }
 226
 227         /**
 228          * @brief Returns if a process with the given priority is running
 229          *
 230          * @param integer $priority The priority that should be checked
 231          *
 232          * @return integer Is there a process running with that priority?
 233          * @throws \Exception
 234          */
 235         private static function processWithPriorityActive($priority)
 236         {
 237                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 238                 return DBA::exists('workerqueue', $condition);
 239         }
 240
 241         /**
 242          * @brief Execute a worker entry
 243          *
 244          * @param array $queue Workerqueue entry
 245          *
 246          * @return boolean "true" if further processing should be stopped
 247          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 248          */
 249         public static function execute($queue)
 250         {
 251                 $a = \get_app();
 252
 253                 $mypid = getmypid();
 254
 255                 // Quit when in maintenance
 256                 if (Config::get('system', 'maintenance', false, true)) {
 257                         Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 258                         return false;
 259                 }
 260
 261                 // Constantly check the number of parallel database processes
 262                 if ($a->isMaxProcessesReached()) {
 263                         Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 264                         return false;
 265                 }
 266
 267                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 268                 if (self::maxConnectionsReached()) {
 269                         Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 270                         return false;
 271                 }
 272
 273                 $argv = json_decode($queue["parameter"], true);
 274
 275                 // Check for existance and validity of the include file
 276                 $include = $argv[0];
 277
 278                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 279                         // We constantly update the "executed" date every minute to avoid being killed too soon
 280                         if (!isset(self::$last_update)) {
 281                                 self::$last_update = strtotime($queue["executed"]);
 282                         }
 283
 284                         $age = (time() - self::$last_update) / 60;
 285                         self::$last_update = time();
 286
 287                         if ($age > 1) {
 288                                 $stamp = (float)microtime(true);
 289                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 290                                 self::$db_duration += (microtime(true) - $stamp);
 291                                 self::$db_duration_write += (microtime(true) - $stamp);
 292                         }
 293
 294                         array_shift($argv);
 295
 296                         self::execFunction($queue, $include, $argv, true);
 297
 298                         $stamp = (float)microtime(true);
 299                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 300                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 301                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 302                         }
 303                         self::$db_duration = (microtime(true) - $stamp);
 304                         self::$db_duration_write += (microtime(true) - $stamp);
 305
 306                         return true;
 307                 }
 308
 309                 // The script could be provided as full path or only with the function name
 310                 if ($include == basename($include)) {
 311                         $include = "include/".$include.".php";
 312                 }
 313
 314                 if (!validate_include($include)) {
 315                         Logger::log("Include file ".$argv[0]." is not valid!");
 316                         $stamp = (float)microtime(true);
 317                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 318                         self::$db_duration = (microtime(true) - $stamp);
 319                         self::$db_duration_write += (microtime(true) - $stamp);
 320                         return true;
 321                 }
 322
 323                 require_once $include;
 324
 325                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 326
 327                 if (function_exists($funcname)) {
 328                         // We constantly update the "executed" date every minute to avoid being killed too soon
 329                         if (!isset(self::$last_update)) {
 330                                 self::$last_update = strtotime($queue["executed"]);
 331                         }
 332
 333                         $age = (time() - self::$last_update) / 60;
 334                         self::$last_update = time();
 335
 336                         if ($age > 1) {
 337                                 $stamp = (float)microtime(true);
 338                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 339                                 self::$db_duration += (microtime(true) - $stamp);
 340                                 self::$db_duration_write += (microtime(true) - $stamp);
 341                         }
 342
 343                         self::execFunction($queue, $funcname, $argv, false);
 344
 345                         $stamp = (float)microtime(true);
 346                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 347                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 348                         }
 349                         self::$db_duration = (microtime(true) - $stamp);
 350                         self::$db_duration_write += (microtime(true) - $stamp);
 351                 } else {
 352                         Logger::log("Function ".$funcname." does not exist");
 353                         $stamp = (float)microtime(true);
 354                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 355                         self::$db_duration = (microtime(true) - $stamp);
 356                         self::$db_duration_write += (microtime(true) - $stamp);
 357                 }
 358
 359                 return true;
 360         }
 361
 362         /**
 363          * @brief Execute a function from the queue
 364          *
 365          * @param array   $queue       Workerqueue entry
 366          * @param string  $funcname    name of the function
 367          * @param array   $argv        Array of values to be passed to the function
 368          * @param boolean $method_call boolean
 369          * @return void
 370          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 371          */
 372         private static function execFunction($queue, $funcname, $argv, $method_call)
 373         {
 374                 $a = \get_app();
 375
 376                 $argc = count($argv);
 377
 378                 $logger = $a->getLogger();
 379                 $workerLogger = new WorkerLogger($logger, $funcname);
 380
 381                 $workerLogger ->info("Process start.", ['priority' => $queue["priority"], 'id' => $queue["id"]]);
 382
 383                 $stamp = (float)microtime(true);
 384
 385                 // We use the callstack here to analyze the performance of executed worker entries.
