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\Core;
   9 use Friendica\Database\DBA;
  10 use Friendica\Model\Process;
  11 use Friendica\Util\DateTimeFormat;
  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         const FAST_COMMANDS = ['APDelivery', 'Delivery', 'CreateShadowEntry'];
  31
  32
  33         private static $up_start;
  34         private static $db_duration = 0;
  35         private static $db_duration_count = 0;
  36         private static $db_duration_write = 0;
  37         private static $db_duration_stat = 0;
  38         private static $lock_duration = 0;
  39         private static $last_update;
  40         private static $state;
  41
  42         /**
  43          * @brief Processes the tasks that are in the workerqueue table
  44          *
  45          * @param boolean $run_cron Should the cron processes be executed?
  46          * @return void
  47          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  48          */
  49         public static function processQueue($run_cron = true)
  50         {
  51                 $a = \get_app();
  52
  53                 // Ensure that all "strtotime" operations do run timezone independent
  54                 date_default_timezone_set('UTC');
  55
  56                 self::$up_start = microtime(true);
  57
  58                 // At first check the maximum load. We shouldn't continue with a high load
  59                 if ($a->isMaxLoadReached()) {
  60                         Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
  61                         return;
  62                 }
  63
  64                 // We now start the process. This is done after the load check since this could increase the load.
  65                 self::startProcess();
  66
  67                 // Kill stale processes every 5 minutes
  68                 $last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
  69                 if (time() > ($last_cleanup + 300)) {
  70                         Config::set('system', 'worker_last_cleaned', time());
  71                         self::killStaleWorkers();
  72                 }
  73
  74                 // Count active workers and compare them with a maximum value that depends on the load
  75                 if (self::tooMuchWorkers()) {
  76                         Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
  77                         return;
  78                 }
  79
  80                 // Do we have too few memory?
  81                 if ($a->isMinMemoryReached()) {
  82                         Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
  83                         return;
  84                 }
  85
  86                 // Possibly there are too much database connections
  87                 if (self::maxConnectionsReached()) {
  88                         Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
  89                         return;
  90                 }
  91
  92                 // Possibly there are too much database processes that block the system
  93                 if ($a->isMaxProcessesReached()) {
  94                         Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
  95                         return;
  96                 }
  97
  98                 // Now we start additional cron processes if we should do so
  99                 if ($run_cron) {
 100                         self::runCron();
 101                 }
 102
 103                 $starttime = time();
 104                 self::$state = self::STATE_STARTUP;
 105
 106                 // We fetch the next queue entry that is about to be executed
 107                 while ($r = self::workerProcess()) {
 108                         $refetched = false;
 109                         foreach ($r as $entry) {
 110                                 // Assure that the priority is an integer value
 111                                 $entry['priority'] = (int)$entry['priority'];
 112
 113                                 // The work will be done
 114                                 if (!self::execute($entry)) {
 115                                         Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 116                                         return;
 117                                 }
 118
 119                                 // Trying to fetch new processes - but only once when successful
 120                                 if (!$refetched && Lock::acquire('worker_process', 0)) {
 121                                         self::findWorkerProcesses();
 122                                         Lock::release('worker_process');
 123                                         self::$state = self::STATE_REFETCH;
 124                                         $refetched = true;
 125                                 } else {
 126                                         self::$state = self::STATE_SHORT_LOOP;
 127                                 }
 128                         }
 129
 130                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 131                         if (!self::getWaitingJobForPID()) {
 132                                 self::$state = self::STATE_LONG_LOOP;
 133
 134                                 if (Lock::acquire('worker', 0)) {
 135                                 // Count active workers and compare them with a maximum value that depends on the load
 136                                         if (self::tooMuchWorkers()) {
 137                                                 Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 138                                                 Lock::release('worker');
 139                                                 return;
 140                                         }
 141
 142                                         // Check free memory
 143                                         if ($a->isMinMemoryReached()) {
 144                                                 Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 145                                                 Lock::release('worker');
 146                                                 return;
 147                                         }
 148                                         Lock::release('worker');
 149                                 }
 150                         }
 151
 152                         // Quit the worker once every cron interval
 153                         if (time() > ($starttime + (Config::get('system', 'cron_interval') * 60))) {
 154                                 Logger::info('Process lifetime reached, respawning.');
 155                                 self::spawnWorker();
 156                                 return;
 157                         }
 158                 }
 159
 160                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 161                 if (Config::get('system', 'worker_daemon_mode', false)) {
 162                         self::IPCSetJobState(false);
 163                 }
 164                 Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
 165         }
 166
 167         /**
 168          * @brief Check if non executed tasks do exist in the worker queue
 169          *
 170          * @return boolean Returns "true" if tasks are existing
 171          * @throws \Exception
 172          */
 173         private static function entriesExists()
 174         {
 175                 $stamp = (float)microtime(true);
 176                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 177                 self::$db_duration += (microtime(true) - $stamp);
 178                 return $exists;
 179         }
 180
 181         /**
 182          * @brief Returns the number of deferred entries in the worker queue
 183          *
 184          * @return integer Number of deferred entries in the worker queue
 185          * @throws \Exception
 186          */
 187         private static function deferredEntries()
 188         {
 189                 $stamp = (float)microtime(true);
 190                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
 191                 self::$db_duration += (microtime(true) - $stamp);
 192                 self::$db_duration_count += (microtime(true) - $stamp);
 193                 return $count;
 194         }
 195
 196         /**
 197          * @brief Returns the number of non executed entries in the worker queue
 198          *
 199          * @return integer Number of non executed entries in the worker queue
 200          * @throws \Exception
 201          */
 202         private static function totalEntries()
 203         {
 204                 $stamp = (float)microtime(true);
 205                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 206                 self::$db_duration += (microtime(true) - $stamp);
 207                 self::$db_duration_count += (microtime(true) - $stamp);
 208                 return $count;
 209         }
 210
 211         /**
 212          * @brief Returns the highest priority in the worker queue that isn't executed
 213          *
 214          * @return integer Number of active worker processes
 215          * @throws \Exception
 216          */
 217         private static function highestPriority()
 218         {
 219                 $stamp = (float)microtime(true);
 220                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 221                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 222                 self::$db_duration += (microtime(true) - $stamp);
 223                 if (DBA::isResult($workerqueue)) {
 224                         return $workerqueue["priority"];
 225                 } else {
 226                         return 0;
 227                 }
 228         }
 229
 230         /**
 231          * @brief Returns if a process with the given priority is running
 232          *
 233          * @param integer $priority The priority that should be checked
 234          *
 235          * @return integer Is there a process running with that priority?
