src/Core/Worker.php

   1 <?php
   2 /**
   3  * @file src/Core/Worker.php
   4  */
   5 namespace Friendica\Core;
   6
   7 use Friendica\BaseObject;
   8 use Friendica\Database\DBA;
   9 use Friendica\Model\Process;
  10 use Friendica\Util\DateTimeFormat;
  11 use Friendica\Util\Network;
  12
  13 /**
  14  * @file src/Core/Worker.php
  15  *
  16  * @brief Contains the class for the worker background job processing
  17  */
  18
  19 /**
  20  * @brief Worker methods
  21  */
  22 class Worker
  23 {
  24         private static $up_start;
  25         private static $db_duration;
  26         private static $last_update;
  27         private static $lock_duration;
  28
  29         /**
  30          * @brief Processes the tasks that are in the workerqueue table
  31          *
  32          * @param boolean $run_cron Should the cron processes be executed?
  33          * @return void
  34          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  35          */
  36         public static function processQueue($run_cron = true)
  37         {
  38                 $a = \get_app();
  39
  40                 self::$up_start = microtime(true);
  41
  42                 // At first check the maximum load. We shouldn't continue with a high load
  43                 if ($a->isMaxLoadReached()) {
  44                         Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
  45                         return;
  46                 }
  47
  48                 // We now start the process. This is done after the load check since this could increase the load.
  49                 self::startProcess();
  50
  51                 // Kill stale processes every 5 minutes
  52                 $last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
  53                 if (time() > ($last_cleanup + 300)) {
  54                         Config::set('system', 'worker_last_cleaned', time());
  55                         self::killStaleWorkers();
  56                 }
  57
  58                 // Count active workers and compare them with a maximum value that depends on the load
  59                 if (self::tooMuchWorkers()) {
  60                         Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
  61                         return;
  62                 }
  63
  64                 // Do we have too few memory?
  65                 if ($a->isMinMemoryReached()) {
  66                         Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
  67                         return;
  68                 }
  69
  70                 // Possibly there are too much database connections
  71                 if (self::maxConnectionsReached()) {
  72                         Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
  73                         return;
  74                 }
  75
  76                 // Possibly there are too much database processes that block the system
  77                 if ($a->isMaxProcessesReached()) {
  78                         Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
  79                         return;
  80                 }
  81
  82                 // Now we start additional cron processes if we should do so
  83                 if ($run_cron) {
  84                         self::runCron();
  85                 }
  86
  87                 $starttime = time();
  88
  89                 // We fetch the next queue entry that is about to be executed
  90                 while ($r = self::workerProcess($passing_slow)) {
  91                         // When we are processing jobs with a lower priority, we don't refetch new jobs
  92                         // Otherwise fast jobs could wait behind slow ones and could be blocked.
  93                         $refetched = $passing_slow;
  94
  95                         foreach ($r as $entry) {
  96                                 // Assure that the priority is an integer value
  97                                 $entry['priority'] = (int)$entry['priority'];
  98
  99                                 // The work will be done
 100                                 if (!self::execute($entry)) {
 101                                         Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 102                                         return;
 103                                 }
 104
 105                                 // If possible we will fetch new jobs for this worker
 106                                 if (!$refetched && Lock::acquire('worker_process', 0)) {
 107                                         $stamp = (float)microtime(true);
 108                                         $refetched = self::findWorkerProcesses($passing_slow);
 109                                         self::$db_duration += (microtime(true) - $stamp);
 110                                         Lock::release('worker_process');
 111                                 }
 112                         }
 113
 114                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 115                         if (Lock::acquire('worker', 0)) {
 116                                 $stamp = (float)microtime(true);
 117                                 // Count active workers and compare them with a maximum value that depends on the load
 118                                 if (self::tooMuchWorkers()) {
 119                                         Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 120                                         Lock::release('worker');
 121                                         return;
 122                                 }
 123
 124                                 // Check free memory
 125                                 if ($a->isMinMemoryReached()) {
 126                                         Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 127                                         Lock::release('worker');
 128                                         return;
 129                                 }
