src/Core/Worker.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Core;
  23
  24 use Friendica\Core\Worker\Entity\Process;
  25 use Friendica\Database\DBA;
  26 use Friendica\DI;
  27 use Friendica\Util\DateTimeFormat;
  28
  29 /**
  30  * Contains the class for the worker background job processing
  31  */
  32 class Worker
  33 {
  34         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
  35         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
  36         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
  37         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
  38
  39         const FAST_COMMANDS = ['APDelivery', 'Delivery'];
  40
  41         const LOCK_PROCESS = 'worker_process';
  42         const LOCK_WORKER = 'worker';
  43
  44         private static $up_start;
  45         private static $db_duration = 0;
  46         private static $db_duration_count = 0;
  47         private static $db_duration_write = 0;
  48         private static $db_duration_stat = 0;
  49         private static $lock_duration = 0;
  50         private static $last_update;
  51         private static $state;
  52         /** @var Process */
  53         private static $process;
  54
  55         /**
  56          * Processes the tasks that are in the workerqueue table
  57          *
  58          * @param boolean $run_cron Should the cron processes be executed?
  59          * @param Process $process  The current running process
  60          * @return void
  61          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  62          */
  63         public static function processQueue(bool $run_cron, Process $process)
  64         {
  65                 self::$up_start = microtime(true);
  66
  67                 // At first check the maximum load. We shouldn't continue with a high load
  68                 if (DI::system()->isMaxLoadReached()) {
  69                         Logger::notice('Pre check: maximum load reached, quitting.');
  70                         return;
  71                 }
  72
  73                 // We now start the process. This is done after the load check since this could increase the load.
  74                 self::$process = $process;
  75
  76                 // Kill stale processes every 5 minutes
  77                 $last_cleanup = DI::config()->get('system', 'worker_last_cleaned', 0);
  78                 if (time() > ($last_cleanup + 300)) {
  79                         DI::config()->set('system', 'worker_last_cleaned', time());
  80                         Worker\Cron::killStaleWorkers();
  81                 }
  82
  83                 // Check if the system is ready
  84                 if (!self::isReady()) {
  85                         return;
  86                 }
  87
  88                 // Now we start additional cron processes if we should do so
  89                 if ($run_cron) {
  90                         Worker\Cron::run();
  91                 }
  92
  93                 $last_check = $starttime = time();
  94                 self::$state = self::STATE_STARTUP;
  95
  96                 // We fetch the next queue entry that is about to be executed
  97                 while ($r = self::workerProcess()) {
  98                         if (Worker\IPC::JobsExists(getmypid())) {
  99                                 Worker\IPC::DeleteJobState(getmypid());
 100                         }
 101
 102                         // Don't refetch when a worker fetches tasks for multiple workers
 103                         $refetched = DI::config()->get('system', 'worker_multiple_fetch');
 104                         foreach ($r as $entry) {
 105                                 // The work will be done
 106                                 if (!self::execute($entry)) {
 107                                         Logger::warning('Process execution failed, quitting.', ['entry' => $entry]);
 108                                         return;
 109                                 }
 110
 111                                 // Trying to fetch new processes - but only once when successful
 112                                 if (!$refetched && DI::lock()->acquire(self::LOCK_PROCESS, 0)) {
 113                                         self::findWorkerProcesses();
 114                                         DI::lock()->release(self::LOCK_PROCESS);
 115                                         self::$state = self::STATE_REFETCH;
 116                                         $refetched = true;
 117                                 } else {
 118                                         self::$state = self::STATE_SHORT_LOOP;
 119                                 }
 120                         }
 121
 122                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 123                         if ((time() > $last_check + 5) && !self::getWaitingJobForPID()) {
 124                                 self::$state = self::STATE_LONG_LOOP;
 125
 126                                 if (DI::lock()->acquire(self::LOCK_WORKER, 0)) {
 127                                 // Count active workers and compare them with a maximum value that depends on the load
 128                                         if (self::tooMuchWorkers()) {
 129                                                 Logger::notice('Active worker limit reached, quitting.');
 130                                                 DI::lock()->release(self::LOCK_WORKER);
 131                                                 return;
 132                                         }
 133
 134                                         // Check free memory
 135                                         if (DI::system()->isMinMemoryReached()) {
 136                                                 Logger::warning('Memory limit reached, quitting.');
 137                                                 DI::lock()->release(self::LOCK_WORKER);
 138                                                 return;
 139                                         }
 140                                         DI::lock()->release(self::LOCK_WORKER);
 141                                 }
 142                                 $last_check = time();
 143                         }
 144
 145                         // Quit the worker once every cron interval
 146                         if (time() > ($starttime + (DI::config()->get('system', 'cron_interval') * 60))) {
 147                                 Logger::info('Process lifetime reached, respawning.');
 148                                 self::unclaimProcess($process);
 149                                 if (Worker\Daemon::isMode()) {
 150                                         Worker\IPC::SetJobState(true);
 151                                 } else {
 152                                         self::spawnWorker();
 153                                 }
 154                                 return;
 155                         }
 156                 }
 157
 158                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 159                 if (Worker\Daemon::isMode()) {
 160                         Worker\IPC::SetJobState(false);
 161                 }
 162                 Logger::info("Couldn't select a workerqueue entry, quitting process", ['pid' => getmypid()]);
 163         }
 164
 165         /**
 166          * Checks if the system is ready.
 167          *
 168          * Several system parameters like memory, connections and processes are checked.
 169          *
 170          * @return boolean
 171          */
 172         public static function isReady(): bool
 173         {
 174                 // Count active workers and compare them with a maximum value that depends on the load
 175                 if (self::tooMuchWorkers()) {
 176                         Logger::notice('Active worker limit reached, quitting.');
 177                         return false;
 178                 }
 179
 180                 // Do we have too few memory?
