src/Core/Worker.php

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