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\DI;
  11 use Friendica\Model\Process;
  12 use Friendica\Util\DateTimeFormat;
  13 use Friendica\Util\Network;
  14
  15 /**
  16  * @file src/Core/Worker.php
  17  *
  18  * @brief Contains the class for the worker background job processing
  19  */
  20
  21 /**
  22  * @brief Worker methods
  23  */
  24 class Worker
  25 {
  26         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
  27         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
  28         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
  29         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
  30
  31         const FAST_COMMANDS = ['APDelivery', 'Delivery', 'CreateShadowEntry'];
  32
  33
  34         private static $up_start;
  35         private static $db_duration = 0;
  36         private static $db_duration_count = 0;
  37         private static $db_duration_write = 0;
  38         private static $db_duration_stat = 0;
  39         private static $lock_duration = 0;
  40         private static $last_update;
  41         private static $state;
  42
  43         /**
  44          * @brief Processes the tasks that are in the workerqueue table
  45          *
  46          * @param boolean $run_cron Should the cron processes be executed?
  47          * @return void
  48          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  49          */
  50         public static function processQueue($run_cron = true)
  51         {
  52                 $a = \get_app();
  53
  54                 // Ensure that all "strtotime" operations do run timezone independent
  55                 date_default_timezone_set('UTC');
  56
  57                 self::$up_start = microtime(true);
  58
  59                 // At first check the maximum load. We shouldn't continue with a high load
  60                 if ($a->isMaxLoadReached()) {
  61                         Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
  62                         return;
  63                 }
  64
  65                 // We now start the process. This is done after the load check since this could increase the load.
  66                 self::startProcess();
  67
  68                 // Kill stale processes every 5 minutes
  69                 $last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
  70                 if (time() > ($last_cleanup + 300)) {
  71                         Config::set('system', 'worker_last_cleaned', time());
  72                         self::killStaleWorkers();
  73                 }
  74
  75                 // Count active workers and compare them with a maximum value that depends on the load
  76                 if (self::tooMuchWorkers()) {
  77                         Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
  78                         return;
  79                 }
  80
  81                 // Do we have too few memory?
  82                 if ($a->isMinMemoryReached()) {
  83                         Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
  84                         return;
  85                 }
  86
  87                 // Possibly there are too much database connections
  88                 if (self::maxConnectionsReached()) {
  89                         Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
  90                         return;
  91                 }
  92
  93                 // Possibly there are too much database processes that block the system
  94                 if ($a->isMaxProcessesReached()) {
  95                         Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
  96                         return;
  97                 }
  98
  99                 // Now we start additional cron processes if we should do so
 100                 if ($run_cron) {
 101                         self::runCron();
 102                 }
 103
 104                 $starttime = time();
 105                 self::$state = self::STATE_STARTUP;
 106
 107                 // We fetch the next queue entry that is about to be executed
 108                 while ($r = self::workerProcess()) {
 109                         $refetched = false;
 110                         foreach ($r as $entry) {
 111                                 // Assure that the priority is an integer value
 112                                 $entry['priority'] = (int)$entry['priority'];
 113
 114                                 // The work will be done
 115                                 if (!self::execute($entry)) {
 116                                         Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 117                                         return;
 118                                 }
 119
 120                                 // Trying to fetch new processes - but only once when successful
 121                                 if (!$refetched && Lock::acquire('worker_process', 0)) {
 122                                         self::findWorkerProcesses();
 123                                         Lock::release('worker_process');
 124                                         self::$state = self::STATE_REFETCH;
 125                                         $refetched = true;
 126                                 } else {
 127                                         self::$state = self::STATE_SHORT_LOOP;
 128                                 }
 129                         }
 130
 131                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 132                         if (!self::getWaitingJobForPID()) {
 133                                 self::$state = self::STATE_LONG_LOOP;
 134
 135                                 if (Lock::acquire('worker', 0)) {
 136                                 // Count active workers and compare them with a maximum value that depends on the load
 137                                         if (self::tooMuchWorkers()) {
 138                                                 Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 139                                                 Lock::release('worker');
 140                                                 return;
 141                                         }
 142
 143                                         // Check free memory
 144                                         if ($a->isMinMemoryReached()) {
 145                                                 Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 146                                                 Lock::release('worker');
 147                                                 return;
 148                                         }
 149                                         Lock::release('worker');
 150                                 }
 151                         }
 152
 153                         // Quit the worker once every cron interval
 154                         if (time() > ($starttime + (Config::get('system', 'cron_interval') * 60))) {
 155                                 Logger::info('Process lifetime reached, respawning.');
 156                                 self::spawnWorker();
 157                                 return;
 158                         }
 159                 }
 160
 161                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 162                 if (Config::get('system', 'worker_daemon_mode', false)) {
 163                         self::IPCSetJobState(false);
 164                 }
 165                 Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
 166         }
 167
 168         /**
 169          * @brief Check if non executed tasks do exist in the worker queue
 170          *
 171          * @return boolean Returns "true" if tasks are existing
 172          * @throws \Exception
 173          */
 174         private static function entriesExists()
 175         {
 176                 $stamp = (float)microtime(true);
 177                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 178                 self::$db_duration += (microtime(true) - $stamp);
 179                 return $exists;
 180         }
 181
 182         /**
 183          * @brief Returns the number of deferred entries in the worker queue
 184          *
 185          * @return integer Number of deferred entries in the worker queue
 186          * @throws \Exception
 187          */
 188         private static function deferredEntries()
 189         {
 190                 $stamp = (float)microtime(true);
 191                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
 192                 self::$db_duration += (microtime(true) - $stamp);
 193                 self::$db_duration_count += (microtime(true) - $stamp);
 194                 return $count;
 195         }
 196
 197         /**
 198          * @brief Returns the number of non executed entries in the worker queue
