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                 $last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
  58                 if (time() > ($last_cleanup + 300)) {
  59                         Config::set('system', 'worker_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('worker_process', 0)) {
 112                                         $stamp = (float)microtime(true);
 113                                         $refetched = self::findWorkerProcesses($passing_slow);
 114                                         self::$db_duration += (microtime(true) - $stamp);
 115                                         Lock::remove('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('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('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
 144                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 145                 if (Config::get('system', 'worker_daemon_mode', false)) {
 146                         self::IPCSetJobState(false);
 147                 }
 148                 logger("Couldn't select a workerqueue entry, quitting.", LOGGER_DEBUG);
 149         }
 150
 151         /**
 152          * @brief Returns the number of non executed entries in the worker queue
 153          *
 154          * @return integer Number of non executed entries in the worker queue
 155          */
 156         private static function totalEntries()
 157         {
 158                 $s = dba::fetch_first("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` <= ? AND NOT `done`", NULL_DATE);
 159                 if (DBM::is_result($s)) {
 160                         return $s["total"];
 161                 } else {
 162                         return 0;
 163                 }
 164         }
 165
 166         /**
 167          * @brief Returns the highest priority in the worker queue that isn't executed
 168          *
 169          * @return integer Number of active worker processes
 170          */
 171         private static function highestPriority()
 172         {
 173                 $condition = ["`executed` <= ? AND NOT `done`", NULL_DATE];
 174                 $workerqueue = dba::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 175                 if (DBM::is_result($workerqueue)) {
 176                         return $workerqueue["priority"];
 177                 } else {
 178                         return 0;
 179                 }
 180         }
 181
 182         /**
 183          * @brief Returns if a process with the given priority is running
 184          *
 185          * @param integer $priority The priority that should be checked
 186          *
 187          * @return integer Is there a process running with that priority?
 188          */
 189         private static function processWithPriorityActive($priority)
 190         {
 191                 $condition = ["`priority` <= ? AND `executed` > ? AND NOT `done`", $priority, NULL_DATE];
 192                 return dba::exists('workerqueue', $condition);
 193         }
 194
 195         /**
 196          * @brief Execute a worker entry
 197          *
 198          * @param array $queue Workerqueue entry
 199          *
 200          * @return boolean "true" if further processing should be stopped
 201          */
 202         public static function execute($queue)
 203         {
 204                 $a = get_app();
 205
 206                 $mypid = getmypid();
 207
 208                 // Quit when in maintenance
 209                 if (Config::get('system', 'maintenance', false, true)) {
 210                         logger("Maintenance mode - quit process ".$mypid, LOGGER_DEBUG);
 211                         return false;
 212                 }
 213
 214                 // Constantly check the number of parallel database processes
 215                 if ($a->max_processes_reached()) {
 216                         logger("Max processes reached for process ".$mypid, LOGGER_DEBUG);
 217                         return false;
 218                 }
 219
 220                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 221                 if (self::maxConnectionsReached()) {
 222                         logger("Max connection reached for process ".$mypid, LOGGER_DEBUG);
 223                         return false;
 224                 }
 225
 226                 $argv = json_decode($queue["parameter"], true);
 227
 228                 // Check for existance and validity of the include file
 229                 $include = $argv[0];
 230
 231                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 232                         // We constantly update the "executed" date every minute to avoid being killed too soon
 233                         if (!isset(self::$last_update)) {
 234                                 self::$last_update = strtotime($queue["executed"]);
 235                         }
 236
 237                         $age = (time() - self::$last_update) / 60;
 238                         self::$last_update = time();
 239
 240                         if ($age > 1) {
 241                                 $stamp = (float)microtime(true);
 242                                 dba::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 243                                 self::$db_duration += (microtime(true) - $stamp);
 244                         }
 245
 246                         array_shift($argv);
 247
 248                         self::execFunction($queue, $include, $argv, true);
 249
 250                         $stamp = (float)microtime(true);
 251                         if (dba::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 252                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 253                         }
 254                         self::$db_duration = (microtime(true) - $stamp);