 181                 if (DI::system()->isMinMemoryReached()) {
 182                         Logger::warning('Memory limit reached, quitting.');
 183                         return false;
 184                 }
 185
 186                 // Possibly there are too much database connections
 187                 if (self::maxConnectionsReached()) {
 188                         Logger::warning('Maximum connections reached, quitting.');
 189                         return false;
 190                 }
 191
 192                 // Possibly there are too much database processes that block the system
 193                 if (DI::system()->isMaxProcessesReached()) {
 194                         Logger::warning('Maximum processes reached, quitting.');
 195                         return false;
 196                 }
 197
 198                 return true;
 199         }
 200
 201         /**
 202          * Check if non executed tasks do exist in the worker queue
 203          *
 204          * @return boolean Returns "true" if tasks are existing
 205          * @throws \Exception
 206          */
 207         public static function entriesExists(): bool
 208         {
 209                 $stamp = (float)microtime(true);
 210                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 211                 self::$db_duration += (microtime(true) - $stamp);
 212                 return $exists;
 213         }
 214
 215         /**
 216          * Returns the number of deferred entries in the worker queue
 217          *
 218          * @return integer Number of deferred entries in the worker queue
 219          * @throws \Exception
 220          */
 221         private static function deferredEntries(): int
 222         {
 223                 $stamp = (float)microtime(true);
 224                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
 225                 self::$db_duration += (microtime(true) - $stamp);
 226                 self::$db_duration_count += (microtime(true) - $stamp);
 227                 return $count;
 228         }
 229
 230         /**
 231          * Returns the number of non executed entries in the worker queue
 232          *
 233          * @return integer Number of non executed entries in the worker queue
 234          * @throws \Exception
 235          */
 236         private static function totalEntries(): int
 237         {
 238                 $stamp = (float)microtime(true);
 239                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 240                 self::$db_duration += (microtime(true) - $stamp);
 241                 self::$db_duration_count += (microtime(true) - $stamp);
 242                 return $count;
 243         }
 244
 245         /**
 246          * Returns the highest priority in the worker queue that isn't executed
 247          *
 248          * @return integer Number of active worker processes
 249          * @throws \Exception
 250          */
 251         private static function highestPriority(): int
 252         {
 253                 $stamp = (float)microtime(true);
 254                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 255                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 256                 self::$db_duration += (microtime(true) - $stamp);
 257                 if (DBA::isResult($workerqueue)) {
 258                         return $workerqueue['priority'];
 259                 } else {
 260                         return 0;
 261                 }
 262         }
 263
 264         /**
 265          * Returns if a process with the given priority is running
 266          *
 267          * @param integer $priority The priority that should be checked
 268          *
 269          * @return integer Is there a process running with that priority?
 270          * @throws \Exception
 271          */
 272         private static function processWithPriorityActive(int $priority): int
 273         {
 274                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 275                 return DBA::exists('workerqueue', $condition);
 276         }
 277
 278         /**
 279          * Checks if the given file is valid to be included
 280          *
 281          * @param mixed $file
 282          * @return bool
 283          */
 284         private static function validateInclude(&$file): bool
 285         {
 286                 $orig_file = $file;
 287
 288                 $file = realpath($file);
 289
 290                 if (strpos($file, getcwd()) !== 0) {
 291                         return false;
 292                 }
 293
 294                 $file = str_replace(getcwd() . '/', '', $file, $count);
 295                 if ($count != 1) {
 296                         return false;
 297                 }
 298
 299                 if ($orig_file !== $file) {
 300                         return false;
 301                 }
 302
 303                 $valid = false;
 304                 if (strpos($file, 'include/') === 0) {
 305                         $valid = true;
 306                 }
 307
 308                 if (strpos($file, 'addon/') === 0) {
 309                         $valid = true;
 310                 }
 311
 312                 // Simply return flag
 313                 return $valid;
 314         }
 315
 316         /**
 317          * Execute a worker entry
 318          *
 319          * @param array $queue Workerqueue entry
 320          *
 321          * @return boolean "true" if further processing should be stopped
 322          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 323          */
 324         public static function execute(array $queue): bool
 325         {
 326                 $mypid = getmypid();
 327
 328                 // Quit when in maintenance
 329                 if (DI::config()->get('system', 'maintenance', false, true)) {
 330                         Logger::notice('Maintenance mode - quit process', ['pid' => $mypid]);
 331                         return false;
 332                 }
 333
 334                 // Constantly check the number of parallel database processes
 335                 if (DI::system()->isMaxProcessesReached()) {
 336                         Logger::warning('Max processes reached for process', ['pid' => $mypid]);
 337                         return false;
 338                 }
 339
 340                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 341                 if (self::maxConnectionsReached()) {
 342                         Logger::warning('Max connection reached for process', ['pid' => $mypid]);
 343                         return false;
 344                 }
 345
 346                 $argv = json_decode($queue['parameter'], true);
 347                 if (!is_array($argv)) {
 348                         $argv = [];
 349                 }
 350
 351                 if (!empty($queue['command'])) {
 352                         array_unshift($argv, $queue['command']);
 353                 }
 354
 355                 if (empty($argv)) {
 356                         Logger::warning('Parameter is empty', ['queue' => $queue]);
 357                         return false;
 358                 }
 359
 360                 // Check for existance and validity of the include file
 361                 $include = $argv[0];
 362
 363                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 364                         // We constantly update the "executed" date every minute to avoid being killed too soon
 365                         if (!isset(self::$last_update)) {
 366                                 self::$last_update = strtotime($queue['executed']);
 367                         }
 368
 369                         $age = (time() - self::$last_update) / 60;
 370                         self::$last_update = time();
 371
 372                         if ($age > 1) {
 373                                 $stamp = (float)microtime(true);
 374                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 375                                 self::$db_duration += (microtime(true) - $stamp);
 376                                 self::$db_duration_write += (microtime(true) - $stamp);
 377                         }
 378
 379                         array_shift($argv);
 380
 381                         self::execFunction($queue, $include, $argv, true);
 382
 383                         $stamp = (float)microtime(true);
 384                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 385                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 386                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 387                         }
 388                         self::$db_duration = (microtime(true) - $stamp);
 389                         self::$db_duration_write += (microtime(true) - $stamp);
 390
 391                         return true;
 392                 }