 386                 // For this reason the variables have to be initialized.
 387                 $a->getProfiler()->reset();
 388
 389                 $a->queue = $queue;
 390
 391                 $up_duration = microtime(true) - self::$up_start;
 392
 393                 // Reset global data to avoid interferences
 394                 unset($_SESSION);
 395
 396                 // Set the workerLogger as new default logger
 397                 Logger::init($workerLogger);
 398                 if ($method_call) {
 399                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 400                 } else {
 401                         $funcname($argv, $argc);
 402                 }
 403                 Logger::init($logger);
 404
 405                 unset($a->queue);
 406
 407                 $duration = (microtime(true) - $stamp);
 408
 409                 /* With these values we can analyze how effective the worker is.
 410                  * The database and rest time should be low since this is the unproductive time.
 411                  * The execution time is the productive time.
 412                  * By changing parameters like the maximum number of workers we can check the effectivness.
 413                 */
 414                 $dbtotal = round(self::$db_duration, 2);
 415                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 416                 $dbcount = round(self::$db_duration_count, 2);
 417                 $dbstat  = round(self::$db_duration_stat, 2);
 418                 $dbwrite = round(self::$db_duration_write, 2);
 419                 $dblock  = round(self::$lock_duration, 2);
 420                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 421                 $exec    = round($duration, 2);
 422
 423                 $logger->info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 424
 425                 self::$up_start = microtime(true);
 426                 self::$db_duration = 0;
 427                 self::$db_duration_count = 0;
 428                 self::$db_duration_stat = 0;
 429                 self::$db_duration_write = 0;
 430                 self::$lock_duration = 0;
 431
 432                 if ($duration > 3600) {
 433                         $logger->info('Longer than 1 hour.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 434                 } elseif ($duration > 600) {
 435                         $logger->info('Longer than 10 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 436                 } elseif ($duration > 300) {
 437                         $logger->info('Longer than 5 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 438                 } elseif ($duration > 120) {
 439                         $logger->info('Longer than 2 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 440                 }
 441
 442                 $workerLogger->info('Process done.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration, 3)]);
 443
 444                 $a->getProfiler()->saveLog($a->getLogger(), "ID " . $queue["id"] . ": " . $funcname);
 445
 446                 $cooldown = Config::get("system", "worker_cooldown", 0);
 447
 448                 if ($cooldown > 0) {
 449                         $logger->info('Cooldown.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'cooldown' => $cooldown]);
 450                         sleep($cooldown);
 451                 }
 452         }
 453
 454         /**
 455          * @brief Checks if the number of database connections has reached a critical limit.
 456          *
 457          * @return bool Are more than 3/4 of the maximum connections used?