 199          *
 200          * @return integer Number of non executed entries in the worker queue
 201          * @throws \Exception
 202          */
 203         private static function totalEntries()
 204         {
 205                 $stamp = (float)microtime(true);
 206                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 207                 self::$db_duration += (microtime(true) - $stamp);
 208                 self::$db_duration_count += (microtime(true) - $stamp);
 209                 return $count;
 210         }
 211
 212         /**
 213          * @brief Returns the highest priority in the worker queue that isn't executed
 214          *
 215          * @return integer Number of active worker processes
 216          * @throws \Exception
 217          */
 218         private static function highestPriority()
 219         {
 220                 $stamp = (float)microtime(true);
 221                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 222                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 223                 self::$db_duration += (microtime(true) - $stamp);
 224                 if (DBA::isResult($workerqueue)) {
 225                         return $workerqueue["priority"];
 226                 } else {
 227                         return 0;
 228                 }
 229         }
 230
 231         /**
 232          * @brief Returns if a process with the given priority is running
 233          *
 234          * @param integer $priority The priority that should be checked
 235          *
 236          * @return integer Is there a process running with that priority?
 237          * @throws \Exception
 238          */
 239         private static function processWithPriorityActive($priority)
 240         {
 241                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 242                 return DBA::exists('workerqueue', $condition);
 243         }
 244
 245         /**
 246          * @brief Execute a worker entry
 247          *
 248          * @param array $queue Workerqueue entry
 249          *
 250          * @return boolean "true" if further processing should be stopped
 251          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 252          */
 253         public static function execute($queue)
 254         {
 255                 $a = \get_app();
 256
 257                 $mypid = getmypid();
 258
 259                 // Quit when in maintenance
 260                 if (Config::get('system', 'maintenance', false, true)) {
 261                         Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 262                         return false;
 263                 }
 264
 265                 // Constantly check the number of parallel database processes
 266                 if ($a->isMaxProcessesReached()) {
 267                         Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 268                         return false;
 269                 }
 270
 271                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 272                 if (self::maxConnectionsReached()) {
 273                         Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 274                         return false;
 275                 }
 276
 277                 $argv = json_decode($queue["parameter"], true);
 278
 279                 // Check for existance and validity of the include file
 280                 $include = $argv[0];
 281
 282                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 283                         // We constantly update the "executed" date every minute to avoid being killed too soon
 284                         if (!isset(self::$last_update)) {
 285                                 self::$last_update = strtotime($queue["executed"]);
 286                         }
 287
 288                         $age = (time() - self::$last_update) / 60;
 289                         self::$last_update = time();
 290
 291                         if ($age > 1) {
 292                                 $stamp = (float)microtime(true);
 293                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 294                                 self::$db_duration += (microtime(true) - $stamp);
 295                                 self::$db_duration_write += (microtime(true) - $stamp);
 296                         }
 297
 298                         array_shift($argv);
 299
 300                         self::execFunction($queue, $include, $argv, true);
 301
 302                         $stamp = (float)microtime(true);
 303                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 304                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 305                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 306                         }
 307                         self::$db_duration = (microtime(true) - $stamp);
 308                         self::$db_duration_write += (microtime(true) - $stamp);
 309
 310                         return true;
 311                 }
 312
 313                 // The script could be provided as full path or only with the function name
 314                 if ($include == basename($include)) {
 315                         $include = "include/".$include.".php";
 316                 }
 317
 318                 if (!validate_include($include)) {
 319                         Logger::log("Include file ".$argv[0]." is not valid!");
 320                         $stamp = (float)microtime(true);
 321                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 322                         self::$db_duration = (microtime(true) - $stamp);
 323                         self::$db_duration_write += (microtime(true) - $stamp);
 324                         return true;
 325                 }
 326
 327                 require_once $include;
 328
 329                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 330
 331                 if (function_exists($funcname)) {
 332                         // We constantly update the "executed" date every minute to avoid being killed too soon
 333                         if (!isset(self::$last_update)) {
 334                                 self::$last_update = strtotime($queue["executed"]);
 335                         }
 336
 337                         $age = (time() - self::$last_update) / 60;
 338                         self::$last_update = time();
 339
 340                         if ($age > 1) {
 341                                 $stamp = (float)microtime(true);
 342                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 343                                 self::$db_duration += (microtime(true) - $stamp);
 344                                 self::$db_duration_write += (microtime(true) - $stamp);
 345                         }
 346
 347                         self::execFunction($queue, $funcname, $argv, false);
 348
 349                         $stamp = (float)microtime(true);
 350                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 351                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 352                         }
 353                         self::$db_duration = (microtime(true) - $stamp);
 354                         self::$db_duration_write += (microtime(true) - $stamp);
 355                 } else {
 356                         Logger::log("Function ".$funcname." does not exist");
 357                         $stamp = (float)microtime(true);
 358                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 359                         self::$db_duration = (microtime(true) - $stamp);
 360                         self::$db_duration_write += (microtime(true) - $stamp);
 361                 }
 362
 363                 return true;
 364         }
 365
 366         /**
 367          * @brief Execute a function from the queue
 368          *
 369          * @param array   $queue       Workerqueue entry
 370          * @param string  $funcname    name of the function
 371          * @param array   $argv        Array of values to be passed to the function
 372          * @param boolean $method_call boolean
 373          * @return void
 374          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 375          */
 376         private static function execFunction($queue, $funcname, $argv, $method_call)
 377         {
 378                 $a = \get_app();
 379
 380                 $argc = count($argv);
 381
 382                 Logger::enableWorker($funcname);
 383
 384                 Logger::info("Process start.", ['priority' => $queue["priority"], 'id' => $queue["id"]]);
 385
 386                 $stamp = (float)microtime(true);
 387
 388                 // We use the callstack here to analyze the performance of executed worker entries.
