src/Core/Worker.php

   1 <?php
   2 /**
   3  * @file src/Core/Worker.php
   4  */
   5 namespace Friendica\Core;
   6
   7 use Friendica\Core\Addon;
   8 use Friendica\Core\Config;
   9 use Friendica\Core\System;
  10 use Friendica\Database\DBM;
  11 use Friendica\Model\Process;
  12 use Friendica\Util\Lock;
  13 use Friendica\Util\Network;
  14 use Friendica\Util\Temporal;
  15
  16 use dba;
  17
  18 require_once 'include/dba.php';
  19
  20 /**
  21  * @file src/Core/Worker.php
  22  *
  23  * @brief Contains the class for the worker background job processing
  24  */
  25
  26 /**
  27  * @brief Worker methods
  28  */
  29 class Worker
  30 {
  31         private static $up_start;
  32         private static $db_duration;
  33         private static $last_update;
  34         private static $lock_duration;
  35
  36         /**
  37          * @brief Processes the tasks that are in the workerqueue table
  38          *
  39          * @param boolean $run_cron Should the cron processes be executed?
  40          * @return void
  41          */
  42         public static function processQueue($run_cron = true)
  43         {
  44                 $a = get_app();
  45
  46                 self::$up_start = microtime(true);
  47
  48                 // At first check the maximum load. We shouldn't continue with a high load
  49                 if ($a->maxload_reached()) {
  50                         logger('Pre check: maximum load reached, quitting.', LOGGER_DEBUG);
  51                         return;
  52                 }
  53
  54                 // We now start the process. This is done after the load check since this could increase the load.
  55                 self::startProcess();
  56
  57                 // Kill stale processes every 5 minutes
  58                 $last_cleanup = Config::get('system', 'poller_last_cleaned', 0);
  59                 if (time() > ($last_cleanup + 300)) {
  60                         Config::set('system', 'poller_last_cleaned', time());
  61                         self::killStaleWorkers();
  62                 }
  63
  64                 // Count active workers and compare them with a maximum value that depends on the load
  65                 if (self::tooMuchWorkers()) {
  66                         logger('Pre check: Active worker limit reached, quitting.', LOGGER_DEBUG);
  67                         return;
  68                 }
  69
  70                 // Do we have too few memory?
  71                 if ($a->min_memory_reached()) {
  72                         logger('Pre check: Memory limit reached, quitting.', LOGGER_DEBUG);
  73                         return;
  74                 }
  75
  76                 // Possibly there are too much database connections
  77                 if (self::maxConnectionsReached()) {
  78                         logger('Pre check: maximum connections reached, quitting.', LOGGER_DEBUG);
  79                         return;
  80                 }
  81
  82                 // Possibly there are too much database processes that block the system
  83                 if ($a->max_processes_reached()) {
  84                         logger('Pre check: maximum processes reached, quitting.', LOGGER_DEBUG);
  85                         return;
  86                 }
  87
  88                 // Now we start additional cron processes if we should do so
  89                 if ($run_cron) {
  90                         self::runCron();
  91                 }
  92
  93                 $starttime = time();
  94
  95                 // We fetch the next queue entry that is about to be executed
  96                 while ($r = self::workerProcess($passing_slow)) {
  97                         // When we are processing jobs with a lower priority, we don't refetch new jobs
  98                         // Otherwise fast jobs could wait behind slow ones and could be blocked.