 458          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 459          */
 460         private static function maxConnectionsReached()
 461         {
 462                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 463                 $max = Config::get("system", "max_connections");
 464
 465                 // Fetch the percentage level where the worker will get active
 466                 $maxlevel = Config::get("system", "max_connections_level", 75);
 467
 468                 if ($max == 0) {
 469                         // the maximum number of possible user connections can be a system variable
 470                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 471                         if (DBA::isResult($r)) {
 472                                 $max = $r["Value"];
 473                         }
 474                         // Or it can be granted. This overrides the system variable
 475                         $stamp = (float)microtime(true);
 476                         $r = DBA::p('SHOW GRANTS');
 477                         self::$db_duration += (microtime(true) - $stamp);
 478                         while ($grants = DBA::fetch($r)) {
 479                                 $grant = array_pop($grants);
 480                                 if (stristr($grant, "GRANT USAGE ON")) {
 481                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 482                                                 $max = $match[1];
 483                                         }
 484                                 }
 485                         }
 486                         DBA::close($r);
 487                 }
 488
 489                 // If $max is set we will use the processlist to determine the current number of connections
 490                 // The processlist only shows entries of the current user
 491                 if ($max != 0) {
 492                         $stamp = (float)microtime(true);
 493                         $r = DBA::p('SHOW PROCESSLIST');
 494                         self::$db_duration += (microtime(true) - $stamp);
 495                         $used = DBA::numRows($r);
 496                         DBA::close($r);
 497
 498                         Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 499
 500                         $level = ($used / $max) * 100;
 501
 502                         if ($level >= $maxlevel) {
 503                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 504                                 return true;
 505                         }
 506                 }
 507
 508                 // We will now check for the system values.
 509                 // This limit could be reached although the user limits are fine.
 510                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 511                 if (!DBA::isResult($r)) {
 512                         return false;
 513                 }
 514                 $max = intval($r["Value"]);
 515                 if ($max == 0) {
 516                         return false;
 517                 }
 518                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 519                 if (!DBA::isResult($r)) {
 520                         return false;
 521                 }
 522                 $used = intval($r["Value"]);
 523                 if ($used == 0) {
 524                         return false;
 525                 }
 526                 Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 527
 528                 $level = $used / $max * 100;
 529
 530                 if ($level < $maxlevel) {
 531                         return false;
 532                 }
 533                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 534                 return true;
 535         }
 536
 537         /**
 538          * @brief fix the queue entry if the worker process died
 539          * @return void
 540          * @throws \Exception
 541          */
 542         private static function killStaleWorkers()
 543         {
 544                 $stamp = (float)microtime(true);
 545                 $entries = DBA::select(
 546                         'workerqueue',
 547                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 548                         ['NOT `done` AND `pid` != 0'],
 549                         ['order' => ['priority', 'created']]
 550                 );
 551                 self::$db_duration += (microtime(true) - $stamp);
 552
 553                 while ($entry = DBA::fetch($entries)) {
 554                         if (!posix_kill($entry["pid"], 0)) {
 555                                 $stamp = (float)microtime(true);
 556                                 DBA::update(
 557                                         'workerqueue',
 558                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 559                                         ['id' => $entry["id"]]
 560                                 );
 561                                 self::$db_duration += (microtime(true) - $stamp);
 562                                 self::$db_duration_write += (microtime(true) - $stamp);
 563                         } else {
 564                                 // Kill long running processes
 565                                 // Check if the priority is in a valid range
 566                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 567                                         $entry["priority"] = PRIORITY_MEDIUM;
 568                                 }
 569
 570                                 // Define the maximum durations
 571                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 572                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 573
 574                                 $argv = json_decode($entry["parameter"], true);
 575                                 $argv[0] = basename($argv[0]);
 576
 577                                 // How long is the process already running?
 578                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 579                                 if ($duration > $max_duration) {
 580                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 581                                         posix_kill($entry["pid"], SIGTERM);
 582
 583                                         // We killed the stale process.
 584                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 585                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 586                                         $new_priority = $entry["priority"];
 587                                         if ($entry["priority"] == PRIORITY_HIGH) {
 588                                                 $new_priority = PRIORITY_MEDIUM;
 589                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 590                                                 $new_priority = PRIORITY_LOW;
 591                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 592                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 593                                         }
 594                                         $stamp = (float)microtime(true);
 595                                         DBA::update(
 596                                                 'workerqueue',
 597                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 598                                                 ['id' => $entry["id"]]
 599                                         );
 600                                         self::$db_duration += (microtime(true) - $stamp);
 601                                         self::$db_duration_write += (microtime(true) - $stamp);
 602                                 } else {
 603                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 604                                 }
 605                         }
 606                 }
 607         }
 608
 609         /**
 610          * @brief Checks if the number of active workers exceeds the given limits
 611          *
 612          * @return bool Are there too much workers running?
