src/Core/Worker.php

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