 130                                 Lock::release('worker');
 131                                 self::$db_duration += (microtime(true) - $stamp);
 132                         }
 133
 134                         // Quit the worker once every 5 minutes
 135                         if (time() > ($starttime + 300)) {
 136                                 Logger::log('Process lifetime reached, quitting.', Logger::DEBUG);
 137                                 return;
 138                         }
 139                 }
 140
 141                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 142                 if (Config::get('system', 'worker_daemon_mode', false)) {
 143                         self::IPCSetJobState(false);
 144                 }
 145                 Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
 146         }
 147
 148         /**
 149          * @brief Returns the number of deferred entries in the worker queue
 150          *
 151          * @return integer Number of deferred entries in the worker queue
 152          * @throws \Exception
 153          */
 154         private static function deferredEntries()
 155         {
 156                 return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` > ?",
 157                         DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
 158         }
 159
 160         /**
 161          * @brief Returns the number of non executed entries in the worker queue
 162          *
 163          * @return integer Number of non executed entries in the worker queue
 164          * @throws \Exception
 165          */
 166         private static function totalEntries()
 167         {
 168                 return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` < ?",
 169                         DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
 170         }
 171
 172         /**
 173          * @brief Returns the highest priority in the worker queue that isn't executed
 174          *
 175          * @return integer Number of active worker processes
 176          * @throws \Exception
 177          */
 178         private static function highestPriority()
 179         {
 180                 $condition = ["`executed` <= ? AND NOT `done` AND `next_try` < ?", DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
 181                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 182                 if (DBA::isResult($workerqueue)) {
 183                         return $workerqueue["priority"];
 184                 } else {
 185                         return 0;
 186                 }
 187         }
 188
 189         /**
 190          * @brief Returns if a process with the given priority is running
 191          *
 192          * @param integer $priority The priority that should be checked
 193          *
 194          * @return integer Is there a process running with that priority?
 195          * @throws \Exception
 196          */
 197         private static function processWithPriorityActive($priority)
 198         {
 199                 $condition = ["`priority` <= ? AND `executed` > ? AND NOT `done` AND `next_try` < ?",
 200                         $priority, DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
 201                 return DBA::exists('workerqueue', $condition);
 202         }
 203
 204         /**
 205          * @brief Execute a worker entry
 206          *
 207          * @param array $queue Workerqueue entry
 208          *
 209          * @return boolean "true" if further processing should be stopped
 210          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 211          */
 212         public static function execute($queue)
 213         {
 214                 $a = \get_app();
 215
 216                 $mypid = getmypid();
 217
 218                 // Quit when in maintenance
 219                 if (Config::get('system', 'maintenance', false, true)) {
 220                         Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 221                         return false;
 222                 }
 223
 224                 // Constantly check the number of parallel database processes
 225                 if ($a->isMaxProcessesReached()) {
 226                         Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 227                         return false;
 228                 }
 229
 230                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 231                 if (self::maxConnectionsReached()) {
 232                         Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 233                         return false;
 234                 }
 235
 236                 $argv = json_decode($queue["parameter"], true);
 237
 238                 // Check for existance and validity of the include file
 239                 $include = $argv[0];
 240
 241                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 242                         // We constantly update the "executed" date every minute to avoid being killed too soon
 243                         if (!isset(self::$last_update)) {
 244                                 self::$last_update = strtotime($queue["executed"]);
 245                         }
 246
 247                         $age = (time() - self::$last_update) / 60;
 248                         self::$last_update = time();
 249
 250                         if ($age > 1) {
 251                                 $stamp = (float)microtime(true);
 252                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 253                                 self::$db_duration += (microtime(true) - $stamp);
 254                         }
 255
 256                         array_shift($argv);
 257
 258                         self::execFunction($queue, $include, $argv, true);
 259
 260                         $stamp = (float)microtime(true);
 261
 262                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 263                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 264                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 265                         }