 613          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 614          */
 615         private static function tooMuchWorkers()
 616         {
 617                 $queues = Config::get("system", "worker_queues", 10);
 618
 619                 $maxqueues = $queues;
 620
 621                 $active = self::activeWorkers();
 622
 623                 // Decrease the number of workers at higher load
 624                 $load = System::currentLoad();
 625                 if ($load) {
 626                         $maxsysload = intval(Config::get("system", "maxloadavg", 20));
 627
 628                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 629                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 630                          * For some environments, this rapid decrease is not needed.
 631                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 632                          */
 633                         $exponent = intval(Config::get('system', 'worker_load_exponent', 3));
 634                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 635                         $queues = intval(ceil($slope * $maxqueues));
 636
 637                         $processlist = '';
 638
 639                         if (Config::get('system', 'worker_jpm')) {
 640                                 $intervals = explode(',', Config::get('system', 'worker_jpm_range'));
 641                                 $jobs_per_minute = [];
 642                                 foreach ($intervals as $interval) {
 643                                         if ($interval == 0) {
 644                                                 continue;
 645                                         } else {
 646                                                 $interval = (int)$interval;
 647                                         }
 648
 649                                         $stamp = (float)microtime(true);
 650                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
 651                                         self::$db_duration += (microtime(true) - $stamp);
 652                                         self::$db_duration_stat += (microtime(true) - $stamp);
 653                                         if ($job = DBA::fetch($jobs)) {
 654                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 655                                         }
 656                                         DBA::close($jobs);
 657                                 }
 658                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 659                         }
 660
 661                         // Create a list of queue entries grouped by their priority
 662                         $listitem = [0 => ''];
 663
 664                         $idle_workers = $active;
 665
 666                         $deferred = self::deferredEntries();
 667
 668                         if (Config::get('system', 'worker_debug')) {
 669                                 $waiting_processes = 0;
 670                                 // Now adding all processes with workerqueue entries
 671                                 $stamp = (float)microtime(true);
 672                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` AND `next_try` < ? GROUP BY `priority`", DateTimeFormat::utcNow());
 673                                 self::$db_duration += (microtime(true) - $stamp);
 674                                 self::$db_duration_stat += (microtime(true) - $stamp);
 675                                 while ($entry = DBA::fetch($jobs)) {
 676                                         $stamp = (float)microtime(true);
 677                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `priority` = ?", $entry["priority"]);
 678                                         self::$db_duration += (microtime(true) - $stamp);
 679                                         self::$db_duration_stat += (microtime(true) - $stamp);
 680                                         if ($process = DBA::fetch($processes)) {
 681                                                 $idle_workers -= $process["running"];
 682                                                 $waiting_processes += $entry["entries"];
 683                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 684                                         }
 685                                         DBA::close($processes);
 686                                 }
 687                                 DBA::close($jobs);
 688                                 $entries = $deferred + $waiting_processes;
 689                         } else {
 690                                 $entries = self::totalEntries();
 691                                 $waiting_processes = max(0, $entries - $deferred);
 692                                 $stamp = (float)microtime(true);
 693                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` GROUP BY `priority` ORDER BY `priority`");
 694                                 self::$db_duration += (microtime(true) - $stamp);
 695                                 self::$db_duration_stat += (microtime(true) - $stamp);
 696
 697                                 while ($entry = DBA::fetch($jobs)) {
 698                                         $idle_workers -= $entry["running"];
 699                                         $listitem[$entry["priority"]] = $entry["priority"].":".$entry["running"];
 700                                 }
 701                                 DBA::close($jobs);
 702                         }
 703
 704                         $listitem[0] = "0:" . max(0, $idle_workers);
 705
 706                         $processlist .= ' ('.implode(', ', $listitem).')';
 707
 708                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 709                                 $top_priority = self::highestPriority();
 710                                 $high_running = self::processWithPriorityActive($top_priority);
 711
 712                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 713                                         Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 714                                         $queues = $active + 1;
 715                                 }
 716                         }
 717
 718                         Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 719
 720                         // Are there fewer workers running as possible? Then fork a new one.
 721                         if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && self::entriesExists()) {
 722                                 Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 723                                 if (Config::get('system', 'worker_daemon_mode', false)) {
 724                                         self::IPCSetJobState(true);
 725                                 } else {
 726                                         self::spawnWorker();
 727                                 }
 728                         }
 729                 }
 730
 731                 // if there are too much worker, we don't spawn a new one.