 393
 394                 // The script could be provided as full path or only with the function name
 395                 if ($include == basename($include)) {
 396                         $include = 'include/' . $include . '.php';
 397                 }
 398
 399                 if (!self::validateInclude($include)) {
 400                         Logger::warning('Include file is not valid', ['file' => $argv[0]]);
 401                         $stamp = (float)microtime(true);
 402                         DBA::delete('workerqueue', ['id' => $queue['id']]);
 403                         self::$db_duration = (microtime(true) - $stamp);
 404                         self::$db_duration_write += (microtime(true) - $stamp);
 405                         return true;
 406                 }
 407
 408                 require_once $include;
 409
 410                 $funcname = str_replace('.php', '', basename($argv[0])) .'_run';
 411
 412                 if (function_exists($funcname)) {
 413                         // We constantly update the "executed" date every minute to avoid being killed too soon
 414                         if (!isset(self::$last_update)) {
 415                                 self::$last_update = strtotime($queue['executed']);
 416                         }
 417
 418                         $age = (time() - self::$last_update) / 60;
 419                         self::$last_update = time();
 420
 421                         if ($age > 1) {
 422                                 $stamp = (float)microtime(true);
 423                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 424                                 self::$db_duration += (microtime(true) - $stamp);
 425                                 self::$db_duration_write += (microtime(true) - $stamp);
 426                         }
 427
 428                         self::execFunction($queue, $funcname, $argv, false);
 429
 430                         $stamp = (float)microtime(true);
 431                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue['id']])) {
 432                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 433                         }
 434                         self::$db_duration = (microtime(true) - $stamp);
 435                         self::$db_duration_write += (microtime(true) - $stamp);
 436                 } else {
 437                         Logger::warning('Function does not exist', ['function' => $funcname]);
 438                         $stamp = (float)microtime(true);
 439                         DBA::delete('workerqueue', ['id' => $queue['id']]);
 440                         self::$db_duration = (microtime(true) - $stamp);
 441                         self::$db_duration_write += (microtime(true) - $stamp);
 442                 }
 443
 444                 return true;
 445         }
 446
 447         /**
 448          * Execute a function from the queue
 449          *
 450          * @param array   $queue       Workerqueue entry
 451          * @param string  $funcname    name of the function
 452          * @param array   $argv        Array of values to be passed to the function
 453          * @param boolean $method_call boolean
 454          * @return void
 455          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 456          */
 457         private static function execFunction(array $queue, string $funcname, array $argv, bool $method_call)
 458         {
 459                 $a = DI::app();
 460
 461                 $cooldown = DI::config()->get('system', 'worker_cooldown', 0);
 462                 if ($cooldown > 0) {
 463                         Logger::debug('Pre execution cooldown.', ['cooldown' => $cooldown, 'id' => $queue['id'], 'priority' => $queue['priority'], 'command' => $queue['command']]);
 464                         sleep($cooldown);
 465                 }
 466
 467                 $load_cooldown      = DI::config()->get('system', 'worker_load_cooldown');
 468                 $processes_cooldown = DI::config()->get('system', 'worker_processes_cooldown');
 469
 470                 while ((($load_cooldown > 0) || ($processes_cooldown > 0)) && ($load = System::getLoadAvg())) {
 471                         if (($load_cooldown > 0) && ($load['average1'] > $load_cooldown)) {
 472                                 Logger::debug('Load induced pre execution cooldown.', ['max' => $load_cooldown, 'load' => $load, 'id' => $queue['id'], 'priority' => $queue['priority'], 'command' => $queue['command']]);
 473                                 sleep(1);
 474                                 continue;
 475                         }
 476                         if (($processes_cooldown > 0) && ($load['scheduled'] > $processes_cooldown)) {
 477                                 Logger::debug('Process induced pre execution cooldown.', ['max' => $processes_cooldown, 'load' => $load, 'id' => $queue['id'], 'priority' => $queue['priority'], 'command' => $queue['command']]);
 478                                 sleep(1);
 479                                 continue;
 480                         }
 481                         break;
 482                 }
 483
 484                 Logger::enableWorker($funcname);
 485
 486                 Logger::info('Process start.', ['priority' => $queue['priority'], 'id' => $queue['id']]);
 487
 488                 $stamp = (float)microtime(true);
 489
 490                 // We use the callstack here to analyze the performance of executed worker entries.
 491                 // For this reason the variables have to be initialized.
 492                 DI::profiler()->reset();
 493
 494                 $a->setQueue($queue);
 495
 496                 $up_duration = microtime(true) - self::$up_start;
 497
 498                 // Reset global data to avoid interferences
 499                 unset($_SESSION);
 500
 501                 // Set the workerLogger as new default logger
 502                 if ($method_call) {
 503                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 504                 } else {
 505                         $funcname($argv, count($argv));
 506                 }
 507
 508                 Logger::disableWorker();
 509
 510                 $a->setQueue([]);
 511
 512                 $duration = (microtime(true) - $stamp);
 513
 514                 /* With these values we can analyze how effective the worker is.
 515                  * The database and rest time should be low since this is the unproductive time.
 516                  * The execution time is the productive time.
 517                  * By changing parameters like the maximum number of workers we can check the effectivness.
 518                 */
 519                 $dbtotal = round(self::$db_duration, 2);
 520                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 521                 $dbcount = round(self::$db_duration_count, 2);
 522                 $dbstat  = round(self::$db_duration_stat, 2);
 523                 $dbwrite = round(self::$db_duration_write, 2);
 524                 $dblock  = round(self::$lock_duration, 2);
 525                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 526                 $exec    = round($duration, 2);
 527
 528                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 529
 530                 self::$up_start = microtime(true);
 531                 self::$db_duration = 0;
 532                 self::$db_duration_count = 0;
 533                 self::$db_duration_stat = 0;
 534                 self::$db_duration_write = 0;
 535                 self::$lock_duration = 0;
 536
 537                 if ($duration > 3600) {
 538                         Logger::info('Longer than 1 hour.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 539                 } elseif ($duration > 600) {
 540                         Logger::info('Longer than 10 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 541                 } elseif ($duration > 300) {
 542                         Logger::info('Longer than 5 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 543                 } elseif ($duration > 120) {
 544                         Logger::info('Longer than 2 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 545                 }
 546
 547                 Logger::info('Process done.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration, 3)]);
 548
 549                 DI::profiler()->saveLog(DI::logger(), 'ID ' . $queue['id'] . ': ' . $funcname);
 550
 551                 if ($cooldown > 0) {
 552                         Logger::info('Post execution cooldown.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'cooldown' => $cooldown]);
 553                         sleep($cooldown);
 554                 }
 555         }
 556
 557         /**
 558          * Checks if the number of database connections has reached a critical limit.