 266                         self::$db_duration = (microtime(true) - $stamp);
 267
 268                         return true;
 269                 }
 270
 271                 // The script could be provided as full path or only with the function name
 272                 if ($include == basename($include)) {
 273                         $include = "include/".$include.".php";
 274                 }
 275
 276                 if (!validate_include($include)) {
 277                         Logger::log("Include file ".$argv[0]." is not valid!");
 278                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 279                         return true;
 280                 }
 281
 282                 require_once $include;
 283
 284                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 285
 286                 if (function_exists($funcname)) {
 287                         // We constantly update the "executed" date every minute to avoid being killed too soon
 288                         if (!isset(self::$last_update)) {
 289                                 self::$last_update = strtotime($queue["executed"]);
 290                         }
 291
 292                         $age = (time() - self::$last_update) / 60;
 293                         self::$last_update = time();
 294
 295                         if ($age > 1) {
 296                                 $stamp = (float)microtime(true);
 297                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 298                                 self::$db_duration += (microtime(true) - $stamp);
 299                         }
 300
 301                         self::execFunction($queue, $funcname, $argv, false);
 302
 303                         $stamp = (float)microtime(true);
 304                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 305                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 306                         }
 307                         self::$db_duration = (microtime(true) - $stamp);
 308                 } else {
 309                         Logger::log("Function ".$funcname." does not exist");
 310                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 311                 }
 312
 313                 return true;
 314         }
 315
 316         /**
 317          * @brief Execute a function from the queue
 318          *
 319          * @param array   $queue       Workerqueue entry
 320          * @param string  $funcname    name of the function
 321          * @param array   $argv        Array of values to be passed to the function
 322          * @param boolean $method_call boolean
 323          * @return void
 324          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 325          */
 326         private static function execFunction($queue, $funcname, $argv, $method_call)
 327         {
 328                 $a = \get_app();
 329
 330                 $mypid = getmypid();
 331
 332                 $argc = count($argv);
 333
 334                 $new_process_id = System::processID("wrk");
 335
 336                 Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
 337
 338                 $stamp = (float)microtime(true);
 339
 340                 // We use the callstack here to analyze the performance of executed worker entries.
 341                 // For this reason the variables have to be initialized.
 342                 if (Config::get("system", "profiler")) {
 343                         $a->performance["start"] = microtime(true);
 344                         $a->performance["database"] = 0;
 345                         $a->performance["database_write"] = 0;
 346                         $a->performance["cache"] = 0;
 347                         $a->performance["cache_write"] = 0;
 348                         $a->performance["network"] = 0;
 349                         $a->performance["file"] = 0;
 350                         $a->performance["rendering"] = 0;
 351                         $a->performance["parser"] = 0;
 352                         $a->performance["marktime"] = 0;
 353                         $a->performance["markstart"] = microtime(true);
 354                         $a->callstack = [];
 355                 }
 356
 357                 // For better logging create a new process id for every worker call
 358                 // But preserve the old one for the worker
 359                 $old_process_id = $a->process_id;
 360                 $a->process_id = $new_process_id;
 361                 $a->queue = $queue;
 362
 363                 $up_duration = number_format(microtime(true) - self::$up_start, 3);
 364
 365                 // Reset global data to avoid interferences
 366                 unset($_SESSION);
 367
 368                 if ($method_call) {
 369                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 370                 } else {
 371                         $funcname($argv, $argc);
 372                 }
 373
 374                 $a->process_id = $old_process_id;
 375                 unset($a->queue);
 376
 377                 $duration = (microtime(true) - $stamp);
 378
 379                 self::$up_start = microtime(true);
 380
 381                 /* With these values we can analyze how effective the worker is.
 382                  * The database and rest time should be low since this is the unproductive time.
 383                  * The execution time is the productive time.
 384                  * By changing parameters like the maximum number of workers we can check the effectivness.
 385                 */
 386                 Logger::log(
 387                         'DB: '.number_format(self::$db_duration, 2).
 388                         ' - Lock: '.number_format(self::$lock_duration, 2).
 389                         ' - Rest: '.number_format($up_duration - self::$db_duration - self::$lock_duration, 2).