 732                 if (Config::get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 733                         self::IPCSetJobState(false);
 734                 }
 735
 736                 return $active > $queues;
 737         }
 738
 739         /**
 740          * @brief Returns the number of active worker processes
 741          *
 742          * @return integer Number of active worker processes
 743          * @throws \Exception
 744          */
 745         private static function activeWorkers()
 746         {
 747                 $stamp = (float)microtime(true);
 748                 $count = DBA::count('process', ['command' => 'Worker.php']);
 749                 self::$db_duration += (microtime(true) - $stamp);
 750                 return $count;
 751         }
 752
 753         /**
 754          * @brief Returns waiting jobs for the current process id
 755          *
 756          * @return array waiting workerqueue jobs
 757          * @throws \Exception
 758          */
 759         private static function getWaitingJobForPID()
 760         {
 761                 $stamp = (float)microtime(true);
 762                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 763                 self::$db_duration += (microtime(true) - $stamp);
 764                 if (DBA::isResult($r)) {
 765                         return DBA::toArray($r);
 766                 }
 767                 DBA::close($r);
 768
 769                 return false;
 770         }
 771
 772         /**
 773          * @brief Returns the next jobs that should be executed
 774          *
 775          * @return array array with next jobs
 776          * @throws \Exception
 777          */
 778         private static function nextProcess()
 779         {
 780                 $priority = self::nextPriority();
 781                 if (empty($priority)) {
 782                         Logger::info('No tasks found');
 783                         return [];
 784                 }
 785
 786                 if ($priority <= PRIORITY_MEDIUM) {
 787                         $limit = Config::get('system', 'worker_fetch_limit', 1);
 788                 } else {
 789                         $limit = 1;
 790                 }
 791
 792                 $ids = [];
 793                 $stamp = (float)microtime(true);
 794                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 795                 $tasks = DBA::select('workerqueue', ['id'], $condition, ['limit' => $limit, 'order' => ['created']]);
 796                 self::$db_duration += (microtime(true) - $stamp);
 797                 while ($task = DBA::fetch($tasks)) {
 798                         $ids[] = $task['id'];
 799                 }
 800                 DBA::close($tasks);
 801
 802                 Logger::info('Found:', ['id' => $ids, 'priority' => $priority]);
 803                 return $ids;
 804         }
 805
 806         /**
 807          * @brief Returns the priority of the next workerqueue job
 808          *
 809          * @return string priority
 810          * @throws \Exception
 811          */
 812         private static function nextPriority()
 813         {
 814                 $waiting = [];
 815                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
 816                 foreach ($priorities as $priority) {
 817                         $stamp = (float)microtime(true);
 818                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 819                                 $waiting[$priority] = true;
 820                         }
 821                         self::$db_duration += (microtime(true) - $stamp);
 822                 }
 823
 824                 if (!empty($waiting[PRIORITY_CRITICAL])) {
 825                         return PRIORITY_CRITICAL;
 826                 }
 827
 828                 $running = [];
 829                 $running_total = 0;
 830                 $stamp = (float)microtime(true);
 831                 $processes = DBA::p("SELECT COUNT(DISTINCT(`process`.`pid`)) AS `running`, `priority` FROM `process`
 832                         INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
 833                         WHERE NOT `done` GROUP BY `priority`");
 834                 self::$db_duration += (microtime(true) - $stamp);
 835                 while ($process = DBA::fetch($processes)) {
 836                         $running[$process['priority']] = $process['running'];
 837                         $running_total += $process['running'];
 838                 }
 839                 DBA::close($processes);
 840
 841                 foreach ($priorities as $priority) {
 842                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 843                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 844                                 return $priority;
 845                         }
 846                 }
 847
 848                 $active = max(self::activeWorkers(), $running_total);
 849                 $priorities = max(count($waiting), count($running));
 850                 $exponent = 2;
 851
 852                 $total = 0;
 853                 for ($i = 1; $i <= $priorities; ++$i) {
 854                         $total += pow($i, $exponent);
 855                 }
 856
 857                 $limit = [];
 858                 for ($i = 1; $i <= $priorities; ++$i) {
 859                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 860                 }
 861
 862                 $i = 0;
 863                 foreach ($running as $priority => $workers) {
 864                         if ($workers < $limit[$i++]) {
 865                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 866                                 return $priority;
 867                         }
 868                 }
 869
 870                 if (!empty($waiting)) {
 871                         $priority = array_keys($waiting)[0];
 872                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
 873                         return $priority;
 874                 }
 875
 876                 return false;
 877         }
 878
 879         /**
 880          * @brief Find and claim the next worker process for us
 881          *
 882          * @return boolean Have we found something?
