src/Core/Worker.php

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