src/Core/Worker.php

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