 236          * @throws \Exception
 237          */
 238         private static function processWithPriorityActive($priority)
 239         {
 240                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 241                 return DBA::exists('workerqueue', $condition);
 242         }
 243
 244         /**
 245          * @brief Execute a worker entry
 246          *
 247          * @param array $queue Workerqueue entry
 248          *
 249          * @return boolean "true" if further processing should be stopped
 250          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 251          */
 252         public static function execute($queue)
 253         {
 254                 $a = \get_app();
 255
 256                 $mypid = getmypid();
 257
 258                 // Quit when in maintenance
 259                 if (Config::get('system', 'maintenance', false, true)) {
 260                         Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 261                         return false;
 262                 }
 263
 264                 // Constantly check the number of parallel database processes
 265                 if ($a->isMaxProcessesReached()) {
 266                         Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 267                         return false;
 268                 }
 269
 270                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 271                 if (self::maxConnectionsReached()) {
 272                         Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 273                         return false;
 274                 }
 275
 276                 $argv = json_decode($queue["parameter"], true);
 277
 278                 // Check for existance and validity of the include file
 279                 $include = $argv[0];
 280
 281                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 282                         // We constantly update the "executed" date every minute to avoid being killed too soon
 283                         if (!isset(self::$last_update)) {
 284                                 self::$last_update = strtotime($queue["executed"]);
 285                         }
 286
 287                         $age = (time() - self::$last_update) / 60;
 288                         self::$last_update = time();
 289
 290                         if ($age > 1) {
 291                                 $stamp = (float)microtime(true);
 292                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 293                                 self::$db_duration += (microtime(true) - $stamp);
 294                                 self::$db_duration_write += (microtime(true) - $stamp);
 295                         }
 296
 297                         array_shift($argv);
 298
 299                         self::execFunction($queue, $include, $argv, true);
 300
 301                         $stamp = (float)microtime(true);
 302                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 303                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 304                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 305                         }
 306                         self::$db_duration = (microtime(true) - $stamp);
 307                         self::$db_duration_write += (microtime(true) - $stamp);
 308
 309                         return true;
 310                 }
 311
 312                 // The script could be provided as full path or only with the function name
 313                 if ($include == basename($include)) {
 314                         $include = "include/".$include.".php";
 315                 }
 316
 317                 if (!validate_include($include)) {
 318                         Logger::log("Include file ".$argv[0]." is not valid!");
 319                         $stamp = (float)microtime(true);
 320                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 321                         self::$db_duration = (microtime(true) - $stamp);
 322                         self::$db_duration_write += (microtime(true) - $stamp);
 323                         return true;
 324                 }
 325
 326                 require_once $include;
 327
 328                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 329
 330                 if (function_exists($funcname)) {
 331                         // We constantly update the "executed" date every minute to avoid being killed too soon
 332                         if (!isset(self::$last_update)) {
 333                                 self::$last_update = strtotime($queue["executed"]);
 334                         }
 335
 336                         $age = (time() - self::$last_update) / 60;
 337                         self::$last_update = time();
 338
 339                         if ($age > 1) {
 340                                 $stamp = (float)microtime(true);
 341                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 342                                 self::$db_duration += (microtime(true) - $stamp);
 343                                 self::$db_duration_write += (microtime(true) - $stamp);
 344                         }
 345
 346                         self::execFunction($queue, $funcname, $argv, false);
 347
 348                         $stamp = (float)microtime(true);
 349                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 350                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 351                         }
 352                         self::$db_duration = (microtime(true) - $stamp);
 353                         self::$db_duration_write += (microtime(true) - $stamp);
 354                 } else {
 355                         Logger::log("Function ".$funcname." does not exist");
 356                         $stamp = (float)microtime(true);
 357                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 358                         self::$db_duration = (microtime(true) - $stamp);
 359                         self::$db_duration_write += (microtime(true) - $stamp);
 360                 }
 361
 362                 return true;
 363         }
 364
 365         /**
 366          * @brief Execute a function from the queue
 367          *
 368          * @param array   $queue       Workerqueue entry
 369          * @param string  $funcname    name of the function
 370          * @param array   $argv        Array of values to be passed to the function
 371          * @param boolean $method_call boolean
 372          * @return void
 373          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 374          */
 375         private static function execFunction($queue, $funcname, $argv, $method_call)
 376         {
 377                 $a = \get_app();
 378
 379                 $argc = count($argv);
 380
 381                 Logger::enableWorker($funcname);
 382
 383                 Logger::info("Process start.", ['priority' => $queue["priority"], 'id' => $queue["id"]]);
 384
 385                 $stamp = (float)microtime(true);
 386
 387                 // We use the callstack here to analyze the performance of executed worker entries.