 389                 // For this reason the variables have to be initialized.
 390                 $a->getProfiler()->reset();
 391
 392                 $a->queue = $queue;
 393
 394                 $up_duration = microtime(true) - self::$up_start;
 395
 396                 // Reset global data to avoid interferences
 397                 unset($_SESSION);
 398
 399                 // Set the workerLogger as new default logger
 400                 if ($method_call) {
 401                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 402                 } else {
 403                         $funcname($argv, $argc);
 404                 }
 405
 406                 Logger::disableWorker();
 407
 408                 unset($a->queue);
 409
 410                 $duration = (microtime(true) - $stamp);
 411
 412                 /* With these values we can analyze how effective the worker is.
 413                  * The database and rest time should be low since this is the unproductive time.
 414                  * The execution time is the productive time.
 415                  * By changing parameters like the maximum number of workers we can check the effectivness.
 416                 */
 417                 $dbtotal = round(self::$db_duration, 2);
 418                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 419                 $dbcount = round(self::$db_duration_count, 2);
 420                 $dbstat  = round(self::$db_duration_stat, 2);
 421                 $dbwrite = round(self::$db_duration_write, 2);
 422                 $dblock  = round(self::$lock_duration, 2);
 423                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 424                 $exec    = round($duration, 2);
 425
 426                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 427
 428                 self::$up_start = microtime(true);
 429                 self::$db_duration = 0;
 430                 self::$db_duration_count = 0;
 431                 self::$db_duration_stat = 0;
 432                 self::$db_duration_write = 0;
 433                 self::$lock_duration = 0;
 434
 435                 if ($duration > 3600) {
 436                         Logger::info('Longer than 1 hour.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 437                 } elseif ($duration > 600) {
 438                         Logger::info('Longer than 10 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 439                 } elseif ($duration > 300) {
 440                         Logger::info('Longer than 5 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 441                 } elseif ($duration > 120) {
 442                         Logger::info('Longer than 2 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 443                 }
 444
 445                 Logger::info('Process done.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration, 3)]);
 446
 447                 $a->getProfiler()->saveLog($a->getLogger(), "ID " . $queue["id"] . ": " . $funcname);
 448
 449                 $cooldown = Config::get("system", "worker_cooldown", 0);
 450
 451                 if ($cooldown > 0) {
 452                         Logger::info('Cooldown.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'cooldown' => $cooldown]);
 453                         sleep($cooldown);
 454                 }
 455         }
 456
 457         /**
 458          * @brief Checks if the number of database connections has reached a critical limit.
 459          *
 460          * @return bool Are more than 3/4 of the maximum connections used?
 461          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 462          */
 463         private static function maxConnectionsReached()
 464         {
 465                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 466                 $max = Config::get("system", "max_connections");
 467
 468                 // Fetch the percentage level where the worker will get active
 469                 $maxlevel = Config::get("system", "max_connections_level", 75);
 470
 471                 if ($max == 0) {
 472                         // the maximum number of possible user connections can be a system variable
 473                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 474                         if (DBA::isResult($r)) {
 475                                 $max = $r["Value"];
 476                         }
 477                         // Or it can be granted. This overrides the system variable
 478                         $stamp = (float)microtime(true);
 479                         $r = DBA::p('SHOW GRANTS');
 480                         self::$db_duration += (microtime(true) - $stamp);
 481                         while ($grants = DBA::fetch($r)) {
 482                                 $grant = array_pop($grants);
 483                                 if (stristr($grant, "GRANT USAGE ON")) {
 484                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 485                                                 $max = $match[1];
 486                                         }
 487                                 }
 488                         }
 489                         DBA::close($r);
 490                 }
 491
 492                 // If $max is set we will use the processlist to determine the current number of connections
 493                 // The processlist only shows entries of the current user
 494                 if ($max != 0) {
 495                         $stamp = (float)microtime(true);
 496                         $r = DBA::p('SHOW PROCESSLIST');
 497                         self::$db_duration += (microtime(true) - $stamp);
 498                         $used = DBA::numRows($r);
 499                         DBA::close($r);
 500
 501                         Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 502
 503                         $level = ($used / $max) * 100;
 504
 505                         if ($level >= $maxlevel) {
 506                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 507                                 return true;
 508                         }
 509                 }
 510
 511                 // We will now check for the system values.