 255
 256                         return true;
 257                 }
 258
 259                 // The script could be provided as full path or only with the function name
 260                 if ($include == basename($include)) {
 261                         $include = "include/".$include.".php";
 262                 }
 263
 264                 if (!validate_include($include)) {
 265                         logger("Include file ".$argv[0]." is not valid!");
 266                         dba::delete('workerqueue', ['id' => $queue["id"]]);
 267                         return true;
 268                 }
 269
 270                 require_once $include;
 271
 272                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 273
 274                 if (function_exists($funcname)) {
 275                         // We constantly update the "executed" date every minute to avoid being killed too soon
 276                         if (!isset(self::$last_update)) {
 277                                 self::$last_update = strtotime($queue["executed"]);
 278                         }
 279
 280                         $age = (time() - self::$last_update) / 60;
 281                         self::$last_update = time();
 282
 283                         if ($age > 1) {
 284                                 $stamp = (float)microtime(true);
 285                                 dba::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 286                                 self::$db_duration += (microtime(true) - $stamp);
 287                         }
 288
 289                         self::execFunction($queue, $funcname, $argv, false);
 290
 291                         $stamp = (float)microtime(true);
 292                         if (dba::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 293                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 294                         }
 295                         self::$db_duration = (microtime(true) - $stamp);
 296                 } else {
 297                         logger("Function ".$funcname." does not exist");
 298                         dba::delete('workerqueue', ['id' => $queue["id"]]);
 299                 }
 300
 301                 return true;
 302         }
 303
 304         /**
 305          * @brief Execute a function from the queue
 306          *
 307          * @param array   $queue       Workerqueue entry
 308          * @param string  $funcname    name of the function
 309          * @param array   $argv        Array of values to be passed to the function
 310          * @param boolean $method_call boolean
 311          * @return void
 312          */
 313         private static function execFunction($queue, $funcname, $argv, $method_call)
 314         {
 315                 $a = get_app();
 316
 317                 $mypid = getmypid();
 318
 319                 $argc = count($argv);
 320
 321                 $new_process_id = uniqid("wrk", true);
 322
 323                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
 324
 325                 $stamp = (float)microtime(true);
 326
 327                 // We use the callstack here to analyze the performance of executed worker entries.
 328                 // For this reason the variables have to be initialized.
 329                 if (Config::get("system", "profiler")) {
 330                         $a->performance["start"] = microtime(true);
 331                         $a->performance["database"] = 0;
 332                         $a->performance["database_write"] = 0;
 333                         $a->performance["cache"] = 0;
 334                         $a->performance["cache_write"] = 0;
 335                         $a->performance["network"] = 0;
 336                         $a->performance["file"] = 0;
 337                         $a->performance["rendering"] = 0;
 338                         $a->performance["parser"] = 0;
 339                         $a->performance["marktime"] = 0;
 340                         $a->performance["markstart"] = microtime(true);
 341                         $a->callstack = [];
 342                 }
 343
 344                 // For better logging create a new process id for every worker call
 345                 // But preserve the old one for the worker
 346                 $old_process_id = $a->process_id;
 347                 $a->process_id = $new_process_id;
 348                 $a->queue = $queue;
 349
 350                 $up_duration = number_format(microtime(true) - self::$up_start, 3);
 351
 352                 // Reset global data to avoid interferences
 353                 unset($_SESSION);
 354
 355                 if ($method_call) {
 356                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 357                 } else {
 358                         $funcname($argv, $argc);
 359                 }
 360
 361                 $a->process_id = $old_process_id;
 362                 unset($a->queue);
 363
 364                 $duration = number_format(microtime(true) - $stamp, 3);
 365
 366                 self::$up_start = microtime(true);
 367
 368                 /* With these values we can analyze how effective the worker is.
 369                  * The database and rest time should be low since this is the unproductive time.
 370                  * The execution time is the productive time.
 371                  * By changing parameters like the maximum number of workers we can check the effectivness.
 372                 */
 373                 logger(
 374                         'DB: '.number_format(self::$db_duration, 2).
 375                         ' - Lock: '.number_format(self::$lock_duration, 2).
 376                         ' - Rest: '.number_format($up_duration - self::$db_duration - self::$lock_duration, 2).
