src/Core/Worker.php

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