 512                 // This limit could be reached although the user limits are fine.
 513                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 514                 if (!DBA::isResult($r)) {
 515                         return false;
 516                 }
 517                 $max = intval($r["Value"]);
 518                 if ($max == 0) {
 519                         return false;
 520                 }
 521                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 522                 if (!DBA::isResult($r)) {
 523                         return false;
 524                 }
 525                 $used = intval($r["Value"]);
 526                 if ($used == 0) {
 527                         return false;
 528                 }
 529                 Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 530
 531                 $level = $used / $max * 100;
 532
 533                 if ($level < $maxlevel) {
 534                         return false;
 535                 }
 536                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 537                 return true;
 538         }
 539
 540         /**
 541          * @brief fix the queue entry if the worker process died
 542          * @return void
 543          * @throws \Exception
 544          */
 545         private static function killStaleWorkers()
 546         {
 547                 $stamp = (float)microtime(true);
 548                 $entries = DBA::select(
 549                         'workerqueue',
 550                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 551                         ['NOT `done` AND `pid` != 0'],
 552                         ['order' => ['priority', 'created']]
 553                 );
 554                 self::$db_duration += (microtime(true) - $stamp);
 555
 556                 while ($entry = DBA::fetch($entries)) {
 557                         if (!posix_kill($entry["pid"], 0)) {
 558                                 $stamp = (float)microtime(true);
 559                                 DBA::update(
 560                                         'workerqueue',
 561                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 562                                         ['id' => $entry["id"]]
 563                                 );
 564                                 self::$db_duration += (microtime(true) - $stamp);
 565                                 self::$db_duration_write += (microtime(true) - $stamp);
 566                         } else {
 567                                 // Kill long running processes
 568                                 // Check if the priority is in a valid range
 569                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 570                                         $entry["priority"] = PRIORITY_MEDIUM;
 571                                 }
 572
 573                                 // Define the maximum durations
 574                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 575                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 576
 577                                 $argv = json_decode($entry["parameter"], true);
 578                                 $argv[0] = basename($argv[0]);
 579
 580                                 // How long is the process already running?
 581                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 582                                 if ($duration > $max_duration) {
 583                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 584                                         posix_kill($entry["pid"], SIGTERM);
 585
 586                                         // We killed the stale process.
 587                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 588                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 589                                         $new_priority = $entry["priority"];
 590                                         if ($entry["priority"] == PRIORITY_HIGH) {
 591                                                 $new_priority = PRIORITY_MEDIUM;
 592                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 593                                                 $new_priority = PRIORITY_LOW;
 594                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 595                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 596                                         }
 597                                         $stamp = (float)microtime(true);
 598                                         DBA::update(
 599                                                 'workerqueue',
 600                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 601                                                 ['id' => $entry["id"]]
 602                                         );
 603                                         self::$db_duration += (microtime(true) - $stamp);
 604                                         self::$db_duration_write += (microtime(true) - $stamp);
 605                                 } else {
 606                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 607                                 }
 608                         }
 609                 }
 610         }
 611
 612         /**
 613          * @brief Checks if the number of active workers exceeds the given limits
 614          *
 615          * @return bool Are there too much workers running?
 616          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 617          */
 618         private static function tooMuchWorkers()
 619         {
 620                 $queues = Config::get("system", "worker_queues", 10);
 621
 622                 $maxqueues = $queues;
 623
 624                 $active = self::activeWorkers();
 625
 626                 // Decrease the number of workers at higher load
 627                 $load = System::currentLoad();
 628                 if ($load) {
 629                         $maxsysload = intval(Config::get("system", "maxloadavg", 20));
 630
 631                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 632                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 633                          * For some environments, this rapid decrease is not needed.