 559          *
 560          * @return bool Are more than 3/4 of the maximum connections used?
 561          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 562          */
 563         private static function maxConnectionsReached(): bool
 564         {
 565                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 566                 $max = DI::config()->get('system', 'max_connections');
 567
 568                 // Fetch the percentage level where the worker will get active
 569                 $maxlevel = DI::config()->get('system', 'max_connections_level', 75);
 570
 571                 if ($max == 0) {
 572                         // the maximum number of possible user connections can be a system variable
 573                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 574                         if (DBA::isResult($r)) {
 575                                 $max = $r['Value'];
 576                         }
 577                         // Or it can be granted. This overrides the system variable
 578                         $stamp = (float)microtime(true);
 579                         $r = DBA::p('SHOW GRANTS');
 580                         self::$db_duration += (microtime(true) - $stamp);
 581                         while ($grants = DBA::fetch($r)) {
 582                                 $grant = array_pop($grants);
 583                                 if (stristr($grant, "GRANT USAGE ON")) {
 584                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 585                                                 $max = $match[1];
 586                                         }
 587                                 }
 588                         }
 589                         DBA::close($r);
 590                 }
 591
 592                 // If $max is set we will use the processlist to determine the current number of connections
 593                 // The processlist only shows entries of the current user
 594                 if ($max != 0) {
 595                         $stamp = (float)microtime(true);
 596                         $r = DBA::p('SHOW PROCESSLIST');
 597                         self::$db_duration += (microtime(true) - $stamp);
 598                         $used = DBA::numRows($r);
 599                         DBA::close($r);
 600
 601                         Logger::info('Connection usage (user values)', ['usage' => $used, 'max' => $max]);
 602
 603                         $level = ($used / $max) * 100;
 604
 605                         if ($level >= $maxlevel) {
 606                                 Logger::warning('Maximum level (' . $maxlevel . '%) of user connections reached: ' . $used .'/' . $max);
 607                                 return true;
 608                         }
 609                 }
 610
 611                 // We will now check for the system values.
 612                 // This limit could be reached although the user limits are fine.
 613                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 614                 if (!DBA::isResult($r)) {
 615                         return false;
 616                 }
 617                 $max = intval($r['Value']);
 618                 if ($max == 0) {
 619                         return false;
 620                 }
 621                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 622                 if (!DBA::isResult($r)) {
 623                         return false;
 624                 }
 625                 $used = intval($r['Value']);
 626                 if ($used == 0) {
 627                         return false;
 628                 }
 629                 Logger::info('Connection usage (system values)', ['used' => $used, 'max' => $max]);
 630
 631                 $level = $used / $max * 100;
 632
 633                 if ($level < $maxlevel) {
 634                         return false;
 635                 }
 636                 Logger::warning('Maximum level (' . $level . '%) of system connections reached: ' . $used . '/' . $max);
 637                 return true;
 638         }
 639
 640
 641         /**
 642          * Checks if the number of active workers exceeds the given limits
 643          *
 644          * @return bool Are there too much workers running?
 645          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 646          */
 647         private static function tooMuchWorkers(): bool
 648         {
 649                 $queues = DI::config()->get('system', 'worker_queues', 10);
 650
 651                 $maxqueues = $queues;
 652
 653                 $active = self::activeWorkers();
 654
 655                 // Decrease the number of workers at higher load
 656                 $load = System::currentLoad();
 657                 if ($load) {
 658                         $maxsysload = intval(DI::config()->get('system', 'maxloadavg', 20));
 659
 660                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 661                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 662                          * For some environments, this rapid decrease is not needed.