 883          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 884          */
 885         private static function findWorkerProcesses()
 886         {
 887                 $mypid = getmypid();
 888
 889                 $ids = self::nextProcess();
 890
 891                 // If there is no result we check without priority limit
 892                 if (empty($ids)) {
 893                         $stamp = (float)microtime(true);
 894                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 895                         $result = DBA::select('workerqueue', ['id'], $condition, ['limit' => 1, 'order' => ['priority', 'created']]);
 896                         self::$db_duration += (microtime(true) - $stamp);
 897
 898                         while ($id = DBA::fetch($result)) {
 899                                 $ids[] = $id["id"];
 900                         }
 901                         DBA::close($result);
 902                 }
 903
 904                 if (!empty($ids)) {
 905                         $stamp = (float)microtime(true);
 906                         $condition = ['id' => $ids, 'done' => false, 'pid' => 0];
 907                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $condition);
 908                         self::$db_duration += (microtime(true) - $stamp);
 909                         self::$db_duration_write += (microtime(true) - $stamp);
 910                 }
 911
 912                 return !empty($ids);
 913         }
 914
 915         /**
 916          * @brief Returns the next worker process
 917          *
 918          * @return string SQL statement
 919          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 920          */
 921         public static function workerProcess()
 922         {
 923                 // There can already be jobs for us in the queue.
 924                 $waiting = self::getWaitingJobForPID();
 925                 if (!empty($waiting)) {
 926                         return $waiting;
 927                 }
 928
 929                 $stamp = (float)microtime(true);
 930                 if (!Lock::acquire('worker_process')) {
 931                         return false;
 932                 }
 933                 self::$lock_duration += (microtime(true) - $stamp);
 934
 935                 $found = self::findWorkerProcesses();
 936
 937                 Lock::release('worker_process');
 938
 939                 if ($found) {
 940                         $stamp = (float)microtime(true);
 941                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 942                         self::$db_duration += (microtime(true) - $stamp);
 943                         return DBA::toArray($r);
 944                 }
 945                 return false;
 946         }
 947
 948         /**
 949          * @brief Removes a workerqueue entry from the current process
 950          * @return void
 951          * @throws \Exception
 952          */
 953         public static function unclaimProcess()
 954         {
 955                 $mypid = getmypid();
 956
 957                 $stamp = (float)microtime(true);
 958                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 959                 self::$db_duration += (microtime(true) - $stamp);
 960                 self::$db_duration_write += (microtime(true) - $stamp);
 961         }
 962
 963         /**
 964          * @brief Call the front end worker
 965          * @return void
 966          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 967          */
 968         public static function callWorker()
 969         {
 970                 if (!Config::get("system", "frontend_worker")) {
 971                         return;
 972                 }
 973
 974                 $url = System::baseUrl()."/worker";
 975                 Network::fetchUrl($url, false, $redirects, 1);
 976         }
 977
 978         /**
 979          * @brief Call the front end worker if there aren't any active
 980          * @return void
 981          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 982          */
 983         public static function executeIfIdle()
 984         {
 985                 if (!Config::get("system", "frontend_worker")) {
 986                         return;
 987                 }
 988
 989                 // Do we have "proc_open"? Then we can fork the worker
 990                 if (function_exists("proc_open")) {
 991                         // When was the last time that we called the worker?
 992                         // Less than one minute? Then we quit
 993                         if ((time() - Config::get("system", "worker_started")) < 60) {
 994                                 return;
 995                         }
 996
 997                         Config::set("system", "worker_started", time());
 998
 999                         // Do we have enough running workers? Then we quit here.