 388                 // For this reason the variables have to be initialized.
 389                 $a->getProfiler()->reset();
 390
 391                 $a->queue = $queue;
 392
 393                 $up_duration = microtime(true) - self::$up_start;
 394
 395                 // Reset global data to avoid interferences
 396                 unset($_SESSION);
 397
 398                 // Set the workerLogger as new default logger
 399                 if ($method_call) {
 400                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 401                 } else {
 402                         $funcname($argv, $argc);
 403                 }
 404
 405                 Logger::disableWorker();
 406
 407                 unset($a->queue);
 408
 409                 $duration = (microtime(true) - $stamp);
 410
 411                 /* With these values we can analyze how effective the worker is.
 412                  * The database and rest time should be low since this is the unproductive time.
 413                  * The execution time is the productive time.
 414                  * By changing parameters like the maximum number of workers we can check the effectivness.
 415                 */
 416                 $dbtotal = round(self::$db_duration, 2);
 417                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 418                 $dbcount = round(self::$db_duration_count, 2);
 419                 $dbstat  = round(self::$db_duration_stat, 2);
 420                 $dbwrite = round(self::$db_duration_write, 2);
 421                 $dblock  = round(self::$lock_duration, 2);
 422                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 423                 $exec    = round($duration, 2);
 424
 425                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 426
 427                 self::$up_start = microtime(true);
 428                 self::$db_duration = 0;
 429                 self::$db_duration_count = 0;
 430                 self::$db_duration_stat = 0;
 431                 self::$db_duration_write = 0;
 432                 self::$lock_duration = 0;
 433
 434                 if ($duration > 3600) {
 435                         Logger::info('Longer than 1 hour.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 436                 } elseif ($duration > 600) {
 437                         Logger::info('Longer than 10 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 438                 } elseif ($duration > 300) {
 439                         Logger::info('Longer than 5 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 440                 } elseif ($duration > 120) {
 441                         Logger::info('Longer than 2 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 442                 }
 443
 444                 Logger::info('Process done.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration, 3)]);
 445
 446                 $a->getProfiler()->saveLog($a->getLogger(), "ID " . $queue["id"] . ": " . $funcname);
 447
 448                 $cooldown = Config::get("system", "worker_cooldown", 0);
 449
 450                 if ($cooldown > 0) {
 451                         Logger::info('Cooldown.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'cooldown' => $cooldown]);
 452                         sleep($cooldown);
 453                 }
 454         }
 455
 456         /**
 457          * @brief Checks if the number of database connections has reached a critical limit.
 458          *
 459          * @return bool Are more than 3/4 of the maximum connections used?
 460          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 461          */
 462         private static function maxConnectionsReached()
 463         {
 464                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 465                 $max = Config::get("system", "max_connections");
 466
 467                 // Fetch the percentage level where the worker will get active
 468                 $maxlevel = Config::get("system", "max_connections_level", 75);
 469
 470                 if ($max == 0) {
 471                         // the maximum number of possible user connections can be a system variable
 472                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 473                         if (DBA::isResult($r)) {
 474                                 $max = $r["Value"];
 475                         }
 476                         // Or it can be granted. This overrides the system variable
 477                         $stamp = (float)microtime(true);
 478                         $r = DBA::p('SHOW GRANTS');
 479                         self::$db_duration += (microtime(true) - $stamp);
 480                         while ($grants = DBA::fetch($r)) {
 481                                 $grant = array_pop($grants);
 482                                 if (stristr($grant, "GRANT USAGE ON")) {
 483                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 484                                                 $max = $match[1];
 485                                         }
 486                                 }
 487                         }
 488                         DBA::close($r);
 489                 }
 490
 491                 // If $max is set we will use the processlist to determine the current number of connections
 492                 // The processlist only shows entries of the current user
 493                 if ($max != 0) {
 494                         $stamp = (float)microtime(true);
 495                         $r = DBA::p('SHOW PROCESSLIST');
 496                         self::$db_duration += (microtime(true) - $stamp);
 497                         $used = DBA::numRows($r);
 498                         DBA::close($r);
 499
 500                         Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 501
 502                         $level = ($used / $max) * 100;
 503
 504                         if ($level >= $maxlevel) {
 505                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 506                                 return true;
 507                         }
 508                 }
 509
 510                 // We will now check for the system values.