 377                         ' - Execution: '.number_format($duration, 2),
 378                         LOGGER_DEBUG
 379                 );
 380
 381                 self::$lock_duration = 0;
 382
 383                 if ($duration > 3600) {
 384                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", LOGGER_DEBUG);
 385                 } elseif ($duration > 600) {
 386                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 387                 } elseif ($duration > 300) {
 388                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 389                 } elseif ($duration > 120) {
 390                         logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 391                 }
 392
 393                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds. Process PID: ".$new_process_id);
 394
 395                 // Write down the performance values into the log
 396                 if (Config::get("system", "profiler")) {
 397                         $duration = microtime(true)-$a->performance["start"];
 398
 399                         $o = '';
 400                         if (Config::get("rendertime", "callstack")) {
 401                                 if (isset($a->callstack["database"])) {
 402                                         $o .= "\nDatabase Read:\n";
 403                                         foreach ($a->callstack["database"] as $func => $time) {
 404                                                 $time = round($time, 3);
 405                                                 if ($time > 0) {
 406                                                         $o .= $func.": ".$time."\n";
 407                                                 }
 408                                         }
 409                                 }
 410                                 if (isset($a->callstack["database_write"])) {
 411                                         $o .= "\nDatabase Write:\n";
 412                                         foreach ($a->callstack["database_write"] as $func => $time) {
 413                                                 $time = round($time, 3);
 414                                                 if ($time > 0) {
 415                                                         $o .= $func.": ".$time."\n";
 416                                                 }
 417                                         }
 418                                 }
 419                                 if (isset($a->callstack["dache"])) {
 420                                         $o .= "\nCache Read:\n";
 421                                         foreach ($a->callstack["dache"] as $func => $time) {
 422                                                 $time = round($time, 3);
 423                                                 if ($time > 0) {
 424                                                         $o .= $func.": ".$time."\n";
 425                                                 }
 426                                         }
 427                                 }
 428                                 if (isset($a->callstack["dache_write"])) {
 429                                         $o .= "\nCache Write:\n";
 430                                         foreach ($a->callstack["dache_write"] as $func => $time) {
 431                                                 $time = round($time, 3);
 432                                                 if ($time > 0) {
 433                                                         $o .= $func.": ".$time."\n";
 434                                                 }
 435                                         }
 436                                 }
 437                                 if (isset($a->callstack["network"])) {
 438                                         $o .= "\nNetwork:\n";
 439                                         foreach ($a->callstack["network"] as $func => $time) {
 440                                                 $time = round($time, 3);
 441                                                 if ($time > 0) {
 442                                                         $o .= $func.": ".$time."\n";
 443                                                 }
 444                                         }
 445                                 }
 446                         }
 447
 448                         logger(
 449                                 "ID ".$queue["id"].": ".$funcname.": ".sprintf(
 450                                         "DB: %s/%s, Cache: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
 451                                         number_format($a->performance["database"] - $a->performance["database_write"], 2),
 452                                         number_format($a->performance["database_write"], 2),
 453                                         number_format($a->performance["cache"], 2),
 454                                         number_format($a->performance["cache_write"], 2),
 455                                         number_format($a->performance["network"], 2),
 456                                         number_format($a->performance["file"], 2),
 457                                         number_format($duration - ($a->performance["database"]
 458                                                 + $a->performance["cache"] + $a->performance["cache_write"]
 459                                                 + $a->performance["network"] + $a->performance["file"]), 2),
 460                                         number_format($duration, 2)
 461                                 ),
 462                                 LOGGER_DEBUG
 463                         );
 464                 }
 465
 466                 $cooldown = Config::get("system", "worker_cooldown", 0);
 467
 468                 if ($cooldown > 0) {
 469                         logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 470                         sleep($cooldown);
 471                 }
 472         }
 473
 474         /**
 475          * @brief Checks if the number of database connections has reached a critical limit.
 476          *
 477          * @return bool Are more than 3/4 of the maximum connections used?