  99                         $refetched = $passing_slow;
 100
 101                         foreach ($r as $entry) {
 102                                 // Assure that the priority is an integer value
 103                                 $entry['priority'] = (int)$entry['priority'];
 104
 105                                 // The work will be done
 106                                 if (!self::execute($entry)) {
 107                                         logger('Process execution failed, quitting.', LOGGER_DEBUG);
 108                                         return;
 109                                 }
 110
 111                                 // If possible we will fetch new jobs for this worker
 112                                 if (!$refetched && Lock::set('poller_worker_process', 0)) {
 113                                         $stamp = (float)microtime(true);
 114                                         $refetched = self::findWorkerProcesses($passing_slow);
 115                                         self::$db_duration += (microtime(true) - $stamp);
 116                                         Lock::remove('poller_worker_process');
 117                                 }
 118                         }
 119
 120                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 121                         if (Lock::set('poller_worker', 0)) {
 122                                 $stamp = (float)microtime(true);
 123                                 // Count active workers and compare them with a maximum value that depends on the load
 124                                 if (self::tooMuchWorkers()) {
 125                                         logger('Active worker limit reached, quitting.', LOGGER_DEBUG);
 126                                         return;
 127                                 }
 128
 129                                 // Check free memory
 130                                 if ($a->min_memory_reached()) {
 131                                         logger('Memory limit reached, quitting.', LOGGER_DEBUG);
 132                                         return;
 133                                 }
 134                                 Lock::remove('poller_worker');
 135                                 self::$db_duration += (microtime(true) - $stamp);
 136                         }
 137
 138                         // Quit the worker once every 5 minutes
 139                         if (time() > ($starttime + 300)) {
 140                                 logger('Process lifetime reached, quitting.', LOGGER_DEBUG);
 141                                 return;
 142                         }
 143                 }
 144                 logger("Couldn't select a workerqueue entry, quitting.", LOGGER_DEBUG);
 145         }
 146
 147         /**
 148          * @brief Returns the number of non executed entries in the worker queue
 149          *
 150          * @return integer Number of non executed entries in the worker queue
 151          */
 152         private static function totalEntries()
 153         {
 154                 $s = dba::fetch_first("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` <= ? AND NOT `done`", NULL_DATE);
 155                 if (DBM::is_result($s)) {
 156                         return $s["total"];
 157                 } else {
 158                         return 0;
 159                 }
 160         }
 161
 162         /**
 163          * @brief Returns the highest priority in the worker queue that isn't executed
 164          *
 165          * @return integer Number of active worker processes
 166          */
 167         private static function highestPriority()
 168         {
 169                 $condition = ["`executed` <= ? AND NOT `done`", NULL_DATE];
 170                 $workerqueue = dba::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 171                 if (DBM::is_result($workerqueue)) {
 172                         return $workerqueue["priority"];
 173                 } else {
 174                         return 0;
 175                 }
 176         }
 177
 178         /**
 179          * @brief Returns if a process with the given priority is running
 180          *
 181          * @param integer $priority The priority that should be checked
 182          *
 183          * @return integer Is there a process running with that priority?
 184          */
 185         private static function processWithPriorityActive($priority)
 186         {
 187                 $condition = ["`priority` <= ? AND `executed` > ? AND NOT `done`", $priority, NULL_DATE];
 188                 return dba::exists('workerqueue', $condition);
 189         }
 190
 191         /**
 192          * @brief Execute a worker entry
 193          *
 194          * @param array $queue Workerqueue entry
 195          *
 196          * @return boolean "true" if further processing should be stopped
 197          */
 198         public static function execute($queue)
 199         {
 200                 $a = get_app();
 201
 202                 $mypid = getmypid();
 203
 204                 // Quit when in maintenance
 205                 if (Config::get('system', 'maintenance', true)) {
 206                         logger("Maintenance mode - quit process ".$mypid, LOGGER_DEBUG);
 207                         return false;
 208                 }
 209
 210                 // Constantly check the number of parallel database processes
 211                 if ($a->max_processes_reached()) {
 212                         logger("Max processes reached for process ".$mypid, LOGGER_DEBUG);
 213                         return false;
 214                 }
 215
 216                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 217                 if (self::maxConnectionsReached()) {
 218                         logger("Max connection reached for process ".$mypid, LOGGER_DEBUG);
 219                         return false;
 220                 }
 221
 222                 $argv = json_decode($queue["parameter"]);
 223
 224                 // Check for existance and validity of the include file
 225                 $include = $argv[0];
 226
 227                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 228                         // We constantly update the "executed" date every minute to avoid being killed too soon
 229                         if (!isset(self::$last_update)) {
 230                                 self::$last_update = strtotime($queue["executed"]);
 231                         }
 232
 233                         $age = (time() - self::$last_update) / 60;
 234                         self::$last_update = time();