 511                 // This limit could be reached although the user limits are fine.
 512                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 513                 if (!DBA::isResult($r)) {
 514                         return false;
 515                 }
 516                 $max = intval($r["Value"]);
 517                 if ($max == 0) {
 518                         return false;
 519                 }
 520                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 521                 if (!DBA::isResult($r)) {
 522                         return false;
 523                 }
 524                 $used = intval($r["Value"]);
 525                 if ($used == 0) {
 526                         return false;
 527                 }
 528                 Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 529
 530                 $level = $used / $max * 100;
 531
 532                 if ($level < $maxlevel) {
 533                         return false;
 534                 }
 535                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 536                 return true;
 537         }
 538
 539         /**
 540          * @brief fix the queue entry if the worker process died
 541          * @return void
 542          * @throws \Exception
 543          */
 544         private static function killStaleWorkers()
 545         {
 546                 $stamp = (float)microtime(true);
 547                 $entries = DBA::select(
 548                         'workerqueue',
 549                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 550                         ['NOT `done` AND `pid` != 0'],
 551                         ['order' => ['priority', 'created']]
 552                 );
 553                 self::$db_duration += (microtime(true) - $stamp);
 554
 555                 while ($entry = DBA::fetch($entries)) {
 556                         if (!posix_kill($entry["pid"], 0)) {
 557                                 $stamp = (float)microtime(true);
 558                                 DBA::update(
 559                                         'workerqueue',
 560                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 561                                         ['id' => $entry["id"]]
 562                                 );
 563                                 self::$db_duration += (microtime(true) - $stamp);
 564                                 self::$db_duration_write += (microtime(true) - $stamp);
 565                         } else {
 566                                 // Kill long running processes
 567                                 // Check if the priority is in a valid range
 568                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 569                                         $entry["priority"] = PRIORITY_MEDIUM;
 570                                 }
 571
 572                                 // Define the maximum durations
 573                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 574                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 575
 576                                 $argv = json_decode($entry["parameter"], true);
 577                                 $argv[0] = basename($argv[0]);
 578
 579                                 // How long is the process already running?
 580                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 581                                 if ($duration > $max_duration) {
 582                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 583                                         posix_kill($entry["pid"], SIGTERM);
 584
 585                                         // We killed the stale process.
 586                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 587                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 588                                         $new_priority = $entry["priority"];
 589                                         if ($entry["priority"] == PRIORITY_HIGH) {
 590                                                 $new_priority = PRIORITY_MEDIUM;
 591                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 592                                                 $new_priority = PRIORITY_LOW;
 593                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 594                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 595                                         }
 596                                         $stamp = (float)microtime(true);
 597                                         DBA::update(
 598                                                 'workerqueue',
 599                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 600                                                 ['id' => $entry["id"]]
 601                                         );
 602                                         self::$db_duration += (microtime(true) - $stamp);
 603                                         self::$db_duration_write += (microtime(true) - $stamp);
 604                                 } else {
 605                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 606                                 }
 607                         }
 608                 }
 609         }
 610
 611         /**
 612          * @brief Checks if the number of active workers exceeds the given limits
 613          *
 614          * @return bool Are there too much workers running?
 615          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 616          */
 617         private static function tooMuchWorkers()
 618         {
 619                 $queues = Config::get("system", "worker_queues", 10);
 620
 621                 $maxqueues = $queues;
 622
 623                 $active = self::activeWorkers();
 624
 625                 // Decrease the number of workers at higher load
 626                 $load = System::currentLoad();
 627                 if ($load) {
 628                         $maxsysload = intval(Config::get("system", "maxloadavg", 20));
 629
 630                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 631                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 632                          * For some environments, this rapid decrease is not needed.