 478          */
 479         private static function maxConnectionsReached()
 480         {
 481                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 482                 $max = Config::get("system", "max_connections");
 483
 484                 // Fetch the percentage level where the worker will get active
 485                 $maxlevel = Config::get("system", "max_connections_level", 75);
 486
 487                 if ($max == 0) {
 488                         // the maximum number of possible user connections can be a system variable
 489                         $r = dba::fetch_first("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 490                         if (DBM::is_result($r)) {
 491                                 $max = $r["Value"];
 492                         }
 493                         // Or it can be granted. This overrides the system variable
 494                         $r = dba::p('SHOW GRANTS');
 495                         while ($grants = dba::fetch($r)) {
 496                                 $grant = array_pop($grants);
 497                                 if (stristr($grant, "GRANT USAGE ON")) {
 498                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 499                                                 $max = $match[1];
 500                                         }
 501                                 }
 502                         }
 503                         dba::close($r);
 504                 }
 505
 506                 // If $max is set we will use the processlist to determine the current number of connections
 507                 // The processlist only shows entries of the current user
 508                 if ($max != 0) {
 509                         $r = dba::p('SHOW PROCESSLIST');
 510                         $used = dba::num_rows($r);
 511                         dba::close($r);
 512
 513                         logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 514
 515                         $level = ($used / $max) * 100;
 516
 517                         if ($level >= $maxlevel) {
 518                                 logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 519                                 return true;
 520                         }
 521                 }
 522
 523                 // We will now check for the system values.
 524                 // This limit could be reached although the user limits are fine.
 525                 $r = dba::fetch_first("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 526                 if (!DBM::is_result($r)) {
 527                         return false;
 528                 }
 529                 $max = intval($r["Value"]);
 530                 if ($max == 0) {
 531                         return false;
 532                 }
 533                 $r = dba::fetch_first("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 534                 if (!DBM::is_result($r)) {
 535                         return false;
 536                 }
 537                 $used = intval($r["Value"]);
 538                 if ($used == 0) {
 539                         return false;
 540                 }
 541                 logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 542
 543                 $level = $used / $max * 100;
 544
 545                 if ($level < $maxlevel) {
 546                         return false;
 547                 }
 548                 logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 549                 return true;
 550         }
 551
 552         /**
 553          * @brief fix the queue entry if the worker process died
 554          * @return void
 555          */
 556         private static function killStaleWorkers()
 557         {
 558                 $entries = dba::select(
 559                         'workerqueue',
 560                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 561                         ['`executed` > ? AND NOT `done` AND `pid` != 0', NULL_DATE],
 562                         ['order' => ['priority', 'created']]
 563                 );
 564
 565                 while ($entry = dba::fetch($entries)) {
 566                         if (!posix_kill($entry["pid"], 0)) {
 567                                 dba::update(
 568                                         'workerqueue',
 569                                         ['executed' => NULL_DATE, 'pid' => 0],
 570                                         ['id' => $entry["id"]]
 571                                 );
 572                         } else {
 573                                 // Kill long running processes
 574                                 // Check if the priority is in a valid range
 575                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 576                                         $entry["priority"] = PRIORITY_MEDIUM;
 577                                 }
 578
 579                                 // Define the maximum durations
 580                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 581                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 582
 583                                 $argv = json_decode($entry["parameter"], true);
 584                                 $argv[0] = basename($argv[0]);
 585
 586                                 // How long is the process already running?
 587                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 588                                 if ($duration > $max_duration) {
 589                                         logger("Worker process ".$entry["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
 590                                         posix_kill($entry["pid"], SIGTERM);
 591
 592                                         // We killed the stale process.
 593                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 594                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 595                                         $new_priority = $entry["priority"];
 596                                         if ($entry["priority"] == PRIORITY_HIGH) {
 597                                                 $new_priority = PRIORITY_MEDIUM;
 598                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 599                                                 $new_priority = PRIORITY_LOW;
 600                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 601                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 602                                         }
 603                                         dba::update(
 604                                                 'workerqueue',
 605                                                 ['executed' => NULL_DATE, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 606                                                 ['id' => $entry["id"]]
 607                                         );
 608                                 } else {
 609                                         logger("Worker process ".$entry["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
 610                                 }
 611                         }
 612                 }
 613         }
 614
 615         /**
 616          * @brief Checks if the number of active workers exceeds the given limits
 617          *
 618          * @return bool Are there too much workers running?