 235
 236                         if ($age > 1) {
 237                                 $stamp = (float)microtime(true);
 238                                 dba::update('workerqueue', ['executed' => Temporal::utcNow()], ['pid' => $mypid, 'done' => false]);
 239                                 self::$db_duration += (microtime(true) - $stamp);
 240                         }
 241
 242                         array_shift($argv);
 243
 244                         self::execFunction($queue, $include, $argv, true);
 245
 246                         $stamp = (float)microtime(true);
 247                         if (dba::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 248                                 Config::set('system', 'last_poller_execution', Temporal::utcNow());
 249                         }
 250                         self::$db_duration = (microtime(true) - $stamp);
 251
 252                         return true;
 253                 }
 254
 255                 // The script could be provided as full path or only with the function name
 256                 if ($include == basename($include)) {
 257                         $include = "include/".$include.".php";
 258                 }
 259
 260                 if (!validate_include($include)) {
 261                         logger("Include file ".$argv[0]." is not valid!");
 262                         dba::delete('workerqueue', ['id' => $queue["id"]]);
 263                         return true;
 264                 }
 265
 266                 require_once $include;
 267
 268                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 269
 270                 if (function_exists($funcname)) {
 271                         // We constantly update the "executed" date every minute to avoid being killed too soon
 272                         if (!isset(self::$last_update)) {
 273                                 self::$last_update = strtotime($queue["executed"]);
 274                         }
 275
 276                         $age = (time() - self::$last_update) / 60;
 277                         self::$last_update = time();
 278
 279                         if ($age > 1) {
 280                                 $stamp = (float)microtime(true);
 281                                 dba::update('workerqueue', ['executed' => Temporal::utcNow()], ['pid' => $mypid, 'done' => false]);
 282                                 self::$db_duration += (microtime(true) - $stamp);
 283                         }
 284
 285                         self::execFunction($queue, $funcname, $argv, false);
 286
 287                         $stamp = (float)microtime(true);
 288                         if (dba::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 289                                 Config::set('system', 'last_poller_execution', Temporal::utcNow());
 290                         }
 291                         self::$db_duration = (microtime(true) - $stamp);
 292                 } else {
 293                         logger("Function ".$funcname." does not exist");
 294                         dba::delete('workerqueue', ['id' => $queue["id"]]);
 295                 }
 296
 297                 return true;
 298         }
 299
 300         /**
 301          * @brief Execute a function from the queue
 302          *
 303          * @param array   $queue       Workerqueue entry
 304          * @param string  $funcname    name of the function
 305          * @param array   $argv        Array of values to be passed to the function
 306          * @param boolean $method_call boolean
 307          * @return void
 308          */
 309         private static function execFunction($queue, $funcname, $argv, $method_call)
 310         {
 311                 $a = get_app();
 312
 313                 $mypid = getmypid();
 314
 315                 $argc = count($argv);
 316
 317                 $new_process_id = uniqid("wrk", true);
 318
 319                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
 320
 321                 $stamp = (float)microtime(true);
 322
 323                 // We use the callstack here to analyze the performance of executed worker entries.
 324                 // For this reason the variables have to be initialized.
 325                 if (Config::get("system", "profiler")) {
 326                         $a->performance["start"] = microtime(true);
 327                         $a->performance["database"] = 0;
 328                         $a->performance["database_write"] = 0;
 329                         $a->performance["network"] = 0;
 330                         $a->performance["file"] = 0;
 331                         $a->performance["rendering"] = 0;
 332                         $a->performance["parser"] = 0;
 333                         $a->performance["marktime"] = 0;
 334                         $a->performance["markstart"] = microtime(true);
 335                         $a->callstack = [];
 336                 }
 337
 338                 // For better logging create a new process id for every worker call
 339                 // But preserve the old one for the worker
 340                 $old_process_id = $a->process_id;
 341                 $a->process_id = $new_process_id;
 342                 $a->queue = $queue;
 343
 344                 $up_duration = number_format(microtime(true) - self::$up_start, 3);
 345
 346                 // Reset global data to avoid interferences
 347                 unset($_SESSION);
 348
 349                 if ($method_call) {
 350                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 351                 } else {
 352                         $funcname($argv, $argc);
 353                 }
 354
 355                 $a->process_id = $old_process_id;
 356                 unset($a->queue);
 357
 358                 $duration = number_format(microtime(true) - $stamp, 3);
 359
 360                 self::$up_start = microtime(true);
 361
 362                 /* With these values we can analyze how effective the worker is.
 363                  * The database and rest time should be low since this is the unproductive time.
 364                  * The execution time is the productive time.
 365                  * By changing parameters like the maximum number of workers we can check the effectivness.
 366                 */
 367                 logger(
 368                         'DB: '.number_format(self::$db_duration, 2).
 369                         ' - Lock: '.number_format(self::$lock_duration, 2).
 370                         ' - Rest: '.number_format($up_duration - self::$db_duration - self::$lock_duration, 2).