 633                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 634                          */
 635                         $exponent = intval(Config::get('system', 'worker_load_exponent', 3));
 636                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 637                         $queues = intval(ceil($slope * $maxqueues));
 638
 639                         $processlist = '';
 640
 641                         if (Config::get('system', 'worker_jpm')) {
 642                                 $intervals = explode(',', Config::get('system', 'worker_jpm_range'));
 643                                 $jobs_per_minute = [];
 644                                 foreach ($intervals as $interval) {
 645                                         if ($interval == 0) {
 646                                                 continue;
 647                                         } else {
 648                                                 $interval = (int)$interval;
 649                                         }
 650
 651                                         $stamp = (float)microtime(true);
 652                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
 653                                         self::$db_duration += (microtime(true) - $stamp);
 654                                         self::$db_duration_stat += (microtime(true) - $stamp);
 655                                         if ($job = DBA::fetch($jobs)) {
 656                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 657                                         }
 658                                         DBA::close($jobs);
 659                                 }
 660                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 661                         }
 662
 663                         // Create a list of queue entries grouped by their priority
 664                         $listitem = [0 => ''];
 665
 666                         $idle_workers = $active;
 667
 668                         $deferred = self::deferredEntries();
 669
 670                         if (Config::get('system', 'worker_debug')) {
 671                                 $waiting_processes = 0;
 672                                 // Now adding all processes with workerqueue entries
 673                                 $stamp = (float)microtime(true);
 674                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 675                                 self::$db_duration += (microtime(true) - $stamp);
 676                                 self::$db_duration_stat += (microtime(true) - $stamp);
 677                                 while ($entry = DBA::fetch($jobs)) {
 678                                         $stamp = (float)microtime(true);
 679                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `priority` = ?", $entry["priority"]);
 680                                         self::$db_duration += (microtime(true) - $stamp);
 681                                         self::$db_duration_stat += (microtime(true) - $stamp);
 682                                         if ($process = DBA::fetch($processes)) {
 683                                                 $idle_workers -= $process["running"];
 684                                                 $waiting_processes += $entry["entries"];
 685                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 686                                         }
 687                                         DBA::close($processes);
 688                                 }
 689                                 DBA::close($jobs);
 690                         } else {
 691                                 $waiting_processes =  self::totalEntries();
 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                         $waiting_processes -= $deferred;
 705
 706                         $listitem[0] = "0:" . max(0, $idle_workers);
 707
 708                         $processlist .= ' ('.implode(', ', $listitem).')';
 709
 710                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 711                                 $top_priority = self::highestPriority();
 712                                 $high_running = self::processWithPriorityActive($top_priority);
 713
 714                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 715                                         Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 716                                         $queues = $active + 1;
 717                                 }
 718                         }
 719
 720                         Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 721
 722                         // Are there fewer workers running as possible? Then fork a new one.
 723                         if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && self::entriesExists()) {
 724                                 Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 725                                 if (Config::get('system', 'worker_daemon_mode', false)) {
 726                                         self::IPCSetJobState(true);
 727                                 } else {
 728                                         self::spawnWorker();
 729                                 }
 730                         }
 731                 }
 732
 733                 // if there are too much worker, we don't spawn a new one.
 734                 if (Config::get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 735                         self::IPCSetJobState(false);
 736                 }
 737
 738                 return $active > $queues;
 739         }
 740
 741         /**
 742          * @brief Returns the number of active worker processes
 743          *
 744          * @return integer Number of active worker processes
 745          * @throws \Exception
 746          */
 747         private static function activeWorkers()
 748         {
 749                 $stamp = (float)microtime(true);
 750                 $count = DBA::count('process', ['command' => 'Worker.php']);
 751                 self::$db_duration += (microtime(true) - $stamp);
 752                 return $count;
 753         }
 754
 755         /**
 756          * @brief Returns waiting jobs for the current process id
 757          *
 758          * @return array waiting workerqueue jobs
 759          * @throws \Exception
 760          */
 761         private static function getWaitingJobForPID()
 762         {
 763                 $stamp = (float)microtime(true);
 764                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 765                 self::$db_duration += (microtime(true) - $stamp);
 766                 if (DBA::isResult($r)) {
 767                         return DBA::toArray($r);
 768                 }
 769                 DBA::close($r);
 770
 771                 return false;
 772         }
 773
 774         /**
 775          * @brief Returns the next jobs that should be executed
 776          *
 777          * @return array array with next jobs
 778          * @throws \Exception
 779          */
 780         private static function nextProcess()
 781         {
 782                 $priority = self::nextPriority();
 783                 if (empty($priority)) {
 784                         Logger::info('No tasks found');
 785                         return [];
 786                 }
 787
 788                 $limit = Config::get('system', 'worker_fetch_limit', 1);
 789
 790                 $ids = [];
 791                 $stamp = (float)microtime(true);
 792                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 793                 $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['created']]);
 794                 self::$db_duration += (microtime(true) - $stamp);
 795                 while ($task = DBA::fetch($tasks)) {
 796                         $ids[] = $task['id'];
 797                         // Only continue that loop while we are storing commands that can be processed quickly
 798                         $command = json_decode($task['parameter'])[0];
 799                         if (!in_array($command, self::FAST_COMMANDS)) {
 800                                 break;
 801                         }
 802                 }
 803                 DBA::close($tasks);
 804
 805                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