 619          */
 620         public static function tooMuchWorkers()
 621         {
 622                 $queues = Config::get("system", "worker_queues", 4);
 623
 624                 $maxqueues = $queues;
 625
 626                 $active = self::activeWorkers();
 627
 628                 // Decrease the number of workers at higher load
 629                 $load = current_load();
 630                 if ($load) {
 631                         $maxsysload = intval(Config::get("system", "maxloadavg", 50));
 632
 633                         $maxworkers = $queues;
 634
 635                         // Some magical mathemathics to reduce the workers
 636                         $exponent = 3;
 637                         $slope = $maxworkers / pow($maxsysload, $exponent);
 638                         $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 639                         $processlist = '';
 640
 641                         if (Config::get('system', 'worker_debug')) {
 642                                 // Create a list of queue entries grouped by their priority
 643                                 $listitem = [];
 644
 645                                 // Adding all processes with no workerqueue entry
 646                                 $processes = dba::p(
 647                                         "SELECT COUNT(*) AS `running` FROM `process` WHERE NOT EXISTS
 648                                                         (SELECT id FROM `workerqueue`
 649                                                         WHERE `workerqueue`.`pid` = `process`.`pid` AND NOT `done` AND `pid` != ?)",
 650                                         getmypid()
 651                                 );
 652
 653                                 if ($process = dba::fetch($processes)) {
 654                                         $listitem[0] = "0:".$process["running"];
 655                                 }
 656                                 dba::close($processes);
 657
 658                                 // Now adding all processes with workerqueue entries
 659                                 $entries = dba::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 660                                 while ($entry = dba::fetch($entries)) {
 661                                         $processes = dba::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` WHERE `priority` = ?", $entry["priority"]);
 662                                         if ($process = dba::fetch($processes)) {
 663                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 664                                         }
 665                                         dba::close($processes);
 666                                 }
 667                                 dba::close($entries);
 668
 669                                 $intervals = [1, 10, 60];
 670                                 $jobs_per_minute = [];
 671                                 foreach ($intervals as $interval) {
 672                                         $jobs = dba::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ".intval($interval)." MINUTE");
 673                                         if ($job = dba::fetch($jobs)) {
 674                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 675                                         }
 676                                         dba::close($jobs);
 677                                 }
 678                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute).' ('.implode(', ', $listitem).')';
 679                         }
 680
 681                         $entries = self::totalEntries();
 682
 683                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($active >= $queues)) {
 684                                 $top_priority = self::highestPriority();
 685                                 $high_running = self::processWithPriorityActive($top_priority);
 686
 687                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 688                                         logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
 689                                         $queues = $active + 1;
 690                                 }
 691                         }
 692
 693                         logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries.$processlist." - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
 694
 695                         // Are there fewer workers running as possible? Then fork a new one.
 696                         if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && ($entries > 1)) {
 697                                 logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
 698                                 if (Config::get('system', 'worker_daemon_mode', false)) {
 699                                         self::IPCSetJobState(true);
 700                                 } else {
 701                                         self::spawnWorker();
 702                                 }
 703                         }
 704                 }
 705
 706                 // if there are too much worker, we down't spawn a new one.
 707                 if (Config::get('system', 'worker_daemon_mode', false) && ($active >= $queues)) {
 708                         self::IPCSetJobState(false);
 709                 }
 710
 711                 return $active >= $queues;
 712         }
 713
 714         /**
 715          * @brief Returns the number of active worker processes
 716          *
 717          * @return integer Number of active worker processes
 718          */
 719         private static function activeWorkers()
 720         {
 721                 $workers = dba::fetch_first("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'Worker.php'");
 722
 723                 return $workers["processes"];
 724         }
 725
 726         /**
 727          * @brief Check if we should pass some slow processes
 728          *
 729          * When the active processes of the highest priority are using more than 2/3
 730          * of all processes, we let pass slower processes.
 731          *
 732          * @param string $highest_priority Returns the currently highest priority
 733          * @return bool We let pass a slower process than $highest_priority
 734          */
 735         private static function passingSlow(&$highest_priority)
 736         {
 737                 $highest_priority = 0;
 738
 739                 $r = dba::p(
 740                         "SELECT `priority`
 741                                 FROM `process`
 742                                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done`"
 743                 );
 744
 745                 // No active processes at all? Fine
 746                 if (!DBM::is_result($r)) {
 747                         return false;
 748                 }
 749                 $priorities = [];
 750                 while ($line = dba::fetch($r)) {
 751                         $priorities[] = $line["priority"];
 752                 }
 753                 dba::close($r);
 754
 755                 // Should not happen
 756                 if (count($priorities) == 0) {
 757                         return false;
 758                 }
 759                 $highest_priority = min($priorities);
 760
 761                 // The highest process is already the slowest one?