 371                         ' - Execution: '.number_format($duration, 2),
 372                         LOGGER_DEBUG
 373                 );
 374
 375                 self::$lock_duration = 0;
 376
 377                 if ($duration > 3600) {
 378                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", LOGGER_DEBUG);
 379                 } elseif ($duration > 600) {
 380                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 381                 } elseif ($duration > 300) {
 382                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 383                 } elseif ($duration > 120) {
 384                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 385                 }
 386
 387                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds. Process PID: ".$new_process_id);
 388
 389                 // Write down the performance values into the log
 390                 if (Config::get("system", "profiler")) {
 391                         $duration = microtime(true)-$a->performance["start"];
 392
 393                         if (Config::get("rendertime", "callstack")) {
 394                                 if (isset($a->callstack["database"])) {
 395                                         $o = "\nDatabase Read:\n";
 396                                         foreach ($a->callstack["database"] as $func => $time) {
 397                                                 $time = round($time, 3);
 398                                                 if ($time > 0) {
 399                                                         $o .= $func.": ".$time."\n";
 400                                                 }
 401                                         }
 402                                 }
 403                                 if (isset($a->callstack["database_write"])) {
 404                                         $o .= "\nDatabase Write:\n";
 405                                         foreach ($a->callstack["database_write"] as $func => $time) {
 406                                                 $time = round($time, 3);
 407                                                 if ($time > 0) {
 408                                                         $o .= $func.": ".$time."\n";
 409                                                 }
 410                                         }
 411                                 }
 412                                 if (isset($a->callstack["network"])) {
 413                                         $o .= "\nNetwork:\n";
 414                                         foreach ($a->callstack["network"] as $func => $time) {
 415                                                 $time = round($time, 3);
 416                                                 if ($time > 0) {
 417                                                         $o .= $func.": ".$time."\n";
 418                                                 }
 419                                         }
 420                                 }
 421                         } else {
 422                                 $o = '';
 423                         }
 424
 425                         logger(
 426                                 "ID ".$queue["id"].": ".$funcname.": ".sprintf(
 427                                         "DB: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
 428                                         number_format($a->performance["database"] - $a->performance["database_write"], 2),
 429                                         number_format($a->performance["database_write"], 2),
 430                                         number_format($a->performance["network"], 2),
 431                                         number_format($a->performance["file"], 2),
 432                                         number_format($duration - ($a->performance["database"] + $a->performance["network"] + $a->performance["file"]), 2),
 433                                         number_format($duration, 2)
 434                                 ),
 435                                 LOGGER_DEBUG
 436                         );
 437                 }
 438
 439                 $cooldown = Config::get("system", "worker_cooldown", 0);
 440
 441                 if ($cooldown > 0) {
 442                         logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 443                         sleep($cooldown);
 444                 }
 445         }
 446
 447         /**
 448          * @brief Checks if the number of database connections has reached a critical limit.
 449          *
 450          * @return bool Are more than 3/4 of the maximum connections used?
 451          */
 452         private static function maxConnectionsReached()
 453         {
 454                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 455                 $max = Config::get("system", "max_connections");
 456
 457                 // Fetch the percentage level where the worker will get active
 458                 $maxlevel = Config::get("system", "max_connections_level", 75);
 459
 460                 if ($max == 0) {
 461                         // the maximum number of possible user connections can be a system variable
 462                         $r = dba::fetch_first("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 463                         if (DBM::is_result($r)) {
 464                                 $max = $r["Value"];
 465                         }
 466                         // Or it can be granted. This overrides the system variable
 467                         $r = dba::p('SHOW GRANTS');
 468                         while ($grants = dba::fetch($r)) {
 469                                 $grant = array_pop($grants);
 470                                 if (stristr($grant, "GRANT USAGE ON")) {
 471                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 472                                                 $max = $match[1];
 473                                         }
 474                                 }
 475                         }
 476                         dba::close($r);
 477                 }
 478
 479                 // If $max is set we will use the processlist to determine the current number of connections
 480                 // The processlist only shows entries of the current user
 481                 if ($max != 0) {
 482                         $r = dba::p('SHOW PROCESSLIST');
 483                         $used = dba::num_rows($r);
 484                         dba::close($r);
 485
 486                         logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 487
 488                         $level = ($used / $max) * 100;
 489
 490                         if ($level >= $maxlevel) {
 491                                 logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 492                                 return true;
 493                         }
 494                 }
 495
 496                 // We will now check for the system values.
 497                 // This limit could be reached although the user limits are fine.
 498                 $r = dba::fetch_first("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 499                 if (!DBM::is_result($r)) {
 500                         return false;
 501                 }
 502                 $max = intval($r["Value"]);
 503                 if ($max == 0) {
 504                         return false;
 505                 }
 506                 $r = dba::fetch_first("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 507                 if (!DBM::is_result($r)) {
 508                         return false;
 509                 }
 510                 $used = intval($r["Value"]);
 511                 if ($used == 0) {
 512                         return false;
 513                 }
 514                 logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 515
 516                 $level = $used / $max * 100;
 517
 518                 if ($level < $maxlevel) {
 519                         return false;
 520                 }
 521                 logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 522                 return true;
 523         }
 524
 525         /**
 526          * @brief fix the queue entry if the worker process died
 527          * @return void
 528          */
 529         private static function killStaleWorkers()
 530         {
 531                 $entries = dba::select(
 532                         'workerqueue',
 533                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 534                         ['`executed` > ? AND NOT `done` AND `pid` != 0', NULL_DATE],
 535                         ['order' => ['priority', 'created']]
 536                 );
 537
 538                 while ($entry = dba::fetch($entries)) {
 539                         if (!posix_kill($entry["pid"], 0)) {
 540                                 dba::update(
 541                                         'workerqueue',
 542                                         ['executed' => NULL_DATE, 'pid' => 0],
 543                                         ['id' => $entry["id"]]
 544                                 );
 545                         } else {
 546                                 // Kill long running processes
 547                                 // Check if the priority is in a valid range
 548                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 549                                         $entry["priority"] = PRIORITY_MEDIUM;
 550                                 }
 551
 552                                 // Define the maximum durations
 553                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 554                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 555
 556                                 $argv = json_decode($entry["parameter"]);
 557                                 $argv[0] = basename($argv[0]);
 558
 559                                 // How long is the process already running?