 806                 return $ids;
 807         }
 808
 809         /**
 810          * @brief Returns the priority of the next workerqueue job
 811          *
 812          * @return string priority
 813          * @throws \Exception
 814          */
 815         private static function nextPriority()
 816         {
 817                 $waiting = [];
 818                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
 819                 foreach ($priorities as $priority) {
 820                         $stamp = (float)microtime(true);
 821                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 822                                 $waiting[$priority] = true;
 823                         }
 824                         self::$db_duration += (microtime(true) - $stamp);
 825                 }
 826
 827                 if (!empty($waiting[PRIORITY_CRITICAL])) {
 828                         return PRIORITY_CRITICAL;
 829                 }
 830
 831                 $running = [];
 832                 $running_total = 0;
 833                 $stamp = (float)microtime(true);
 834                 $processes = DBA::p("SELECT COUNT(DISTINCT(`process`.`pid`)) AS `running`, `priority` FROM `process`
 835                         INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
 836                         WHERE NOT `done` GROUP BY `priority`");
 837                 self::$db_duration += (microtime(true) - $stamp);
 838                 while ($process = DBA::fetch($processes)) {
 839                         $running[$process['priority']] = $process['running'];
 840                         $running_total += $process['running'];
 841                 }
 842                 DBA::close($processes);
 843
 844                 foreach ($priorities as $priority) {
 845                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 846                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 847                                 return $priority;
 848                         }
 849                 }
 850
 851                 $active = max(self::activeWorkers(), $running_total);
 852                 $priorities = max(count($waiting), count($running));
 853                 $exponent = 2;
 854
 855                 $total = 0;
 856                 for ($i = 1; $i <= $priorities; ++$i) {
 857                         $total += pow($i, $exponent);
 858                 }
 859
 860                 $limit = [];
 861                 for ($i = 1; $i <= $priorities; ++$i) {
 862                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 863                 }
 864
 865                 $i = 0;
 866                 foreach ($running as $priority => $workers) {
 867                         if ($workers < $limit[$i++]) {
 868                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 869                                 return $priority;
 870                         }
 871                 }
 872
 873                 if (!empty($waiting)) {
 874                         $priority = array_keys($waiting)[0];
 875                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
 876                         return $priority;
 877                 }
 878
 879                 return false;
 880         }
 881
 882         /**
 883          * @brief Find and claim the next worker process for us
 884          *
 885          * @return boolean Have we found something?
 886          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 887          */
 888         private static function findWorkerProcesses()
 889         {
 890                 $mypid = getmypid();
 891
 892                 $ids = self::nextProcess();
 893
 894                 // If there is no result we check without priority limit
 895                 if (empty($ids)) {
 896                         $limit = Config::get('system', 'worker_fetch_limit', 1);
 897
 898                         $stamp = (float)microtime(true);
 899                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 900                         $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'created']]);
 901                         self::$db_duration += (microtime(true) - $stamp);
 902
 903                         while ($task = DBA::fetch($tasks)) {
 904                                 $ids[] = $task['id'];
 905                                 // Only continue that loop while we are storing commands that can be processed quickly
 906                                 $command = json_decode($task['parameter'])[0];
 907                                 if (!in_array($command, self::FAST_COMMANDS)) {
 908                                         break;
 909                                 }
 910                         }
 911                         DBA::close($tasks);
 912                 }
 913
 914                 if (!empty($ids)) {
 915                         $stamp = (float)microtime(true);
 916                         $condition = ['id' => $ids, 'done' => false, 'pid' => 0];
 917                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $condition);
 918                         self::$db_duration += (microtime(true) - $stamp);
 919                         self::$db_duration_write += (microtime(true) - $stamp);
 920                 }
 921
 922                 return !empty($ids);
 923         }
 924
 925         /**
 926          * @brief Returns the next worker process
 927          *
 928          * @return string SQL statement
 929          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 930          */
 931         public static function workerProcess()
 932         {
 933                 // There can already be jobs for us in the queue.
 934                 $waiting = self::getWaitingJobForPID();
 935                 if (!empty($waiting)) {
 936                         return $waiting;
 937                 }
 938
 939                 $stamp = (float)microtime(true);
 940                 if (!Lock::acquire('worker_process')) {
 941                         return false;
 942                 }
 943                 self::$lock_duration += (microtime(true) - $stamp);
 944
 945                 $found = self::findWorkerProcesses();
 946
 947                 Lock::release('worker_process');
 948
 949                 if ($found) {
 950                         $stamp = (float)microtime(true);
 951                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 952                         self::$db_duration += (microtime(true) - $stamp);
 953                         return DBA::toArray($r);
 954                 }
 955                 return false;
 956         }
 957
 958         /**
 959          * @brief Removes a workerqueue entry from the current process
 960          * @return void
 961          * @throws \Exception
 962          */
 963         public static function unclaimProcess()
 964         {
 965                 $mypid = getmypid();
 966
 967                 $stamp = (float)microtime(true);
 968                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 969                 self::$db_duration += (microtime(true) - $stamp);
 970                 self::$db_duration_write += (microtime(true) - $stamp);
 971         }
 972
 973         /**
 974          * @brief Call the front end worker
 975          * @return void
 976          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 977          */
 978         public static function callWorker()
 979         {
 980                 if (!Config::get("system", "frontend_worker")) {
 981                         return;
 982                 }
 983
 984                 $url = System::baseUrl()."/worker";
 985                 Network::fetchUrl($url, false, 1);
 986         }
 987
 988         /**
 989          * @brief Call the front end worker if there aren't any active
 990          * @return void
 991          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 992          */
 993         public static function executeIfIdle()
 994         {
 995                 if (!Config::get("system", "frontend_worker")) {
 996                         return;
 997                 }
 998
 999                 // Do we have "proc_open"? Then we can fork the worker
1000                 if (function_exists("proc_open")) {
1001                         // When was the last time that we called the worker?