 663                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 664                          */
 665                         $exponent = intval(DI::config()->get('system', 'worker_load_exponent', 3));
 666                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 667                         $queues = intval(ceil($slope * $maxqueues));
 668
 669                         $processlist = '';
 670
 671                         if (DI::config()->get('system', 'worker_jpm')) {
 672                                 $intervals = explode(',', DI::config()->get('system', 'worker_jpm_range'));
 673                                 $jobs_per_minute = [];
 674                                 foreach ($intervals as $interval) {
 675                                         if ($interval == 0) {
 676                                                 continue;
 677                                         } else {
 678                                                 $interval = (int)$interval;
 679                                         }
 680
 681                                         $stamp = (float)microtime(true);
 682                                         $jobs = DBA::count('workerqueue', ["`done` AND `executed` > ?", DateTimeFormat::utc('now - ' . $interval . ' minute')]);
 683                                         self::$db_duration += (microtime(true) - $stamp);
 684                                         self::$db_duration_stat += (microtime(true) - $stamp);
 685                                         $jobs_per_minute[$interval] = number_format($jobs / $interval, 0);
 686                                 }
 687                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 688                         }
 689
 690                         // Create a list of queue entries grouped by their priority
 691                         $listitem = [0 => ''];
 692
 693                         $idle_workers = $active;
 694
 695                         $deferred = self::deferredEntries();
 696
 697                         if (DI::config()->get('system', 'worker_debug')) {
 698                                 $waiting_processes = 0;
 699                                 // Now adding all processes with workerqueue entries
 700                                 $stamp = (float)microtime(true);
 701                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 702                                 self::$db_duration += (microtime(true) - $stamp);
 703                                 self::$db_duration_stat += (microtime(true) - $stamp);
 704                                 while ($entry = DBA::fetch($jobs)) {
 705                                         $stamp = (float)microtime(true);
 706                                         $running = DBA::count('workerqueue-view', ['priority' => $entry['priority']]);
 707                                         self::$db_duration += (microtime(true) - $stamp);
 708                                         self::$db_duration_stat += (microtime(true) - $stamp);
 709                                         $idle_workers -= $running;
 710                                         $waiting_processes += $entry['entries'];
 711                                         $listitem[$entry['priority']] = $entry['priority'] . ':' . $running . '/' . $entry['entries'];
 712                                 }
 713                                 DBA::close($jobs);
 714                         } else {
 715                                 $waiting_processes =  self::totalEntries();
 716                                 $stamp = (float)microtime(true);
 717                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority` ORDER BY `priority`");
 718                                 self::$db_duration += (microtime(true) - $stamp);
 719                                 self::$db_duration_stat += (microtime(true) - $stamp);
 720
 721                                 while ($entry = DBA::fetch($jobs)) {
 722                                         $idle_workers -= $entry['running'];
 723                                         $listitem[$entry['priority']] = $entry['priority'] . ':' . $entry['running'];
 724                                 }
 725                                 DBA::close($jobs);
 726                         }
 727
 728                         $waiting_processes -= $deferred;
 729
 730                         $listitem[0] = '0:' . max(0, $idle_workers);
 731
 732                         $processlist .= ' ('.implode(', ', $listitem).')';
 733
 734                         if (DI::config()->get('system', 'worker_fastlane', false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 735                                 $top_priority = self::highestPriority();
 736                                 $high_running = self::processWithPriorityActive($top_priority);
 737
 738                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 739                                         Logger::info('Jobs with a higher priority are waiting but none is executed. Open a fastlane.', ['priority' => $top_priority]);
 740                                         $queues = $active + 1;
 741                                 }
 742                         }
 743
 744                         Logger::notice('Load: ' . $load . '/' . $maxsysload . ' - processes: ' . $deferred . '/' . $active . '/' . $waiting_processes . $processlist . ' - maximum: ' . $queues . '/' . $maxqueues);
 745
 746                         // Are there fewer workers running as possible? Then fork a new one.
 747                         if (!DI::config()->get('system', 'worker_dont_fork', false) && ($queues > ($active + 1)) && self::entriesExists()) {
 748                                 Logger::info('There are fewer workers as possible, fork a new worker.', ['active' => $active, 'queues' => $queues]);
 749                                 if (Worker\Daemon::isMode()) {
 750                                         Worker\IPC::SetJobState(true);
 751                                 } else {
 752                                         self::spawnWorker();
 753                                 }
 754                         }
 755                 }
 756
 757                 // if there are too much worker, we don't spawn a new one.
 758                 if (Worker\Daemon::isMode() && ($active > $queues)) {
 759                         Worker\IPC::SetJobState(false);
 760                 }
 761
 762                 return $active > $queues;
 763         }
 764
 765         /**
 766          * Returns the number of active worker processes
 767          *
 768          * @return integer Number of active worker processes
 769          * @throws \Exception
 770          */
 771         private static function activeWorkers(): int
 772         {
 773                 $stamp = (float)microtime(true);
 774                 $count = DI::process()->countCommand('Worker.php');
 775                 self::$db_duration += (microtime(true) - $stamp);
 776                 self::$db_duration_count += (microtime(true) - $stamp);
 777                 return $count;
 778         }
 779
 780         /**
 781          * Returns the number of active worker processes
 782          *
 783          * @return array List of worker process ids
 784          * @throws \Exception
 785          */
 786         private static function getWorkerPIDList(): array
 787         {
 788                 $ids = [];
 789                 $stamp = (float)microtime(true);
 790
 791                 $queues = DBA::p("SELECT `process`.`pid`, COUNT(`workerqueue`.`pid`) AS `entries` FROM `process`
 792                         LEFT JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `workerqueue`.`done`
 793                         GROUP BY `process`.`pid`");
 794                 while ($queue = DBA::fetch($queues)) {
 795                         $ids[$queue['pid']] = $queue['entries'];
 796                 }
 797                 DBA::close($queues);
 798
 799                 self::$db_duration += (microtime(true) - $stamp);
 800                 self::$db_duration_count += (microtime(true) - $stamp);
 801                 return $ids;
 802         }
 803
 804         /**
 805          * Returns waiting jobs for the current process id
 806          *
 807          * @return array|bool waiting workerqueue jobs or FALSE on failture
 808          * @throws \Exception
 809          */
 810         private static function getWaitingJobForPID()
 811         {
 812                 $stamp = (float)microtime(true);
 813                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 814                 self::$db_duration += (microtime(true) - $stamp);
 815                 if (DBA::isResult($r)) {
 816                         return DBA::toArray($r);
 817                 }
 818                 DBA::close($r);
 819
 820                 return false;
 821         }