 560                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 561                                 if ($duration > $max_duration) {
 562                                         logger("Worker process ".$entry["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
 563                                         posix_kill($entry["pid"], SIGTERM);
 564
 565                                         // We killed the stale process.
 566                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 567                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 568                                         if ($entry["priority"] == PRIORITY_HIGH) {
 569                                                 $new_priority = PRIORITY_MEDIUM;
 570                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 571                                                 $new_priority = PRIORITY_LOW;
 572                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 573                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 574                                         }
 575                                         dba::update(
 576                                                 'workerqueue',
 577                                                 ['executed' => NULL_DATE, 'created' => Temporal::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 578                                                 ['id' => $entry["id"]]
 579                                         );
 580                                 } else {
 581                                         logger("Worker process ".$entry["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
 582                                 }
 583                         }
 584                 }
 585         }
 586
 587         /**
 588          * @brief Checks if the number of active workers exceeds the given limits
 589          *
 590          * @return bool Are there too much workers running?
 591          */
 592         public static function tooMuchWorkers()
 593         {
 594                 $queues = Config::get("system", "worker_queues", 4);
 595
 596                 $maxqueues = $queues;
 597
 598                 $active = self::activeWorkers();
 599
 600                 // Decrease the number of workers at higher load
 601                 $load = current_load();
 602                 if ($load) {
 603                         $maxsysload = intval(Config::get("system", "maxloadavg", 50));
 604
 605                         $maxworkers = $queues;
 606
 607                         // Some magical mathemathics to reduce the workers
 608                         $exponent = 3;
 609                         $slope = $maxworkers / pow($maxsysload, $exponent);
 610                         $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 611                         $processlist = '';
 612
 613                         if (Config::get('system', 'worker_debug')) {
 614                                 // Create a list of queue entries grouped by their priority
 615                                 $listitem = [];
 616
 617                                 // Adding all processes with no workerqueue entry
 618                                 $processes = dba::p(
 619                                         "SELECT COUNT(*) AS `running` FROM `process` WHERE NOT EXISTS
 620                                                         (SELECT id FROM `workerqueue`
 621                                                         WHERE `workerqueue`.`pid` = `process`.`pid` AND NOT `done` AND `pid` != ?)",
 622                                         getmypid()
 623                                 );
 624
 625                                 if ($process = dba::fetch($processes)) {
 626                                         $listitem[0] = "0:".$process["running"];
 627                                 }
 628                                 dba::close($processes);
 629
 630                                 // Now adding all processes with workerqueue entries
 631                                 $entries = dba::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 632                                 while ($entry = dba::fetch($entries)) {
 633                                         $processes = dba::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` WHERE `priority` = ?", $entry["priority"]);
 634                                         if ($process = dba::fetch($processes)) {
 635                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 636                                         }
 637                                         dba::close($processes);
 638                                 }
 639                                 dba::close($entries);
 640
 641                                 $intervals = [1, 10, 60];
 642                                 $jobs_per_minute = [];
 643                                 foreach ($intervals as $interval) {
 644                                         $jobs = dba::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ".intval($interval)." MINUTE");
 645                                         if ($job = dba::fetch($jobs)) {
 646                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 647                                         }
 648                                         dba::close($jobs);
 649                                 }
 650                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute).' ('.implode(', ', $listitem).')';
 651                         }
 652
 653                         $entries = self::totalEntries();
 654
 655                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($active >= $queues)) {
 656                                 $top_priority = self::highestPriority();
 657                                 $high_running = self::processWithPriorityActive($top_priority);
 658
 659                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 660                                         logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
 661                                         $queues = $active + 1;
 662                                 }
 663                         }
 664
 665                         logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries.$processlist." - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
 666
 667                         // Are there fewer workers running as possible? Then fork a new one.