 390                         ' - Execution: '.number_format($duration, 2),
 391                         Logger::DEBUG
 392                 );
 393
 394                 self::$lock_duration = 0;
 395
 396                 if ($duration > 3600) {
 397                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", Logger::DEBUG);
 398                 } elseif ($duration > 600) {
 399                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", Logger::DEBUG);
 400                 } elseif ($duration > 300) {
 401                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", Logger::DEBUG);
 402                 } elseif ($duration > 120) {
 403                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", Logger::DEBUG);
 404                 }
 405
 406                 Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds. Process PID: ".$new_process_id);
 407
 408                 // Write down the performance values into the log
 409                 if (Config::get("system", "profiler")) {
 410                         $duration = microtime(true)-$a->performance["start"];
 411
 412                         $o = '';
 413                         if (Config::get("rendertime", "callstack")) {
 414                                 if (isset($a->callstack["database"])) {
 415                                         $o .= "\nDatabase Read:\n";
 416                                         foreach ($a->callstack["database"] 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["database_write"])) {
 424                                         $o .= "\nDatabase Write:\n";
 425                                         foreach ($a->callstack["database_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["dache"])) {
 433                                         $o .= "\nCache Read:\n";
 434                                         foreach ($a->callstack["dache"] as $func => $time) {
 435                                                 $time = round($time, 3);
 436                                                 if ($time > 0) {
 437                                                         $o .= $func.": ".$time."\n";
 438                                                 }
 439                                         }
 440                                 }
 441                                 if (isset($a->callstack["dache_write"])) {
 442                                         $o .= "\nCache Write:\n";
 443                                         foreach ($a->callstack["dache_write"] as $func => $time) {
 444                                                 $time = round($time, 3);
 445                                                 if ($time > 0) {
 446                                                         $o .= $func.": ".$time."\n";
 447                                                 }
 448                                         }
 449                                 }
 450                                 if (isset($a->callstack["network"])) {
 451                                         $o .= "\nNetwork:\n";
 452                                         foreach ($a->callstack["network"] as $func => $time) {
 453                                                 $time = round($time, 3);
 454                                                 if ($time > 0) {
 455                                                         $o .= $func.": ".$time."\n";
 456                                                 }
 457                                         }
 458                                 }
 459                         }
 460
 461                         Logger::log(
 462                                 "ID ".$queue["id"].": ".$funcname.": ".sprintf(
 463                                         "DB: %s/%s, Cache: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
 464                                         number_format($a->performance["database"] - $a->performance["database_write"], 2),
 465                                         number_format($a->performance["database_write"], 2),
 466                                         number_format($a->performance["cache"], 2),
 467                                         number_format($a->performance["cache_write"], 2),
 468                                         number_format($a->performance["network"], 2),
 469                                         number_format($a->performance["file"], 2),
 470                                         number_format($duration - ($a->performance["database"]
 471                                                 + $a->performance["cache"] + $a->performance["cache_write"]
 472                                                 + $a->performance["network"] + $a->performance["file"]), 2),
 473                                         number_format($duration, 2)
 474                                 ),
 475                                 Logger::DEBUG
 476                         );
 477                 }
 478
 479                 $cooldown = Config::get("system", "worker_cooldown", 0);
 480
 481                 if ($cooldown > 0) {
 482                         Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 483                         sleep($cooldown);
 484                 }
 485         }
 486
 487         /**
 488          * @brief Checks if the number of database connections has reached a critical limit.
 489          *
 490          * @return bool Are more than 3/4 of the maximum connections used?
 491          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 492          */
 493         private static function maxConnectionsReached()
 494         {
 495                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 496                 $max = Config::get("system", "max_connections");
 497
 498                 // Fetch the percentage level where the worker will get active
 499                 $maxlevel = Config::get("system", "max_connections_level", 75);
 500
 501                 if ($max == 0) {
 502                         // the maximum number of possible user connections can be a system variable
 503                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 504                         if (DBA::isResult($r)) {
 505                                 $max = $r["Value"];
 506                         }
 507                         // Or it can be granted. This overrides the system variable
 508                         $r = DBA::p('SHOW GRANTS');
 509                         while ($grants = DBA::fetch($r)) {
 510                                 $grant = array_pop($grants);
 511                                 if (stristr($grant, "GRANT USAGE ON")) {
 512                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 513                                                 $max = $match[1];
 514                                         }
 515                                 }
 516                         }
 517                         DBA::close($r);
 518                 }
 519
 520                 // If $max is set we will use the processlist to determine the current number of connections
 521                 // The processlist only shows entries of the current user
 522                 if ($max != 0) {
 523                         $r = DBA::p('SHOW PROCESSLIST');
 524                         $used = DBA::numRows($r);
 525                         DBA::close($r);
 526
 527                         Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 528
 529                         $level = ($used / $max) * 100;
 530
 531                         if ($level >= $maxlevel) {
 532                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 533                                 return true;
 534                         }
 535                 }
 536
 537                 // We will now check for the system values.
