src/Core/Worker.php

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