 668                         if (!Config::get("system", "worker_dont_fork") && ($queues > ($active + 1)) && ($entries > 1)) {
 669                                 logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
 670                                 self::spawnWorker();
 671                         }
 672                 }
 673
 674                 return $active >= $queues;
 675         }
 676
 677         /**
 678          * @brief Returns the number of active worker processes
 679          *
 680          * @return integer Number of active worker processes
 681          */
 682         private static function activeWorkers()
 683         {
 684                 $workers = dba::fetch_first("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'Worker.php'");
 685
 686                 return $workers["processes"];
 687         }
 688
 689         /**
 690          * @brief Check if we should pass some slow processes
 691          *
 692          * When the active processes of the highest priority are using more than 2/3
 693          * of all processes, we let pass slower processes.
 694          *
 695          * @param string $highest_priority Returns the currently highest priority
 696          * @return bool We let pass a slower process than $highest_priority
 697          */
 698         private static function passingSlow(&$highest_priority)
 699         {
 700                 $highest_priority = 0;
 701
 702                 $r = dba::p(
 703                         "SELECT `priority`
 704                                 FROM `process`
 705                                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done`"
 706                 );
 707
 708                 // No active processes at all? Fine
 709                 if (!DBM::is_result($r)) {
 710                         return false;
 711                 }
 712                 $priorities = [];
 713                 while ($line = dba::fetch($r)) {
 714                         $priorities[] = $line["priority"];
 715                 }
 716                 dba::close($r);
 717
 718                 // Should not happen
 719                 if (count($priorities) == 0) {
 720                         return false;
 721                 }
 722                 $highest_priority = min($priorities);
 723
 724                 // The highest process is already the slowest one?
 725                 // Then we quit
 726                 if ($highest_priority == PRIORITY_NEGLIGIBLE) {
 727                         return false;
 728                 }
 729                 $high = 0;
 730                 foreach ($priorities as $priority) {
 731                         if ($priority == $highest_priority) {
 732                                 ++$high;
 733                         }
 734                 }
 735                 logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
 736                 $passing_slow = (($high/count($priorities)) > (2/3));
 737
 738                 if ($passing_slow) {
 739                         logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
 740                 }
 741                 return $passing_slow;
 742         }
 743
 744         /**
 745          * @brief Find and claim the next worker process for us
 746          *
 747          * @param boolean $passing_slow Returns if we had passed low priority processes
 748          * @return boolean Have we found something?
 749          */
 750         private static function findWorkerProcesses(&$passing_slow)
 751         {
 752                 $mypid = getmypid();
 753
 754                 // Check if we should pass some low priority process
 755                 $highest_priority = 0;
 756                 $found = false;
 757                 $passing_slow = false;
 758
 759                 // The higher the number of parallel workers, the more we prefetch to prevent concurring access
 760                 // We decrease the limit with the number of entries left in the queue
 761                 $worker_queues = Config::get("system", "worker_queues", 4);
 762                 $queue_length = Config::get('system', 'worker_fetch_limit', 1);
 763                 $lower_job_limit = $worker_queues * $queue_length * 2;
 764                 $jobs = self::totalEntries();
 765
 766                 // Now do some magic
 767                 $exponent = 2;
 768                 $slope = $queue_length / pow($lower_job_limit, $exponent);
 769                 $limit = min($queue_length, ceil($slope * pow($jobs, $exponent)));
 770
 771                 logger('Total: '.$jobs.' - Maximum: '.$queue_length.' - jobs per queue: '.$limit, LOGGER_DEBUG);
 772
 773                 if (self::passingSlow($highest_priority)) {
 774                         // Are there waiting processes with a higher priority than the currently highest?
 775                         $result = dba::select(
 776                                 'workerqueue',
 777                                 ['id'],
 778                                 ["`executed` <= ? AND `priority` < ? AND NOT `done`", NULL_DATE, $highest_priority],
 779                                 ['limit' => $limit, 'order' => ['priority', 'created']]
 780                         );
 781
 782                         while ($id = dba::fetch($result)) {
 783                                 $ids[] = $id["id"];
 784                         }
 785                         dba::close($result);
 786
 787                         $found = (count($ids) > 0);
 788
 789                         if (!$found) {
 790                                 // Give slower processes some processing time
 791                                 $result = dba::select(
 792                                         'workerqueue',
 793                                         ['id'],
 794                                         ["`executed` <= ? AND `priority` > ? AND NOT `done`", NULL_DATE, $highest_priority],
 795                                         ['limit' => $limit, 'order' => ['priority', 'created']]
 796                                 );
 797
 798                                 while ($id = dba::fetch($result)) {
 799                                         $ids[] = $id["id"];
 800                                 }
 801                                 dba::close($result);
 802
 803                                 $found = (count($ids) > 0);
 804                                 $passing_slow = $found;
 805                         }
 806                 }
 807
 808                 // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 809                 if (!$found) {
 810                         $result = dba::select(
 811                                 'workerqueue',
 812                                 ['id'],
 813                                 ["`executed` <= ? AND NOT `done`", NULL_DATE],
 814                                 ['limit' => $limit, 'order' => ['priority', 'created']]
 815                         );
 816
 817                         while ($id = dba::fetch($result)) {
 818                                 $ids[] = $id["id"];
 819                         }
 820                         dba::close($result);
 821
 822                         $found = (count($ids) > 0);
 823                 }
 824
 825                 if ($found) {
 826                         $condition = "`id` IN (".substr(str_repeat("?, ", count($ids)), 0, -2).") AND `pid` = 0 AND NOT `done`";
 827                         array_unshift($ids, $condition);
 828                         dba::update('workerqueue', ['executed' => Temporal::utcNow(), 'pid' => $mypid], $ids);
 829                 }
 830
 831                 return $found;
 832         }
 833
 834         /**
 835          * @brief Returns the next worker process
 836          *
 837          * @param boolean $passing_slow Returns if we had passed low priority processes
 838          * @return string SQL statement
 839          */
 840         public static function workerProcess(&$passing_slow)
 841         {
 842                 $stamp = (float)microtime(true);
 843
 844                 // There can already be jobs for us in the queue.