 538                 // This limit could be reached although the user limits are fine.
 539                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 540                 if (!DBA::isResult($r)) {
 541                         return false;
 542                 }
 543                 $max = intval($r["Value"]);
 544                 if ($max == 0) {
 545                         return false;
 546                 }
 547                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 548                 if (!DBA::isResult($r)) {
 549                         return false;
 550                 }
 551                 $used = intval($r["Value"]);
 552                 if ($used == 0) {
 553                         return false;
 554                 }
 555                 Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 556
 557                 $level = $used / $max * 100;
 558
 559                 if ($level < $maxlevel) {
 560                         return false;
 561                 }
 562                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 563                 return true;
 564         }
 565
 566         /**
 567          * @brief fix the queue entry if the worker process died
 568          * @return void
 569          * @throws \Exception
 570          */
 571         private static function killStaleWorkers()
 572         {
 573                 $entries = DBA::select(
 574                         'workerqueue',
 575                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 576                         ['`executed` > ? AND NOT `done` AND `pid` != 0', DBA::NULL_DATETIME],
 577                         ['order' => ['priority', 'created']]
 578                 );
 579
 580                 while ($entry = DBA::fetch($entries)) {
 581                         if (!posix_kill($entry["pid"], 0)) {
 582                                 DBA::update(
 583                                         'workerqueue',
 584                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 585                                         ['id' => $entry["id"]]
 586                                 );
 587                         } else {
 588                                 // Kill long running processes
 589                                 // Check if the priority is in a valid range
 590                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 591                                         $entry["priority"] = PRIORITY_MEDIUM;
 592                                 }
 593
 594                                 // Define the maximum durations
 595                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 596                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 597
 598                                 $argv = json_decode($entry["parameter"], true);
 599                                 $argv[0] = basename($argv[0]);
 600
 601                                 // How long is the process already running?
 602                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 603                                 if ($duration > $max_duration) {
 604                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 605                                         posix_kill($entry["pid"], SIGTERM);
 606
 607                                         // We killed the stale process.
 608                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 609                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 610                                         $new_priority = $entry["priority"];
 611                                         if ($entry["priority"] == PRIORITY_HIGH) {
 612                                                 $new_priority = PRIORITY_MEDIUM;
 613                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 614                                                 $new_priority = PRIORITY_LOW;
 615                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 616                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 617                                         }
 618                                         DBA::update(
 619                                                 'workerqueue',
 620                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 621                                                 ['id' => $entry["id"]]
 622                                         );
 623                                 } else {
 624                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 625                                 }
 626                         }
 627                 }
 628         }
 629
 630         /**
 631          * @brief Checks if the number of active workers exceeds the given limits
 632          *
 633          * @return bool Are there too much workers running?
 634          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 635          */
 636         public static function tooMuchWorkers()
 637         {
 638                 $queues = Config::get("system", "worker_queues", 4);
 639
 640                 $maxqueues = $queues;
 641
 642                 $active = self::activeWorkers();
 643
 644                 // Decrease the number of workers at higher load
 645                 $load = System::currentLoad();
 646                 if ($load) {
 647                         $maxsysload = intval(Config::get("system", "maxloadavg", 50));
 648
 649                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 650                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 651                          * For some environments, this rapid decrease is not needed.
