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