1002                         // Less than one minute? Then we quit
1003                         if ((time() - Config::get("system", "worker_started")) < 60) {
1004                                 return;
1005                         }
1006
1007                         Config::set("system", "worker_started", time());
1008
1009                         // Do we have enough running workers? Then we quit here.
1010                         if (self::tooMuchWorkers()) {
1011                                 // Cleaning dead processes
1012                                 self::killStaleWorkers();
1013                                 Process::deleteInactive();
1014
1015                                 return;
1016                         }
1017
1018                         self::runCron();
1019
1020                         Logger::log('Call worker', Logger::DEBUG);
1021                         self::spawnWorker();
1022                         return;
1023                 }
1024
1025                 // We cannot execute background processes.
1026                 // We now run the processes from the frontend.
1027                 // This won't work with long running processes.
1028                 self::runCron();
1029
1030                 self::clearProcesses();
1031
1032                 $workers = self::activeWorkers();
1033
1034                 if ($workers == 0) {
1035                         self::callWorker();
1036                 }
1037         }
1038
1039         /**
1040          * @brief Removes long running worker processes
1041          * @return void
1042          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1043          */
1044         public static function clearProcesses()
1045         {
1046                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
1047
1048                 /// @todo We should clean up the corresponding workerqueue entries as well
1049                 $stamp = (float)microtime(true);
1050                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1051                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1052                 DBA::delete('process', $condition);
1053                 self::$db_duration = (microtime(true) - $stamp);
1054                 self::$db_duration_write += (microtime(true) - $stamp);
1055         }
1056
1057         /**
1058          * @brief Runs the cron processes
1059          * @return void
1060          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1061          */
1062         private static function runCron()
1063         {
1064                 Logger::log('Add cron entries', Logger::DEBUG);
1065
1066                 // Check for spooled items
1067                 self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
1068
1069                 // Run the cron job that calls all other jobs
1070                 self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
1071
1072                 // Cleaning dead processes
1073                 self::killStaleWorkers();
1074         }
1075
1076         /**
1077          * @brief Spawns a new worker
1078          * @param bool $do_cron
1079          * @return void
1080          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1081          */
1082         public static function spawnWorker($do_cron = false)
1083         {
1084                 $command = 'bin/worker.php';
1085
1086                 $args = ['no_cron' => !$do_cron];
1087
1088                 $a = get_app();
1089                 $process = new Core\Process($a->getLogger(), $a->getMode(), $a->getConfig(), $a->getBasePath());
1090                 $process->run($command, $args);
1091
1092                 // after spawning we have to remove the flag.
1093                 if (Config::get('system', 'worker_daemon_mode', false)) {
1094                         self::IPCSetJobState(false);
1095                 }
1096         }
1097
1098         /**
1099          * @brief Adds tasks to the worker queue
1100          *
1101          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1102          *
1103          * next args are passed as $cmd command line
1104          * or: Worker::add(PRIORITY_HIGH, "Notifier", Delivery::DELETION, $drop_id);
1105          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1106          *
1107          * @return boolean "false" if worker queue entry already existed or there had been an error
1108          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1109          * @note $cmd and string args are surrounded with ""
1110          *
1111          * @hooks 'proc_run'
1112          *    array $arr
1113          *
1114          */
1115         public static function add($cmd)
1116         {
1117                 $args = func_get_args();
1118
1119                 if (!count($args)) {
1120                         return false;
1121                 }
1122
1123                 $arr = ['args' => $args, 'run_cmd' => true];
1124
1125                 Hook::callAll("proc_run", $arr);
1126                 if (!$arr['run_cmd'] || !count($args)) {
1127                         return true;
1128                 }
1129
1130                 $priority = PRIORITY_MEDIUM;
1131                 // Don't fork from frontend tasks by default
1132                 $dont_fork = Config::get("system", "worker_dont_fork", false) || !\get_app()->getMode()->isBackend();
1133                 $created = DateTimeFormat::utcNow();
1134                 $force_priority = false;
1135
1136                 $run_parameter = array_shift($args);
1137
1138                 if (is_int($run_parameter)) {
1139                         $priority = $run_parameter;
1140                 } elseif (is_array($run_parameter)) {
1141                         if (isset($run_parameter['priority'])) {
1142                                 $priority = $run_parameter['priority'];
1143                         }
1144                         if (isset($run_parameter['created'])) {
1145                                 $created = $run_parameter['created'];
1146                         }
1147                         if (isset($run_parameter['dont_fork'])) {
1148                                 $dont_fork = $run_parameter['dont_fork'];
1149                         }
1150                         if (isset($run_parameter['force_priority'])) {
1151                                 $force_priority = $run_parameter['force_priority'];
1152                         }
1153                 }
1154
1155                 $parameters = json_encode($args);
1156                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1157                 $added = false;
1158
1159                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1160                 if (DBA::errorNo() != 0) {
1161                         return false;
1162                 }
1163
1164                 if (!$found) {
1165                         $added = DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1166                         if (!$added) {
1167                                 return false;
1168                         }
1169                 } elseif ($force_priority) {
1170                         DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
1171                 }
1172
1173                 // Should we quit and wait for the worker to be called as a cronjob?