 634                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 635                          */
 636                         $exponent = intval(Config::get('system', 'worker_load_exponent', 3));
 637                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 638                         $queues = intval(ceil($slope * $maxqueues));
 639
 640                         $processlist = '';
 641
 642                         if (Config::get('system', 'worker_jpm')) {
 643                                 $intervals = explode(',', Config::get('system', 'worker_jpm_range'));
 644                                 $jobs_per_minute = [];
 645                                 foreach ($intervals as $interval) {
 646                                         if ($interval == 0) {
 647                                                 continue;
 648                                         } else {
 649                                                 $interval = (int)$interval;
 650                                         }
 651
 652                                         $stamp = (float)microtime(true);
 653                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
 654                                         self::$db_duration += (microtime(true) - $stamp);
 655                                         self::$db_duration_stat += (microtime(true) - $stamp);
 656                                         if ($job = DBA::fetch($jobs)) {
 657                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 658                                         }
 659                                         DBA::close($jobs);
 660                                 }
 661                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 662                         }
 663
 664                         // Create a list of queue entries grouped by their priority
 665                         $listitem = [0 => ''];
 666
 667                         $idle_workers = $active;
 668
 669                         $deferred = self::deferredEntries();
 670
 671                         if (Config::get('system', 'worker_debug')) {
 672                                 $waiting_processes = 0;
 673                                 // Now adding all processes with workerqueue entries
 674                                 $stamp = (float)microtime(true);
 675                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 676                                 self::$db_duration += (microtime(true) - $stamp);
 677                                 self::$db_duration_stat += (microtime(true) - $stamp);
 678                                 while ($entry = DBA::fetch($jobs)) {
 679                                         $stamp = (float)microtime(true);
 680                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `priority` = ?", $entry["priority"]);
 681                                         self::$db_duration += (microtime(true) - $stamp);
 682                                         self::$db_duration_stat += (microtime(true) - $stamp);
 683                                         if ($process = DBA::fetch($processes)) {
 684                                                 $idle_workers -= $process["running"];
 685                                                 $waiting_processes += $entry["entries"];
 686                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 687                                         }
 688                                         DBA::close($processes);
 689                                 }
 690                                 DBA::close($jobs);
 691                         } else {
 692                                 $waiting_processes =  self::totalEntries();
 693                                 $stamp = (float)microtime(true);
 694                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` GROUP BY `priority` ORDER BY `priority`");
 695                                 self::$db_duration += (microtime(true) - $stamp);
 696                                 self::$db_duration_stat += (microtime(true) - $stamp);
 697
 698                                 while ($entry = DBA::fetch($jobs)) {
 699                                         $idle_workers -= $entry["running"];
 700                                         $listitem[$entry["priority"]] = $entry["priority"].":".$entry["running"];
 701                                 }
 702                                 DBA::close($jobs);
 703                         }
 704
 705                         $waiting_processes -= $deferred;
 706
 707                         $listitem[0] = "0:" . max(0, $idle_workers);
 708
 709                         $processlist .= ' ('.implode(', ', $listitem).')';
 710
 711                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 712                                 $top_priority = self::highestPriority();
 713                                 $high_running = self::processWithPriorityActive($top_priority);
 714
 715                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 716                                         Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 717                                         $queues = $active + 1;
 718                                 }
 719                         }
 720
 721                         Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 722
 723                         // Are there fewer workers running as possible? Then fork a new one.
 724                         if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && self::entriesExists()) {
 725                                 Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 726                                 if (Config::get('system', 'worker_daemon_mode', false)) {
 727                                         self::IPCSetJobState(true);
 728                                 } else {
 729                                         self::spawnWorker();
 730                                 }
 731                         }
 732                 }
 733
 734                 // if there are too much worker, we don't spawn a new one.
 735                 if (Config::get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 736                         self::IPCSetJobState(false);
 737                 }
 738
 739                 return $active > $queues;
 740         }
 741
 742         /**
 743          * @brief Returns the number of active worker processes
 744          *
 745          * @return integer Number of active worker processes
 746          * @throws \Exception
 747          */
 748         private static function activeWorkers()
 749         {
 750                 $stamp = (float)microtime(true);
 751                 $count = DBA::count('process', ['command' => 'Worker.php']);
 752                 self::$db_duration += (microtime(true) - $stamp);
 753                 return $count;
 754         }
 755
 756         /**
 757          * @brief Returns waiting jobs for the current process id
 758          *
 759          * @return array waiting workerqueue jobs
 760          * @throws \Exception
 761          */
 762         private static function getWaitingJobForPID()
 763         {
 764                 $stamp = (float)microtime(true);
 765                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 766                 self::$db_duration += (microtime(true) - $stamp);
 767                 if (DBA::isResult($r)) {
 768                         return DBA::toArray($r);
 769                 }
 770                 DBA::close($r);
 771
 772                 return false;
 773         }
 774
 775         /**
 776          * @brief Returns the next jobs that should be executed
 777          *
 778          * @return array array with next jobs
 779          * @throws \Exception
 780          */
 781         private static function nextProcess()
 782         {
 783                 $priority = self::nextPriority();
 784                 if (empty($priority)) {
 785                         Logger::info('No tasks found');
 786                         return [];
 787                 }
 788
 789                 $limit = Config::get('system', 'worker_fetch_limit', 1);
 790
 791                 $ids = [];
 792                 $stamp = (float)microtime(true);
 793                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 794                 $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['created']]);
 795                 self::$db_duration += (microtime(true) - $stamp);
 796                 while ($task = DBA::fetch($tasks)) {
 797                         $ids[] = $task['id'];
 798                         // Only continue that loop while we are storing commands that can be processed quickly
