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