 822
 823         /**
 824          * Returns the next jobs that should be executed
 825          * @param int $limit
 826          * @return array array with next jobs
 827          * @throws \Exception
 828          */
 829         private static function nextProcess(int $limit): array
 830         {
 831                 $priority = self::nextPriority();
 832                 if (empty($priority)) {
 833                         Logger::info('No tasks found');
 834                         return [];
 835                 }
 836
 837                 $ids = [];
 838                 $stamp = (float)microtime(true);
 839                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 840                 $tasks = DBA::select('workerqueue', ['id', 'command', 'parameter'], $condition, ['limit' => $limit, 'order' => ['retrial', 'created']]);
 841                 self::$db_duration += (microtime(true) - $stamp);
 842                 while ($task = DBA::fetch($tasks)) {
 843                         $ids[] = $task['id'];
 844                         // Only continue that loop while we are storing commands that can be processed quickly
 845                         if (!empty($task['command'])) {
 846                                 $command = $task['command'];
 847                         } else {
 848                                 $command = json_decode($task['parameter'])[0];
 849                         }
 850
 851                         if (!in_array($command, self::FAST_COMMANDS)) {
 852                                 break;
 853                         }
 854                 }
 855                 DBA::close($tasks);
 856
 857                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
 858                 return $ids;
 859         }
 860
 861         /**
 862          * Returns the priority of the next workerqueue job
 863          *
 864          * @return string|bool priority or FALSE on failure
 865          * @throws \Exception
 866          */
 867         private static function nextPriority()
 868         {
 869                 $waiting = [];
 870                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
 871                 foreach ($priorities as $priority) {
 872                         $stamp = (float)microtime(true);
 873                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 874                                 $waiting[$priority] = true;
 875                         }
 876                         self::$db_duration += (microtime(true) - $stamp);
 877                 }
 878
 879                 if (!empty($waiting[PRIORITY_CRITICAL])) {
 880                         return PRIORITY_CRITICAL;
 881                 }
 882
 883                 $running = [];
 884                 $running_total = 0;
 885                 $stamp = (float)microtime(true);
 886                 $processes = DBA::p("SELECT COUNT(DISTINCT(`pid`)) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority`");
 887                 self::$db_duration += (microtime(true) - $stamp);
 888                 while ($process = DBA::fetch($processes)) {
 889                         $running[$process['priority']] = $process['running'];
 890                         $running_total += $process['running'];
 891                 }
 892                 DBA::close($processes);
 893
 894                 foreach ($priorities as $priority) {
 895                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 896                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 897                                 return $priority;
 898                         }
 899                 }
 900
 901                 $active = max(self::activeWorkers(), $running_total);
 902                 $priorities = max(count($waiting), count($running));
 903                 $exponent = 2;
 904
 905                 $total = 0;
 906                 for ($i = 1; $i <= $priorities; ++$i) {
 907                         $total += pow($i, $exponent);
 908                 }
 909
 910                 $limit = [];
 911                 for ($i = 1; $i <= $priorities; ++$i) {
 912                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 913                 }
 914
 915                 $i = 0;
 916                 foreach ($running as $priority => $workers) {
 917                         if ($workers < $limit[$i++]) {
 918                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 919                                 return $priority;
 920                         }
 921                 }
 922
 923                 if (!empty($waiting)) {
 924                         $priority = array_keys($waiting)[0];
 925                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
 926                         return $priority;
 927                 }
 928
 929                 return false;
 930         }
 931
 932         /**
 933          * Find and claim the next worker process for us
 934          *
 935          * @return void
 936          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 937          */
 938         private static function findWorkerProcesses()
 939         {
 940                 $fetch_limit = DI::config()->get('system', 'worker_fetch_limit', 1);
 941
 942                 if (DI::config()->get('system', 'worker_multiple_fetch')) {
 943                         $pids = [];
 944                         foreach (self::getWorkerPIDList() as $pid => $count) {
 945                                 if ($count <= $fetch_limit) {
 946                                         $pids[] = $pid;
 947                                 }
 948                         }
 949                         if (empty($pids)) {
 950                                 return;
 951                         }
 952                         $limit = $fetch_limit * count($pids);
 953                 } else {
 954                         $pids = [getmypid()];
 955                         $limit = $fetch_limit;
 956                 }
 957
 958                 $ids = self::nextProcess($limit);
 959                 $limit -= count($ids);
 960
 961                 // If there is not enough results we check without priority limit
 962                 if ($limit > 0) {
 963                         $stamp = (float)microtime(true);
 964                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 965                         $tasks = DBA::select('workerqueue', ['id', 'command', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'retrial', 'created']]);
 966                         self::$db_duration += (microtime(true) - $stamp);
 967
 968                         while ($task = DBA::fetch($tasks)) {
 969                                 $ids[] = $task['id'];
 970                                 // Only continue that loop while we are storing commands that can be processed quickly
 971                                 if (!empty($task['command'])) {
 972                                         $command = $task['command'];
 973                                 } else {
 974                                         $command = json_decode($task['parameter'])[0];
 975                                 }
 976                                 if (!in_array($command, self::FAST_COMMANDS)) {
 977                                         break;
 978                                 }
 979                         }
 980                         DBA::close($tasks);
 981                 }
 982
 983                 if (empty($ids)) {
 984                         return;
 985                 }
 986
 987                 // Assign the task ids to the workers
 988                 $worker = [];
 989                 foreach (array_unique($ids) as $id) {
 990                         $pid = next($pids);
 991                         if (!$pid) {
 992                                 $pid = reset($pids);
 993                         }
 994                         $worker[$pid][] = $id;
 995                 }
 996
 997                 $stamp = (float)microtime(true);
 998                 foreach ($worker as $worker_pid => $worker_ids) {
 999                         Logger::info('Set queue entry', ['pid' => $worker_pid, 'ids' => $worker_ids]);
1000                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $worker_pid],
1001                                 ['id' => $worker_ids, 'done' => false, 'pid' => 0]);
1002                 }
1003                 self::$db_duration += (microtime(true) - $stamp);
1004                 self::$db_duration_write += (microtime(true) - $stamp);
1005         }
1006
1007         /**
1008          * Returns the next worker process
1009          *
1010          * @return array worker processes
1011          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1012          */
1013         public static function workerProcess(): array
1014         {
1015                 // There can already be jobs for us in the queue.