 799                         $command = json_decode($task['parameter'])[0];
 800                         if (!in_array($command, self::FAST_COMMANDS)) {
 801                                 break;
 802                         }
 803                 }
 804                 DBA::close($tasks);
 805
 806                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
 807                 return $ids;
 808         }
 809
 810         /**
 811          * @brief Returns the priority of the next workerqueue job
 812          *
 813          * @return string priority
 814          * @throws \Exception
 815          */
 816         private static function nextPriority()
 817         {
 818                 $waiting = [];
 819                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
 820                 foreach ($priorities as $priority) {
 821                         $stamp = (float)microtime(true);
 822                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 823                                 $waiting[$priority] = true;
 824                         }
 825                         self::$db_duration += (microtime(true) - $stamp);
 826                 }
 827
 828                 if (!empty($waiting[PRIORITY_CRITICAL])) {
 829                         return PRIORITY_CRITICAL;
 830                 }
 831
 832                 $running = [];
 833                 $running_total = 0;
 834                 $stamp = (float)microtime(true);
 835                 $processes = DBA::p("SELECT COUNT(DISTINCT(`process`.`pid`)) AS `running`, `priority` FROM `process`
 836                         INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
 837                         WHERE NOT `done` GROUP BY `priority`");
 838                 self::$db_duration += (microtime(true) - $stamp);
 839                 while ($process = DBA::fetch($processes)) {
 840                         $running[$process['priority']] = $process['running'];
 841                         $running_total += $process['running'];
 842                 }
 843                 DBA::close($processes);
 844
 845                 foreach ($priorities as $priority) {
 846                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 847                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 848                                 return $priority;
 849                         }
 850                 }
 851
 852                 $active = max(self::activeWorkers(), $running_total);
 853                 $priorities = max(count($waiting), count($running));
 854                 $exponent = 2;
 855
 856                 $total = 0;
 857                 for ($i = 1; $i <= $priorities; ++$i) {
 858                         $total += pow($i, $exponent);
 859                 }
 860
 861                 $limit = [];
 862                 for ($i = 1; $i <= $priorities; ++$i) {
 863                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 864                 }
 865
 866                 $i = 0;
 867                 foreach ($running as $priority => $workers) {
 868                         if ($workers < $limit[$i++]) {
 869                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 870                                 return $priority;
 871                         }
 872                 }
 873
 874                 if (!empty($waiting)) {
 875                         $priority = array_keys($waiting)[0];
 876                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
 877                         return $priority;
 878                 }
 879
 880                 return false;
 881         }
 882
 883         /**
 884          * @brief Find and claim the next worker process for us
 885          *
 886          * @return boolean Have we found something?
 887          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 888          */
 889         private static function findWorkerProcesses()
 890         {
 891                 $mypid = getmypid();
 892
 893                 $ids = self::nextProcess();
 894
 895                 // If there is no result we check without priority limit
 896                 if (empty($ids)) {
 897                         $limit = Config::get('system', 'worker_fetch_limit', 1);
 898
 899                         $stamp = (float)microtime(true);
 900                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 901                         $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'created']]);
 902                         self::$db_duration += (microtime(true) - $stamp);
 903
 904                         while ($task = DBA::fetch($tasks)) {
 905                                 $ids[] = $task['id'];
 906                                 // Only continue that loop while we are storing commands that can be processed quickly
 907                                 $command = json_decode($task['parameter'])[0];
 908                                 if (!in_array($command, self::FAST_COMMANDS)) {
 909                                         break;
 910                                 }
 911                         }
 912                         DBA::close($tasks);
 913                 }
 914
 915                 if (!empty($ids)) {
 916                         $stamp = (float)microtime(true);
 917                         $condition = ['id' => $ids, 'done' => false, 'pid' => 0];
 918                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $condition);
 919                         self::$db_duration += (microtime(true) - $stamp);
 920                         self::$db_duration_write += (microtime(true) - $stamp);
 921                 }
 922
 923                 return !empty($ids);
 924         }
 925
 926         /**
 927          * @brief Returns the next worker process
 928          *
 929          * @return string SQL statement
 930          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 931          */
 932         public static function workerProcess()
 933         {
 934                 // There can already be jobs for us in the queue.
 935                 $waiting = self::getWaitingJobForPID();
 936                 if (!empty($waiting)) {
 937                         return $waiting;
 938                 }
 939
 940                 $stamp = (float)microtime(true);
 941                 if (!Lock::acquire('worker_process')) {
 942                         return false;
 943                 }
 944                 self::$lock_duration += (microtime(true) - $stamp);
 945
 946                 $found = self::findWorkerProcesses();
 947
 948                 Lock::release('worker_process');
 949
 950                 if ($found) {
 951                         $stamp = (float)microtime(true);
 952                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 953                         self::$db_duration += (microtime(true) - $stamp);
 954                         return DBA::toArray($r);
 955                 }
 956                 return false;
 957         }
 958
 959         /**
 960          * @brief Removes a workerqueue entry from the current process
 961          * @return void
 962          * @throws \Exception
 963          */
 964         public static function unclaimProcess()
 965         {
 966                 $mypid = getmypid();
 967
 968                 $stamp = (float)microtime(true);
 969                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 970                 self::$db_duration += (microtime(true) - $stamp);
 971                 self::$db_duration_write += (microtime(true) - $stamp);
 972         }
 973
 974         /**
 975          * @brief Call the front end worker
 976          * @return void
 977          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 978          */
 979         public static function callWorker()
 980         {
 981                 if (!Config::get("system", "frontend_worker")) {
 982                         return;
 983                 }
 984
 985                 $url = System::baseUrl()."/worker";
 986                 Network::fetchUrl($url, false, 1);
 987         }
 988
 989         /**
 990          * @brief Call the front end worker if there aren't any active
 991          * @return void
 992          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 993          */
 994         public static function executeIfIdle()
 995         {
 996                 if (!Config::get("system", "frontend_worker")) {
 997                         return;
 998                 }
 999
1000                 // Do we have "proc_open"? Then we can fork the worker
1001                 if (function_exists("proc_open")) {
1002                         // When was the last time that we called the worker?