 762                 // Then we quit
 763                 if ($highest_priority == PRIORITY_NEGLIGIBLE) {
 764                         return false;
 765                 }
 766                 $high = 0;
 767                 foreach ($priorities as $priority) {
 768                         if ($priority == $highest_priority) {
 769                                 ++$high;
 770                         }
 771                 }
 772                 logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
 773                 $passing_slow = (($high/count($priorities)) > (2/3));
 774
 775                 if ($passing_slow) {
 776                         logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
 777                 }
 778                 return $passing_slow;
 779         }
 780
 781         /**
 782          * @brief Find and claim the next worker process for us
 783          *
 784          * @param boolean $passing_slow Returns if we had passed low priority processes
 785          * @return boolean Have we found something?
 786          */
 787         private static function findWorkerProcesses(&$passing_slow)
 788         {
 789                 $mypid = getmypid();
 790
 791                 // Check if we should pass some low priority process
 792                 $highest_priority = 0;
 793                 $found = false;
 794                 $passing_slow = false;
 795
 796                 // The higher the number of parallel workers, the more we prefetch to prevent concurring access
 797                 // We decrease the limit with the number of entries left in the queue
 798                 $worker_queues = Config::get("system", "worker_queues", 4);
 799                 $queue_length = Config::get('system', 'worker_fetch_limit', 1);
 800                 $lower_job_limit = $worker_queues * $queue_length * 2;
 801                 $jobs = self::totalEntries();
 802
 803                 // Now do some magic
 804                 $exponent = 2;
 805                 $slope = $queue_length / pow($lower_job_limit, $exponent);
 806                 $limit = min($queue_length, ceil($slope * pow($jobs, $exponent)));
 807
 808                 logger('Total: '.$jobs.' - Maximum: '.$queue_length.' - jobs per queue: '.$limit, LOGGER_DEBUG);
 809                 $ids = [];
 810                 if (self::passingSlow($highest_priority)) {
 811                         // Are there waiting processes with a higher priority than the currently highest?
 812                         $result = dba::select(
 813                                 'workerqueue',
 814                                 ['id'],
 815                                 ["`executed` <= ? AND `priority` < ? AND NOT `done`", NULL_DATE, $highest_priority],
 816                                 ['limit' => $limit, 'order' => ['priority', 'created']]
 817                         );
 818
 819                         while ($id = dba::fetch($result)) {
 820                                 $ids[] = $id["id"];
 821                         }
 822                         dba::close($result);
 823
 824                         $found = (count($ids) > 0);
 825
 826                         if (!$found) {
 827                                 // Give slower processes some processing time
 828                                 $result = dba::select(
 829                                         'workerqueue',
 830                                         ['id'],
 831                                         ["`executed` <= ? AND `priority` > ? AND NOT `done`", NULL_DATE, $highest_priority],
 832                                         ['limit' => $limit, 'order' => ['priority', 'created']]
 833                                 );
 834
 835                                 while ($id = dba::fetch($result)) {
 836                                         $ids[] = $id["id"];
 837                                 }
 838                                 dba::close($result);
 839
 840                                 $found = (count($ids) > 0);
 841                                 $passing_slow = $found;
 842                         }
 843                 }
 844
 845                 // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 846                 if (!$found) {
 847                         $result = dba::select(
 848                                 'workerqueue',
 849                                 ['id'],
 850                                 ["`executed` <= ? AND NOT `done`", NULL_DATE],
 851                                 ['limit' => $limit, 'order' => ['priority', 'created']]
 852                         );
 853
 854                         while ($id = dba::fetch($result)) {
 855                                 $ids[] = $id["id"];
 856                         }
 857                         dba::close($result);
 858
 859                         $found = (count($ids) > 0);
 860                 }
 861
 862                 if ($found) {
 863                         $condition = "`id` IN (".substr(str_repeat("?, ", count($ids)), 0, -2).") AND `pid` = 0 AND NOT `done`";
 864                         array_unshift($ids, $condition);
 865                         dba::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $ids);
 866                 }
 867
 868                 return $found;
 869         }
 870
 871         /**
 872          * @brief Returns the next worker process
 873          *
 874          * @param boolean $passing_slow Returns if we had passed low priority processes
 875          * @return string SQL statement
 876          */
 877         public static function workerProcess(&$passing_slow)
 878         {
 879                 $stamp = (float)microtime(true);
 880
 881                 // There can already be jobs for us in the queue.