1000                         if (self::tooMuchWorkers()) {
1001                                 // Cleaning dead processes
1002                                 self::killStaleWorkers();
1003                                 Process::deleteInactive();
1004
1005                                 return;
1006                         }
1007
1008                         self::runCron();
1009
1010                         Logger::log('Call worker', Logger::DEBUG);
1011                         self::spawnWorker();
1012                         return;
1013                 }
1014
1015                 // We cannot execute background processes.
1016                 // We now run the processes from the frontend.
1017                 // This won't work with long running processes.
1018                 self::runCron();
1019
1020                 self::clearProcesses();
1021
1022                 $workers = self::activeWorkers();
1023
1024                 if ($workers == 0) {
1025                         self::callWorker();
1026                 }
1027         }
1028
1029         /**
1030          * @brief Removes long running worker processes
1031          * @return void
1032          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1033          */
1034         public static function clearProcesses()
1035         {
1036                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
1037
1038                 /// @todo We should clean up the corresponding workerqueue entries as well
1039                 $stamp = (float)microtime(true);
1040                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1041                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1042                 DBA::delete('process', $condition);
1043                 self::$db_duration = (microtime(true) - $stamp);
1044                 self::$db_duration_write += (microtime(true) - $stamp);
1045         }
1046
1047         /**
1048          * @brief Runs the cron processes
1049          * @return void
1050          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1051          */
1052         private static function runCron()
1053         {
1054                 Logger::log('Add cron entries', Logger::DEBUG);
1055
1056                 // Check for spooled items
1057                 self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
1058
1059                 // Run the cron job that calls all other jobs
1060                 self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
1061
1062                 // Cleaning dead processes
1063                 self::killStaleWorkers();
1064         }
1065
1066         /**
1067          * @brief Spawns a new worker
1068          * @param bool $do_cron
1069          * @return void
1070          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1071          */
1072         public static function spawnWorker($do_cron = false)
1073         {
1074                 $command = 'bin/worker.php';
1075
1076                 $args = ['no_cron' => !$do_cron];
1077
1078                 get_app()->proc_run($command, $args);
1079
1080                 // after spawning we have to remove the flag.
1081                 if (Config::get('system', 'worker_daemon_mode', false)) {
1082                         self::IPCSetJobState(false);
1083                 }
1084         }
1085
1086         /**
1087          * @brief Adds tasks to the worker queue
1088          *
1089          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1090          *
1091          * next args are passed as $cmd command line
1092          * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
1093          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1094          *
1095          * @return boolean "false" if proc_run couldn't be executed
1096          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1097          * @note $cmd and string args are surrounded with ""
1098          *
1099          * @hooks 'proc_run'
1100          *    array $arr
1101          *
1102          */
1103         public static function add($cmd)
1104         {
1105                 $args = func_get_args();
1106
1107                 if (!count($args)) {
1108                         return false;
1109                 }
1110
1111                 $arr = ['args' => $args, 'run_cmd' => true];
1112
1113                 Hook::callAll("proc_run", $arr);
1114                 if (!$arr['run_cmd'] || !count($args)) {
1115                         return true;
1116                 }
1117
1118                 $priority = PRIORITY_MEDIUM;
1119                 $dont_fork = Config::get("system", "worker_dont_fork", false);
1120                 $created = DateTimeFormat::utcNow();
1121                 $force_priority = false;
1122
1123                 $run_parameter = array_shift($args);
1124
1125                 if (is_int($run_parameter)) {
1126                         $priority = $run_parameter;
1127                 } elseif (is_array($run_parameter)) {
1128                         if (isset($run_parameter['priority'])) {
1129                                 $priority = $run_parameter['priority'];
1130                         }
1131                         if (isset($run_parameter['created'])) {
1132                                 $created = $run_parameter['created'];
1133                         }
1134                         if (isset($run_parameter['dont_fork'])) {
1135                                 $dont_fork = $run_parameter['dont_fork'];
1136                         }
1137                         if (isset($run_parameter['force_priority'])) {
1138                                 $force_priority = $run_parameter['force_priority'];
1139                         }
1140                 }
1141
1142                 $parameters = json_encode($args);
1143                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1144
1145                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1146                 if (DBA::errorNo() != 0) {
1147                         return false;
1148                 }
1149
1150                 if (!$found) {
1151                         DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1152                 } elseif ($force_priority) {
1153                         DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
1154                 }
1155
1156                 // Should we quit and wait for the worker to be called as a cronjob?