1003                         // Less than one minute? Then we quit
1004                         if ((time() - Config::get("system", "worker_started")) < 60) {
1005                                 return;
1006                         }
1007
1008                         Config::set("system", "worker_started", time());
1009
1010                         // Do we have enough running workers? Then we quit here.
1011                         if (self::tooMuchWorkers()) {
1012                                 // Cleaning dead processes
1013                                 self::killStaleWorkers();
1014                                 Process::deleteInactive();
1015
1016                                 return;
1017                         }
1018
1019                         self::runCron();
1020
1021                         Logger::log('Call worker', Logger::DEBUG);
1022                         self::spawnWorker();
1023                         return;
1024                 }
1025
1026                 // We cannot execute background processes.
1027                 // We now run the processes from the frontend.
1028                 // This won't work with long running processes.
1029                 self::runCron();
1030
1031                 self::clearProcesses();
1032
1033                 $workers = self::activeWorkers();
1034
1035                 if ($workers == 0) {
1036                         self::callWorker();
1037                 }
1038         }
1039
1040         /**
1041          * @brief Removes long running worker processes
1042          * @return void
1043          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1044          */
1045         public static function clearProcesses()
1046         {
1047                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
1048
1049                 /// @todo We should clean up the corresponding workerqueue entries as well
1050                 $stamp = (float)microtime(true);
1051                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1052                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1053                 DBA::delete('process', $condition);
1054                 self::$db_duration = (microtime(true) - $stamp);
1055                 self::$db_duration_write += (microtime(true) - $stamp);
1056         }
1057
1058         /**
1059          * @brief Runs the cron processes
1060          * @return void
1061          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1062          */
1063         private static function runCron()
1064         {
1065                 Logger::log('Add cron entries', Logger::DEBUG);
1066
1067                 // Check for spooled items
1068                 self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
1069
1070                 // Run the cron job that calls all other jobs
1071                 self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
1072
1073                 // Cleaning dead processes
1074                 self::killStaleWorkers();
1075         }
1076
1077         /**
1078          * @brief Spawns a new worker
1079          * @param bool $do_cron
1080          * @return void
1081          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1082          */
1083         public static function spawnWorker($do_cron = false)
1084         {
1085                 $command = 'bin/worker.php';
1086
1087                 $args = ['no_cron' => !$do_cron];
1088
1089                 $a = get_app();
1090                 $process = new Core\Process($a->getLogger(), $a->getMode(), $a->getConfig(), $a->getBasePath());
1091                 $process->run($command, $args);
1092
1093                 // after spawning we have to remove the flag.
1094                 if (Config::get('system', 'worker_daemon_mode', false)) {
1095                         self::IPCSetJobState(false);
1096                 }
1097         }
1098
1099         /**
1100          * @brief Adds tasks to the worker queue
1101          *
1102          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1103          *
1104          * next args are passed as $cmd command line
1105          * or: Worker::add(PRIORITY_HIGH, "Notifier", Delivery::DELETION, $drop_id);
1106          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1107          *
1108          * @return boolean "false" if worker queue entry already existed or there had been an error
1109          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1110          * @note $cmd and string args are surrounded with ""
1111          *
1112          * @hooks 'proc_run'
1113          *    array $arr
1114          *
1115          */
1116         public static function add($cmd)
1117         {
1118                 $args = func_get_args();
1119
1120                 if (!count($args)) {
1121                         return false;
1122                 }
1123
1124                 $arr = ['args' => $args, 'run_cmd' => true];
1125
1126                 Hook::callAll("proc_run", $arr);
1127                 if (!$arr['run_cmd'] || !count($args)) {
1128                         return true;
1129                 }
1130
1131                 $priority = PRIORITY_MEDIUM;
1132                 // Don't fork from frontend tasks by default
1133                 $dont_fork = Config::get("system", "worker_dont_fork", false) || !\get_app()->getMode()->isBackend();
1134                 $created = DateTimeFormat::utcNow();
1135                 $force_priority = false;
1136
1137                 $run_parameter = array_shift($args);
1138
1139                 if (is_int($run_parameter)) {
1140                         $priority = $run_parameter;
1141                 } elseif (is_array($run_parameter)) {
1142                         if (isset($run_parameter['priority'])) {
1143                                 $priority = $run_parameter['priority'];
1144                         }
1145                         if (isset($run_parameter['created'])) {
1146                                 $created = $run_parameter['created'];
1147                         }
1148                         if (isset($run_parameter['dont_fork'])) {
1149                                 $dont_fork = $run_parameter['dont_fork'];
1150                         }
1151                         if (isset($run_parameter['force_priority'])) {
1152                                 $force_priority = $run_parameter['force_priority'];
1153                         }
1154                 }
1155
1156                 $parameters = json_encode($args);
1157                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1158                 $added = false;
1159
1160                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1161                 if (DBA::errorNo() != 0) {
1162                         return false;
1163                 }
1164
1165                 if (!$found) {
1166                         $added = DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1167                         if (!$added) {
1168                                 return false;
1169                         }
1170                 } elseif ($force_priority) {
1171                         DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
1172                 }
1173
1174                 // Should we quit and wait for the worker to be called as a cronjob?