 882                 $r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 883                 if (DBM::is_result($r)) {
 884                         self::$db_duration += (microtime(true) - $stamp);
 885                         return dba::inArray($r);
 886                 }
 887                 dba::close($r);
 888
 889                 $stamp = (float)microtime(true);
 890                 if (!Lock::set('worker_process')) {
 891                         return false;
 892                 }
 893                 self::$lock_duration = (microtime(true) - $stamp);
 894
 895                 $stamp = (float)microtime(true);
 896                 $found = self::findWorkerProcesses($passing_slow);
 897                 self::$db_duration += (microtime(true) - $stamp);
 898
 899                 Lock::remove('worker_process');
 900
 901                 if ($found) {
 902                         $r = dba::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 903                         return dba::inArray($r);
 904                 }
 905                 return false;
 906         }
 907
 908         /**
 909          * @brief Removes a workerqueue entry from the current process
 910          * @return void
 911          */
 912         public static function unclaimProcess()
 913         {
 914                 $mypid = getmypid();
 915
 916                 dba::update('workerqueue', ['executed' => NULL_DATE, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 917         }
 918
 919         /**
 920          * @brief Call the front end worker
 921          * @return void
 922          */
 923         public static function callWorker()
 924         {
 925                 if (!Config::get("system", "frontend_worker")) {
 926                         return;
 927                 }
 928
 929                 $url = System::baseUrl()."/worker";
 930                 Network::fetchUrl($url, false, $redirects, 1);
 931         }
 932
 933         /**
 934          * @brief Call the front end worker if there aren't any active
 935          * @return void
 936          */
 937         public static function executeIfIdle()
 938         {
 939                 if (!Config::get("system", "frontend_worker")) {
 940                         return;
 941                 }
 942
 943                 // Do we have "proc_open"? Then we can fork the worker
 944                 if (function_exists("proc_open")) {
 945                         // When was the last time that we called the worker?
 946                         // Less than one minute? Then we quit
 947                         if ((time() - Config::get("system", "worker_started")) < 60) {
 948                                 return;
 949                         }
 950
 951                         Config::set("system", "worker_started", time());
 952
 953                         // Do we have enough running workers? Then we quit here.
 954                         if (self::tooMuchWorkers()) {
 955                                 // Cleaning dead processes
 956                                 self::killStaleWorkers();
 957                                 Process::deleteInactive();
 958
 959                                 return;
 960                         }
 961
 962                         self::runCron();
 963
 964                         logger('Call worker', LOGGER_DEBUG);
 965                         self::spawnWorker();
 966                         return;
 967                 }
 968
 969                 // We cannot execute background processes.
 970                 // We now run the processes from the frontend.
 971                 // This won't work with long running processes.
 972                 self::runCron();
 973
 974                 self::clearProcesses();
 975
 976                 $workers = dba::fetch_first("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'worker.php'");
 977
 978                 if ($workers["processes"] == 0) {
 979                         self::callWorker();
 980                 }
 981         }
 982
 983         /**
 984          * @brief Removes long running worker processes
 985          * @return void
 986          */
 987         public static function clearProcesses()
 988         {
 989                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
 990
 991                 /// @todo We should clean up the corresponding workerqueue entries as well
 992                 $condition = ["`created` < ? AND `command` = 'worker.php'",
 993                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
 994                 dba::delete('process', $condition);
 995         }
 996
 997         /**
 998          * @brief Runs the cron processes
 999          * @return void
1000          */
1001         private static function runCron()
1002         {
1003                 logger('Add cron entries', LOGGER_DEBUG);
1004
1005                 // Check for spooled items
1006                 self::add(PRIORITY_HIGH, "SpoolPost");
1007
1008                 // Run the cron job that calls all other jobs
1009                 self::add(PRIORITY_MEDIUM, "Cron");
1010
1011                 // Cleaning dead processes
1012                 self::killStaleWorkers();
1013         }
1014
1015         /**
1016          * @brief Spawns a new worker
1017          * @return void
1018          */
1019         public static function spawnWorker($do_cron = false)
1020         {
1021                 $args = ["bin/worker.php"];
1022
1023                 if (!$do_cron) {
1024                         $args[] = "no_cron";
1025                 }
1026
1027                 get_app()->proc_run($args);
1028
1029                 // after spawning we have to remove the flag.