1157                 if ($dont_fork) {
1158                         return true;
1159                 }
1160
1161                 // If there is a lock then we don't have to check for too much worker
1162                 if (!Lock::acquire('worker', 0)) {
1163                         return true;
1164                 }
1165
1166                 // If there are already enough workers running, don't fork another one
1167                 $quit = self::tooMuchWorkers();
1168                 Lock::release('worker');
1169
1170                 if ($quit) {
1171                         return true;
1172                 }
1173
1174                 // We tell the daemon that a new job entry exists
1175                 if (Config::get('system', 'worker_daemon_mode', false)) {
1176                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1177                         return true;
1178                 }
1179
1180                 // Now call the worker to execute the jobs that we just added to the queue
1181                 self::spawnWorker();
1182
1183                 return true;
1184         }
1185
1186         /**
1187          * Defers the current worker entry
1188          */
1189         public static function defer()
1190         {
1191                 if (empty(BaseObject::getApp()->queue)) {
1192                         return;
1193                 }
1194
1195                 $queue = BaseObject::getApp()->queue;
1196
1197                 $retrial = $queue['retrial'];
1198                 $id = $queue['id'];
1199                 $priority = $queue['priority'];
1200
1201                 if ($retrial > 14) {
1202                         Logger::log('Id ' . $id . ' had been tried 14 times. We stop now.', Logger::DEBUG);
1203                         return;
1204                 }
1205
1206                 // Calculate the delay until the next trial
1207                 $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1208                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1209
1210                 if (($priority < PRIORITY_MEDIUM) && ($retrial > 2)) {
1211                         $priority = PRIORITY_MEDIUM;
1212                 } elseif (($priority < PRIORITY_LOW) && ($retrial > 5)) {
1213                         $priority = PRIORITY_LOW;
1214                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($retrial > 7)) {
1215                         $priority = PRIORITY_NEGLIGIBLE;
1216                 }
1217
1218                 Logger::log('Defer execution ' . $retrial . ' of id ' . $id . ' to ' . $next . ' - priority old/new: ' . $queue['priority'] . '/' . $priority, Logger::DEBUG);
1219
1220                 $stamp = (float)microtime(true);
1221                 $fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1222                 DBA::update('workerqueue', $fields, ['id' => $id]);
1223                 self::$db_duration += (microtime(true) - $stamp);
1224                 self::$db_duration_write += (microtime(true) - $stamp);
1225         }
1226
1227         /**
1228          * Log active processes into the "process" table
1229          *
1230          * @brief Log active processes into the "process" table
1231          */
1232         public static function startProcess()
1233         {
1234                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1235
1236                 $command = basename($trace[0]['file']);
1237
1238                 Process::deleteInactive();
1239
1240                 Process::insert($command);
1241         }
1242
1243         /**
1244          * Remove the active process from the "process" table
1245          *
1246          * @brief Remove the active process from the "process" table
1247          * @return bool
1248          * @throws \Exception
1249          */
1250         public static function endProcess()
1251         {
1252                 return Process::deleteByPid();
1253         }
1254
1255         /**
1256          * Set the flag if some job is waiting
1257          *
1258          * @brief Set the flag if some job is waiting
1259          * @param boolean $jobs Is there a waiting job?
1260          * @throws \Exception
1261          */
1262         public static function IPCSetJobState($jobs)
1263         {
1264                 $stamp = (float)microtime(true);
1265                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1266                 self::$db_duration += (microtime(true) - $stamp);
1267                 self::$db_duration_write += (microtime(true) - $stamp);
1268         }
1269
1270         /**
1271          * Checks if some worker job waits to be executed
1272          *
1273          * @brief Checks if some worker job waits to be executed
1274          * @return bool
1275          * @throws \Exception
1276          */
1277         public static function IPCJobsExists()
1278         {
1279                 $stamp = (float)microtime(true);
1280                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1281                 self::$db_duration += (microtime(true) - $stamp);
1282
1283                 // When we don't have a row, no job is running
1284                 if (!DBA::isResult($row)) {
1285                         return false;
1286                 }
1287
1288                 return (bool)$row['jobs'];
1289         }
1290 }