1016                 $waiting = self::getWaitingJobForPID();
1017                 if (!empty($waiting)) {
1018                         return $waiting;
1019                 }
1020
1021                 $stamp = (float)microtime(true);
1022                 if (!DI::lock()->acquire(self::LOCK_PROCESS)) {
1023                         return [];
1024                 }
1025                 self::$lock_duration += (microtime(true) - $stamp);
1026
1027                 self::findWorkerProcesses();
1028
1029                 DI::lock()->release(self::LOCK_PROCESS);
1030
1031                 // Prevents "Return value of Friendica\Core\Worker::workerProcess() must be of the type array, bool returned"
1032                 $process = self::getWaitingJobForPID();
1033                 return (is_array($process) ? $process : []);
1034         }
1035
1036         /**
1037          * Removes a workerqueue entry from the current process
1038          *
1039          * @param Process $process the process behind the workerqueue
1040          *
1041          * @return void
1042          * @throws \Exception
1043          */
1044         public static function unclaimProcess(Process $process)
1045         {
1046                 $stamp = (float)microtime(true);
1047                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $process->pid, 'done' => false]);
1048                 self::$db_duration += (microtime(true) - $stamp);
1049                 self::$db_duration_write += (microtime(true) - $stamp);
1050         }
1051
1052         /**
1053          * Fork a child process
1054          *
1055          * @param boolean $do_cron
1056          * @return void
1057          */
1058         private static function forkProcess(bool $do_cron)
1059         {
1060                 if (DI::system()->isMinMemoryReached()) {
1061                         Logger::warning('Memory limit reached - quitting');
1062                         return;
1063                 }
1064
1065                 // Children inherit their parent's database connection.
1066                 // To avoid problems we disconnect and connect both parent and child
1067                 DBA::disconnect();
1068                 $pid = pcntl_fork();
1069                 if ($pid == -1) {
1070                         DBA::connect();
1071                         Logger::warning('Could not spawn worker');
1072                         return;
1073                 } elseif ($pid) {
1074                         // The parent process continues here
1075                         DBA::connect();
1076
1077                         Worker\IPC::SetJobState(true, $pid);
1078                         Logger::info('Spawned new worker', ['pid' => $pid]);
1079
1080                         $cycles = 0;
1081                         while (Worker\IPC::JobsExists($pid) && (++$cycles < 100)) {
1082                                 usleep(10000);
1083                         }
1084
1085                         Logger::info('Spawned worker is ready', ['pid' => $pid, 'wait_cycles' => $cycles]);
1086                         return;
1087                 }
1088
1089                 // We now are in the new worker
1090                 DBA::connect();
1091
1092                 DI::flushLogger();
1093                 $process = DI::process()->create(getmypid(), basename(__FILE__));
1094
1095                 $cycles = 0;
1096                 while (!Worker\IPC::JobsExists($process->pid) && (++$cycles < 100)) {
1097                         usleep(10000);
1098                 }
1099
1100                 Logger::info('Worker spawned', ['pid' => $process->pid, 'wait_cycles' => $cycles]);
1101
1102                 self::processQueue($do_cron, $process);
1103
1104                 self::unclaimProcess($process);
1105
1106                 Worker\IPC::SetJobState(false, $process->pid);
1107                 DI::process()->delete($process);
1108                 Logger::info('Worker ended', ['pid' => $process->pid]);
1109                 exit();
1110         }
1111
1112         /**
1113          * Spawns a new worker
1114          *
1115          * @param bool $do_cron
1116          * @return void
1117          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1118          */
1119         public static function spawnWorker(bool $do_cron = false)
1120         {
1121                 if (Worker\Daemon::isMode() && DI::config()->get('system', 'worker_fork')) {
1122                         self::forkProcess($do_cron);
1123                 } else {
1124                         DI::system()->run('bin/worker.php', ['no_cron' => !$do_cron]);
1125                 }
1126                 if (Worker\Daemon::isMode()) {
1127                         Worker\IPC::SetJobState(false);
1128                 }
1129         }
1130
1131         /**
1132          * Adds tasks to the worker queue
1133          *
1134          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1135          *
1136          * next args are passed as $cmd command line
1137          * or: Worker::add(PRIORITY_HIGH, 'Notifier', Delivery::DELETION, $drop_id);
1138          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), 'Delivery', $post_id);
1139          *
1140          * @return int '0' if worker queue entry already existed or there had been an error, otherwise the ID of the worker task
1141          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1142          * @note $cmd and string args are surrounded with ''
1143          *
1144          * @hooks 'proc_run'
1145          *    array $arr
1146          *
1147          */
1148         public static function add(...$args)
1149         {
1150                 if (!count($args)) {
1151                         return 0;
1152                 }
1153
1154                 $arr = ['args' => $args, 'run_cmd' => true];
1155
1156                 Hook::callAll('proc_run', $arr);
1157                 if (!$arr['run_cmd'] || !count($args)) {
1158                         return 1;
1159                 }
1160
1161                 $priority = PRIORITY_MEDIUM;
1162                 // Don't fork from frontend tasks by default
1163                 $dont_fork = DI::config()->get('system', 'worker_dont_fork', false) || !DI::mode()->isBackend();
1164                 $created = DateTimeFormat::utcNow();
1165                 $delayed = DBA::NULL_DATETIME;
1166                 $force_priority = false;
1167
1168                 $run_parameter = array_shift($args);
1169
1170                 if (is_int($run_parameter)) {
1171                         $priority = $run_parameter;
1172                 } elseif (is_array($run_parameter)) {
1173                         if (isset($run_parameter['delayed'])) {
1174                                 $delayed = $run_parameter['delayed'];
1175                         }
1176                         if (isset($run_parameter['priority'])) {
1177                                 $priority = $run_parameter['priority'];
1178                         }
1179                         if (isset($run_parameter['created'])) {
1180                                 $created = $run_parameter['created'];
1181                         }
1182                         if (isset($run_parameter['dont_fork'])) {
1183                                 $dont_fork = $run_parameter['dont_fork'];
1184                         }
1185                         if (isset($run_parameter['force_priority'])) {
1186                                 $force_priority = $run_parameter['force_priority'];
1187                         }
1188                 } else {
1189                         throw new \InvalidArgumentException('Priority number or task parameter array expected as first argument');
1190                 }
1191
1192                 $command = array_shift($args);
1193                 $parameters = json_encode($args);
1194                 $found = DBA::exists('workerqueue', ['command' => $command, 'parameter' => $parameters, 'done' => false]);
1195                 $added = 0;
1196
1197                 if (!is_int($priority) || !in_array($priority, PRIORITIES)) {
1198                         Logger::warning('Invalid priority', ['priority' => $priority, 'command' => $command, 'callstack' => System::callstack(20)]);
1199                         $priority = PRIORITY_MEDIUM;
1200                 }
1201
1202                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1203                 if (DBA::errorNo() != 0) {
1204                         return 0;
1205                 }
1206
1207                 if (!$found) {
1208                         if (!DBA::insert('workerqueue', ['command' => $command, 'parameter' => $parameters, 'created' => $created,
1209                                 'priority' => $priority, 'next_try' => $delayed])) {
1210                                 return 0;
1211                         }
1212                         $added = DBA::lastInsertId();
1213                 } elseif ($force_priority) {
1214                         DBA::update('workerqueue', ['priority' => $priority], ['command' => $command, 'parameter' => $parameters, 'done' => false, 'pid' => 0]);
1215                 }
1216
1217                 // Set the IPC flag to ensure an immediate process execution via daemon
1218                 if (Worker\Daemon::isMode()) {
1219                         Worker\IPC::SetJobState(true);
1220                 }
1221
1222                 Worker\Daemon::checkState();
1223
1224                 // Should we quit and wait for the worker to be called as a cronjob?
