src/Core/Worker.php

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