1175                 if ($dont_fork) {
1176                         return $added;
1177                 }
1178
1179                 // If there is a lock then we don't have to check for too much worker
1180                 if (!Lock::acquire('worker', 0)) {
1181                         return $added;
1182                 }
1183
1184                 // If there are already enough workers running, don't fork another one
1185                 $quit = self::tooMuchWorkers();
1186                 Lock::release('worker');
1187
1188                 if ($quit) {
1189                         return $added;
1190                 }
1191
1192                 // We tell the daemon that a new job entry exists
1193                 if (Config::get('system', 'worker_daemon_mode', false)) {
1194                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1195                         return $added;
1196                 }
1197
1198                 // Now call the worker to execute the jobs that we just added to the queue
1199                 self::spawnWorker();
1200
1201                 return $added;
1202         }
1203
1204         /**
1205          * Returns the next retrial level for worker jobs.
1206          * This function will skip levels when jobs are older.
1207          *
1208          * @param array $queue Worker queue entry
1209          * @param integer $max_level maximum retrial level
1210          * @return integer the next retrial level value
1211          */
1212         private static function getNextRetrial($queue, $max_level)
1213         {
1214                 $created = strtotime($queue['created']);
1215                 $retrial_time = time() - $created;
1216
1217                 $new_retrial = $queue['retrial'] + 1;
1218                 $total = 0;
1219                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1220                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1221                         $total += $delay;
1222                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1223                                 $new_retrial = $retrial;
1224                         }
1225                 }
1226                 Logger::info('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1227                 return $new_retrial;
1228         }
1229
1230         /**
1231          * Defers the current worker entry
1232          * @return boolean had the entry been deferred?
1233          */
1234         public static function defer()
1235         {
1236                 if (empty(DI::app()->queue)) {
1237                         return false;
1238                 }
1239
1240                 $queue = DI::app()->queue;
1241
1242                 $retrial = $queue['retrial'];
1243                 $id = $queue['id'];
1244                 $priority = $queue['priority'];
1245
1246                 $max_level = Config::get('system', 'worker_defer_limit');
1247
1248                 $new_retrial = self::getNextRetrial($queue, $max_level);
1249
1250                 if ($new_retrial > $max_level) {
1251                         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]);
1252                         return false;
1253                 }
1254
1255                 // Calculate the delay until the next trial
1256                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1257                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1258
1259                 if (($priority < PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1260                         $priority = PRIORITY_MEDIUM;
1261                 } elseif (($priority < PRIORITY_LOW) && ($new_retrial > 6)) {
1262                         $priority = PRIORITY_LOW;
1263                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1264                         $priority = PRIORITY_NEGLIGIBLE;
1265                 }
1266
1267                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1268
1269                 $stamp = (float)microtime(true);
1270                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1271                 DBA::update('workerqueue', $fields, ['id' => $id]);
1272                 self::$db_duration += (microtime(true) - $stamp);
1273                 self::$db_duration_write += (microtime(true) - $stamp);
1274
1275                 return true;
1276         }
1277
1278         /**
1279          * Log active processes into the "process" table
1280          *
1281          * @brief Log active processes into the "process" table
1282          */
1283         public static function startProcess()
1284         {
1285                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1286
1287                 $command = basename($trace[0]['file']);
1288
1289                 Process::deleteInactive();
1290
1291                 Process::insert($command);
1292         }
1293
1294         /**
1295          * Remove the active process from the "process" table
1296          *
1297          * @brief Remove the active process from the "process" table
1298          * @return bool
1299          * @throws \Exception
1300          */
1301         public static function endProcess()
1302         {
1303                 return Process::deleteByPid();
1304         }
1305
1306         /**
1307          * Set the flag if some job is waiting
1308          *
1309          * @brief Set the flag if some job is waiting
1310          * @param boolean $jobs Is there a waiting job?
1311          * @throws \Exception
1312          */
1313         public static function IPCSetJobState($jobs)
1314         {
1315                 $stamp = (float)microtime(true);
1316                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1317                 self::$db_duration += (microtime(true) - $stamp);
1318                 self::$db_duration_write += (microtime(true) - $stamp);
1319         }
1320
1321         /**
1322          * Checks if some worker job waits to be executed
1323          *
1324          * @brief Checks if some worker job waits to be executed
1325          * @return bool
1326          * @throws \Exception
1327          */
1328         public static function IPCJobsExists()
1329         {
1330                 $stamp = (float)microtime(true);
1331                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1332                 self::$db_duration += (microtime(true) - $stamp);
1333
1334                 // When we don't have a row, no job is running
1335                 if (!DBA::isResult($row)) {
1336                         return false;
1337                 }
1338
1339                 return (bool)$row['jobs'];
1340         }
1341 }