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