 845                 $r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 846                 if (DBM::is_result($r)) {
 847                         self::$db_duration += (microtime(true) - $stamp);
 848                         return dba::inArray($r);
 849                 }
 850                 dba::close($r);
 851
 852                 $stamp = (float)microtime(true);
 853                 if (!Lock::set('poller_worker_process')) {
 854                         return false;
 855                 }
 856                 self::$lock_duration = (microtime(true) - $stamp);
 857
 858                 $stamp = (float)microtime(true);
 859                 $found = self::findWorkerProcesses($passing_slow);
 860                 self::$db_duration += (microtime(true) - $stamp);
 861
 862                 Lock::remove('poller_worker_process');
 863
 864                 if ($found) {
 865                         $r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 866                         return dba::inArray($r);
 867                 }
 868                 return false;
 869         }
 870
 871         /**
 872          * @brief Removes a workerqueue entry from the current process
 873          * @return void
 874          */
 875         public static function unclaimProcess()
 876         {
 877                 $mypid = getmypid();
 878
 879                 dba::update('workerqueue', ['executed' => NULL_DATE, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 880         }
 881
 882         /**
 883          * @brief Call the front end worker
 884          * @return void
 885          */
 886         public static function callWorker()
 887         {
 888                 if (!Config::get("system", "frontend_worker")) {
 889                         return;
 890                 }
 891
 892                 $url = System::baseUrl()."/worker";
 893                 Network::fetchUrl($url, false, $redirects, 1);
 894         }
 895
 896         /**
 897          * @brief Call the front end worker if there aren't any active
 898          * @return void
 899          */
 900         public static function executeIfIdle()
 901         {
 902                 if (!Config::get("system", "frontend_worker")) {
 903                         return;
 904                 }
 905
 906                 // Do we have "proc_open"? Then we can fork the worker
 907                 if (function_exists("proc_open")) {
 908                         // When was the last time that we called the worker?
 909                         // Less than one minute? Then we quit
 910                         if ((time() - Config::get("system", "worker_started")) < 60) {
 911                                 return;
 912                         }
 913
 914                         Config::set("system", "worker_started", time());
 915
 916                         // Do we have enough running workers? Then we quit here.
 917                         if (self::tooMuchWorkers()) {
 918                                 // Cleaning dead processes
 919                                 self::killStaleWorkers();
 920                                 Process::deleteInactive();
 921
 922                                 return;
 923                         }
 924
 925                         self::runCron();
 926
 927                         logger('Call worker', LOGGER_DEBUG);
 928                         self::spawnWorker();
 929                         return;
 930                 }
 931
 932                 // We cannot execute background processes.
 933                 // We now run the processes from the frontend.
 934                 // This won't work with long running processes.