1030                 if (Config::get('system', 'worker_daemon_mode', false)) {
1031                         self::IPCSetJobState(false);
1032                 }
1033         }
1034
1035         /**
1036          * @brief Adds tasks to the worker queue
1037          *
1038          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1039          *
1040          * next args are passed as $cmd command line
1041          * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
1042          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1043          *
1044          * @note $cmd and string args are surrounded with ""
1045          *
1046          * @hooks 'proc_run'
1047          *      array $arr
1048          *
1049          * @return boolean "false" if proc_run couldn't be executed
1050          */
1051         public static function add($cmd)
1052         {
1053                 $args = func_get_args();
1054
1055                 if (!count($args)) {
1056                         return false;
1057                 }
1058
1059                 $arr = ['args' => $args, 'run_cmd' => true];
1060
1061                 Addon::callHooks("proc_run", $arr);
1062                 if (!$arr['run_cmd'] || !count($args)) {
1063                         return true;
1064                 }
1065
1066                 $priority = PRIORITY_MEDIUM;
1067                 $dont_fork = Config::get("system", "worker_dont_fork", false);
1068                 $created = DateTimeFormat::utcNow();
1069
1070                 $run_parameter = array_shift($args);
1071
1072                 if (is_int($run_parameter)) {
1073                         $priority = $run_parameter;
1074                 } elseif (is_array($run_parameter)) {
1075                         if (isset($run_parameter['priority'])) {
1076                                 $priority = $run_parameter['priority'];
1077                         }
1078                         if (isset($run_parameter['created'])) {
1079                                 $created = $run_parameter['created'];
1080                         }
1081                         if (isset($run_parameter['dont_fork'])) {
1082                                 $dont_fork = $run_parameter['dont_fork'];
1083                         }
1084                 }
1085
1086                 $parameters = json_encode($args);
1087                 $found = dba::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1088
1089                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1090                 if (dba::errorNo() != 0) {
1091                         return false;
1092                 }
1093
1094                 if (!$found) {
1095                         dba::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1096                 }
1097
1098                 // Should we quit and wait for the worker to be called as a cronjob?
1099                 if ($dont_fork) {
1100                         return true;
1101                 }
1102
1103                 // If there is a lock then we don't have to check for too much worker
1104                 if (!Lock::set('worker', 0)) {
1105                         return true;
1106                 }
1107
1108                 // If there are already enough workers running, don't fork another one
1109                 $quit = self::tooMuchWorkers();
1110                 Lock::remove('worker');
1111
1112                 if ($quit) {
1113                         return true;
1114                 }
1115
1116                 // We tell the daemon that a new job entry exists
1117                 if (Config::get('system', 'worker_daemon_mode', false)) {
1118                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1119                         return true;
1120                 }
1121
1122                 // Now call the worker to execute the jobs that we just added to the queue
1123                 self::spawnWorker();
1124
1125                 return true;
1126         }
1127
1128         /**
1129          * Log active processes into the "process" table
1130          *
1131          * @brief Log active processes into the "process" table
1132          */
1133         public static function startProcess()
1134         {
1135                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1136
1137                 $command = basename($trace[0]['file']);
1138
1139                 Process::deleteInactive();
1140
1141                 Process::insert($command);
1142         }
1143
1144         /**
1145          * Remove the active process from the "process" table
1146          *
1147          * @brief Remove the active process from the "process" table
1148          * @return bool
1149          */
1150         public static function endProcess()
1151         {
1152                 return Process::deleteByPid();
1153         }
1154
1155         /**
1156          * Set the flag if some job is waiting
1157          *
1158          * @brief Set the flag if some job is waiting
1159          * @param boolean $jobs Is there a waiting job?
1160          */
1161         public static function IPCSetJobState($jobs)
1162         {
1163                 dba::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1164         }
1165
1166         /**
1167          * Checks if some worker job waits to be executed
1168          *
1169          * @brief Checks if some worker job waits to be executed
1170          * @return bool
1171          */
1172         public static function IPCJobsExists()
1173         {
1174                 $row = dba::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1175
1176                 // When we don't have a row, no job is running
1177                 if (!DBM::is_result($row)) {
1178                         return false;
1179                 }
1180
1181                 return (bool)$row['jobs'];
1182         }
1183 }