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