1174                 if ($dont_fork) {
1175                         return $added;
1176                 }
1177
1178                 // If there is a lock then we don't have to check for too much worker
1179                 if (!Lock::acquire('worker', 0)) {
1180                         return $added;
1181                 }
1182
1183                 // If there are already enough workers running, don't fork another one
1184                 $quit = self::tooMuchWorkers();
1185                 Lock::release('worker');
1186
1187                 if ($quit) {
1188                         return $added;
1189                 }
1190
1191                 // We tell the daemon that a new job entry exists
1192                 if (Config::get('system', 'worker_daemon_mode', false)) {
1193                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1194                         return $added;
1195                 }
1196
1197                 // Now call the worker to execute the jobs that we just added to the queue
1198                 self::spawnWorker();
1199
1200                 return $added;
1201         }
1202
1203         /**
1204          * Returns the next retrial level for worker jobs.
1205          * This function will skip levels when jobs are older.
1206          *
1207          * @param array $queue Worker queue entry
1208          * @param integer $max_level maximum retrial level
1209          * @return integer the next retrial level value
1210          */
1211         private static function getNextRetrial($queue, $max_level)
1212         {
1213                 $created = strtotime($queue['created']);
1214                 $retrial_time = time() - $created;
1215
1216                 $new_retrial = $queue['retrial'] + 1;
1217                 $total = 0;
1218                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1219                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1220                         $total += $delay;
1221                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1222                                 $new_retrial = $retrial;
1223                         }
1224                 }
1225                 Logger::info('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1226                 return $new_retrial;
1227         }
1228
1229         /**
1230          * Defers the current worker entry
1231          * @return boolean had the entry been deferred?
1232          */
1233         public static function defer()
1234         {
1235                 if (empty(BaseObject::getApp()->queue)) {
1236                         return false;
1237                 }
1238
1239                 $queue = BaseObject::getApp()->queue;
1240
1241                 $retrial = $queue['retrial'];
1242                 $id = $queue['id'];
1243                 $priority = $queue['priority'];
1244
1245                 $max_level = Config::get('system', 'worker_defer_limit');
1246
1247                 $new_retrial = self::getNextRetrial($queue, $max_level);
1248
1249                 if ($new_retrial > $max_level) {
1250                         Logger::info('The task exceeded the maximum retry count', ['id' => $id, 'created' => $queue['created'], 'old_prio' => $queue['priority'], 'old_retrial' => $queue['retrial'], 'max_level' => $max_level, 'retrial' => $new_retrial]);
1251                         return false;
1252                 }
1253
1254                 // Calculate the delay until the next trial
1255                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1256                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1257
1258                 if (($priority < PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1259                         $priority = PRIORITY_MEDIUM;
1260                 } elseif (($priority < PRIORITY_LOW) && ($new_retrial > 6)) {
1261                         $priority = PRIORITY_LOW;
1262                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1263                         $priority = PRIORITY_NEGLIGIBLE;
1264                 }
1265
1266                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1267
1268                 $stamp = (float)microtime(true);
1269                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1270                 DBA::update('workerqueue', $fields, ['id' => $id]);
1271                 self::$db_duration += (microtime(true) - $stamp);
1272                 self::$db_duration_write += (microtime(true) - $stamp);
1273
1274                 return true;
1275         }
1276
1277         /**
1278          * Log active processes into the "process" table
1279          *
1280          * @brief Log active processes into the "process" table
1281          */
1282         public static function startProcess()
1283         {
1284                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1285
1286                 $command = basename($trace[0]['file']);
1287
1288                 Process::deleteInactive();
1289
1290                 Process::insert($command);
1291         }
1292
1293         /**
1294          * Remove the active process from the "process" table
1295          *
1296          * @brief Remove the active process from the "process" table
1297          * @return bool
1298          * @throws \Exception
1299          */
1300         public static function endProcess()
1301         {
1302                 return Process::deleteByPid();
1303         }
1304
1305         /**
1306          * Set the flag if some job is waiting
1307          *
1308          * @brief Set the flag if some job is waiting
1309          * @param boolean $jobs Is there a waiting job?
1310          * @throws \Exception
1311          */
1312         public static function IPCSetJobState($jobs)
1313         {
1314                 $stamp = (float)microtime(true);
1315                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1316                 self::$db_duration += (microtime(true) - $stamp);
1317                 self::$db_duration_write += (microtime(true) - $stamp);
1318         }
1319
1320         /**
1321          * Checks if some worker job waits to be executed
1322          *
1323          * @brief Checks if some worker job waits to be executed
1324          * @return bool
1325          * @throws \Exception
1326          */
1327         public static function IPCJobsExists()
1328         {
1329                 $stamp = (float)microtime(true);
1330                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1331                 self::$db_duration += (microtime(true) - $stamp);
1332
1333                 // When we don't have a row, no job is running
1334                 if (!DBA::isResult($row)) {
1335                         return false;
1336                 }
1337
1338                 return (bool)$row['jobs'];
1339         }
1340 }