 935                 self::runCron();
 936
 937                 self::clearProcesses();
 938
 939                 $workers = dba::fetch_first("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'worker.php'");
 940
 941                 if ($workers["processes"] == 0) {
 942                         self::callWorker();
 943                 }
 944         }
 945
 946         /**
 947          * @brief Removes long running worker processes
 948          * @return void
 949          */
 950         public static function clearProcesses()
 951         {
 952                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
 953
 954                 /// @todo We should clean up the corresponding workerqueue entries as well
 955                 $condition = ["`created` < ? AND `command` = 'worker.php'",
 956                                 Temporal::convert("now - ".$timeout." minutes")];
 957                 dba::delete('process', $condition);
 958         }
 959
 960         /**
 961          * @brief Runs the cron processes
 962          * @return void
 963          */
 964         private static function runCron()
 965         {
 966                 logger('Add cron entries', LOGGER_DEBUG);
 967
 968                 // Check for spooled items
 969                 self::add(PRIORITY_HIGH, "SpoolPost");
 970
 971                 // Run the cron job that calls all other jobs
 972                 self::add(PRIORITY_MEDIUM, "Cron");
 973
 974                 // Run the cronhooks job separately from cron for being able to use a different timing
 975                 self::add(PRIORITY_MEDIUM, "CronHooks");
 976
 977                 // Cleaning dead processes
 978                 self::killStaleWorkers();
 979         }
 980
 981         /**
 982          * @return void
 983          */
 984         public static function spawnWorker()
 985         {
 986                 $args = ["scripts/worker.php", "no_cron"];
 987                 get_app()->proc_run($args);
 988         }
 989
 990         /**
 991          * @brief Adds tasks to the worker queue
 992          *
 993          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
 994          *
 995          * next args are passed as $cmd command line
 996          * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
 997          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
 998          *
 999          * @note $cmd and string args are surrounded with ""
1000          *
1001          * @hooks 'proc_run'
1002          *      array $arr
1003          *
1004          * @return boolean "false" if proc_run couldn't be executed
1005          */
1006         public static function add($cmd)
1007         {
1008                 $proc_args = func_get_args();
1009
1010                 $args = [];
1011                 if (!count($proc_args)) {
1012                         return false;
1013                 }
1014
1015                 // Preserve the first parameter
1016                 // It could contain a command, the priority or an parameter array
1017                 // If we use the parameter array we have to protect it from the following function
1018                 $run_parameter = array_shift($proc_args);
1019
1020                 // expand any arrays
1021                 foreach ($proc_args as $arg) {
1022                         if (is_array($arg)) {
1023                                 foreach ($arg as $n) {
1024                                         $args[] = $n;
1025                                 }
1026                         } else {
1027                                 $args[] = $arg;
1028                         }
1029                 }
1030
1031                 // Now we add the run parameters back to the array
1032                 array_unshift($args, $run_parameter);
1033
1034                 $arr = ['args' => $args, 'run_cmd' => true];
1035
1036                 Addon::callHooks("proc_run", $arr);
1037                 if (!$arr['run_cmd'] || !count($args)) {
1038                         return true;
1039                 }
1040
1041                 $priority = PRIORITY_MEDIUM;
1042                 $dont_fork = Config::get("system", "worker_dont_fork");
1043                 $created = Temporal::utcNow();
1044
1045                 if (is_int($run_parameter)) {
1046                         $priority = $run_parameter;
1047                 } elseif (is_array($run_parameter)) {
1048                         if (isset($run_parameter['priority'])) {
1049                                 $priority = $run_parameter['priority'];
1050                         }
1051                         if (isset($run_parameter['created'])) {
1052                                 $created = $run_parameter['created'];
1053                         }
1054                         if (isset($run_parameter['dont_fork'])) {
1055                                 $dont_fork = $run_parameter['dont_fork'];
1056                         }
1057                 }
1058
1059                 $argv = $args;
1060                 array_shift($argv);
1061
1062                 $parameters = json_encode($argv);
1063                 $found = dba::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1064
1065                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1066                 if (dba::errorNo() != 0) {
1067                         return false;
1068                 }
1069
1070                 if (!$found) {
1071                         dba::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1072                 }
1073
1074                 // Should we quit and wait for the worker to be called as a cronjob?
1075                 if ($dont_fork) {
1076                         return true;
1077                 }
1078
1079                 // If there is a lock then we don't have to check for too much worker
1080                 if (!Lock::set('poller_worker', 0)) {
1081                         return true;
1082                 }
1083
1084                 // If there are already enough workers running, don't fork another one
1085                 $quit = self::tooMuchWorkers();
1086                 Lock::remove('poller_worker');
1087
1088                 if ($quit) {
1089                         return true;
1090                 }
1091
1092                 // Now call the worker to execute the jobs that we just added to the queue
1093                 self::spawnWorker();
1094
1095                 return true;
1096         }
1097
1098         /**
1099          * Log active processes into the "process" table
1100          *
1101          * @brief Log active processes into the "process" table
1102          */
1103         public static function startProcess()
1104         {
1105                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1106
1107                 $command = basename($trace[0]['file']);
1108
1109                 Process::deleteInactive();
1110
1111                 Process::insert($command);
1112         }
1113
1114         /**
1115          * Remove the active process from the "process" table
1116          *
1117          * @brief Remove the active process from the "process" table
1118          * @return bool
1119          */
1120         public static function endProcess()
1121         {
1122                 return Process::deleteByPid();
1123         }
1124 }