1225                 if ($dont_fork) {
1226                         return $added;
1227                 }
1228
1229                 // If there is a lock then we don't have to check for too much worker
1230                 if (!DI::lock()->acquire(self::LOCK_WORKER, 0)) {
1231                         return $added;
1232                 }
1233
1234                 // If there are already enough workers running, don't fork another one
1235                 $quit = self::tooMuchWorkers();
1236                 DI::lock()->release(self::LOCK_WORKER);
1237
1238                 if ($quit) {
1239                         return $added;
1240                 }
1241
1242                 // Quit on daemon mode
1243                 if (Worker\Daemon::isMode()) {
1244                         return $added;
1245                 }
1246
1247                 // Now call the worker to execute the jobs that we just added to the queue
1248                 self::spawnWorker();
1249
1250                 return $added;
1251         }
1252
1253         public static function countWorkersByCommand(string $command): int
1254         {
1255                 return DBA::count('workerqueue', ['done' => false, 'pid' => 0, 'command' => $command]);
1256         }
1257
1258         /**
1259          * Returns the next retrial level for worker jobs.
1260          * This function will skip levels when jobs are older.
1261          *
1262          * @param array $queue Worker queue entry
1263          * @param integer $max_level maximum retrial level
1264          * @return integer the next retrial level value
1265          */
1266         private static function getNextRetrial(array $queue, int $max_level): int
1267         {
1268                 $created = strtotime($queue['created']);
1269                 $retrial_time = time() - $created;
1270
1271                 $new_retrial = $queue['retrial'] + 1;
1272                 $total = 0;
1273                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1274                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1275                         $total += $delay;
1276                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1277                                 $new_retrial = $retrial;
1278                         }
1279                 }
1280                 Logger::notice('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1281                 return $new_retrial;
1282         }
1283
1284         /**
1285          * Defers the current worker entry
1286          *
1287          * @return boolean had the entry been deferred?
1288          * @throws \Exception
1289          */
1290         public static function defer(): bool
1291         {
1292                 $queue = DI::app()->getQueue();
1293
1294                 if (empty($queue)) {
1295                         return false;
1296                 }
1297
1298                 $id = $queue['id'];
1299                 $priority = $queue['priority'];
1300
1301                 $max_level = DI::config()->get('system', 'worker_defer_limit');
1302
1303                 $new_retrial = self::getNextRetrial($queue, $max_level);
1304
1305                 if ($new_retrial > $max_level) {
1306                         Logger::notice('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]);
1307                         return false;
1308                 }
1309
1310                 // Calculate the delay until the next trial
1311                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1312                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1313
1314                 if (($priority < PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1315                         $priority = PRIORITY_MEDIUM;
1316                 } elseif (($priority < PRIORITY_LOW) && ($new_retrial > 6)) {
1317                         $priority = PRIORITY_LOW;
1318                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1319                         $priority = PRIORITY_NEGLIGIBLE;
1320                 }
1321
1322                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1323
1324                 $stamp = (float)microtime(true);
1325                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1326                 DBA::update('workerqueue', $fields, ['id' => $id]);
1327                 self::$db_duration += (microtime(true) - $stamp);
1328                 self::$db_duration_write += (microtime(true) - $stamp);
1329
1330                 return true;
1331         }
1332
1333         /**
1334          * Check if the system is inside the defined maintenance window
1335          *
1336          * @param bool $check_last_execution Whether check last execution
1337          * @return boolean
1338          */
1339         public static function isInMaintenanceWindow(bool $check_last_execution = false): bool
1340         {
1341                 // Calculate the seconds of the start end end of the maintenance window
1342                 $start = strtotime(DI::config()->get('system', 'maintenance_start')) % 86400;
1343                 $end = strtotime(DI::config()->get('system', 'maintenance_end')) % 86400;
1344
1345                 Logger::info('Maintenance window', ['start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1346
1347                 if ($check_last_execution) {
1348                         // Calculate the window duration
1349                         $duration = max($start, $end) - min($start, $end);
1350
1351                         // Quit when the last cron execution had been after the previous window
1352                         $last_cron = DI::config()->get('system', 'last_cron_daily');
1353                         if ($last_cron + $duration > time()) {
1354                                 Logger::info('The Daily cron had been executed recently', ['last' => date(DateTimeFormat::MYSQL, $last_cron), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1355                                 return false;
1356                         }
1357                 }
1358
1359                 $current = time() % 86400;
1360
1361                 if ($start < $end) {
1362                         // Execute if we are inside the window
1363                         $execute = ($current >= $start) && ($current <= $end);
1364                 } else {
1365                         // Don't execute if we are outside the window
1366                         $execute = !(($current > $end) && ($current < $start));
1367                 }
1368
1369                 if ($execute) {
1370                         Logger::info('We are inside the maintenance window', ['current' => date('H:i:s', $current), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1371                 } else {
1372                         Logger::info('We are outside the maintenance window', ['current' => date('H:i:s', $current), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1373                 }
1374
1375                 return $execute;
1376         }
1377 }