 652                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 653                          */
 654                         $exponent = intval(Config::get('system', 'worker_load_exponent', 3));
 655                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 656                         $queues = intval(ceil($slope * $maxqueues));
 657
 658                         $processlist = '';
 659
 660                         if (Config::get('system', 'worker_debug')) {
 661                                 // Create a list of queue entries grouped by their priority
 662                                 $listitem = [];
 663
 664                                 // Adding all processes with no workerqueue entry
 665                                 $processes = DBA::p(
 666                                         "SELECT COUNT(*) AS `running` FROM `process` WHERE NOT EXISTS
 667                                                         (SELECT id FROM `workerqueue`
 668                                                         WHERE `workerqueue`.`pid` = `process`.`pid` AND NOT `done` AND `pid` != ?)",
 669                                         getmypid()
 670                                 );
 671
 672                                 if ($process = DBA::fetch($processes)) {
 673                                         $listitem[0] = "0:".$process["running"];
 674                                 }
 675                                 DBA::close($processes);
 676
 677                                 // Now adding all processes with workerqueue entries
 678                                 $entries = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` AND `next_try` < ? GROUP BY `priority`", DateTimeFormat::utcNow());
 679                                 while ($entry = DBA::fetch($entries)) {
 680                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `next_try` < ? AND `priority` = ?",
 681                                                 DateTimeFormat::utcNow(), $entry["priority"]);
 682                                         if ($process = DBA::fetch($processes)) {
 683                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 684                                         }
 685                                         DBA::close($processes);
 686                                 }
 687                                 DBA::close($entries);
 688
 689                                 $intervals = [1, 10, 60];
 690                                 $jobs_per_minute = [];
 691                                 foreach ($intervals as $interval) {
 692                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ".intval($interval)." MINUTE");
 693                                         if ($job = DBA::fetch($jobs)) {
 694                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 695                                         }
 696                                         DBA::close($jobs);
 697                                 }
 698                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute).' ('.implode(', ', $listitem).')';
 699                         }
 700
 701                         $entries = self::totalEntries();
 702                         $deferred = self::deferredEntries();
 703
 704                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($active >= $queues)) {
 705                                 $top_priority = self::highestPriority();
 706                                 $high_running = self::processWithPriorityActive($top_priority);
 707
 708                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 709                                         Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 710                                         $queues = $active + 1;
 711                                 }
 712                         }
 713
 714                         Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $entries . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 715
 716                         // Are there fewer workers running as possible? Then fork a new one.
 717                         if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && ($entries > 1)) {
 718                                 Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 719                                 if (Config::get('system', 'worker_daemon_mode', false)) {
 720                                         self::IPCSetJobState(true);
 721                                 } else {
 722                                         self::spawnWorker();
 723                                 }
 724                         }
 725                 }
 726
 727                 // if there are too much worker, we don't spawn a new one.
 728                 if (Config::get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 729                         self::IPCSetJobState(false);
 730                 }
 731
 732                 return $active > $queues;
 733         }
 734
 735         /**
 736          * @brief Returns the number of active worker processes
 737          *
 738          * @return integer Number of active worker processes
 739          * @throws \Exception
 740          */
 741         private static function activeWorkers()
 742         {
 743                 return DBA::count('process', ['command' => 'Worker.php']);
 744         }
 745
 746         /**
 747          * @brief Check if we should pass some slow processes
 748          *
 749          * When the active processes of the highest priority are using more than 2/3
 750          * of all processes, we let pass slower processes.
 751          *
 752          * @param string $highest_priority Returns the currently highest priority
 753          * @return bool We let pass a slower process than $highest_priority
 754          * @throws \Exception
 755          */
 756         private static function passingSlow(&$highest_priority)
 757         {
 758                 $highest_priority = 0;
 759
 760                 $r = DBA::p(
 761                         "SELECT `priority`
 762                                 FROM `process`
 763                                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done`"
 764                 );
 765
 766                 // No active processes at all? Fine
 767                 if (!DBA::isResult($r)) {
 768                         return false;
 769                 }
 770                 $priorities = [];
 771                 while ($line = DBA::fetch($r)) {
 772                         $priorities[] = $line["priority"];
 773                 }
 774                 DBA::close($r);
 775
 776                 // Should not happen
 777                 if (count($priorities) == 0) {
 778                         return false;
 779                 }
 780                 $highest_priority = min($priorities);
 781
 782                 // The highest process is already the slowest one?
 783                 // Then we quit
 784                 if ($highest_priority == PRIORITY_NEGLIGIBLE) {
 785                         return false;
 786                 }
 787                 $high = 0;
 788                 foreach ($priorities as $priority) {
 789                         if ($priority == $highest_priority) {
 790                                 ++$high;
 791                         }
 792                 }
 793                 Logger::log("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, Logger::DEBUG);
 794                 $passing_slow = (($high/count($priorities)) > (2/3));
 795
 796                 if ($passing_slow) {
 797                         Logger::log("Passing slower processes than priority ".$highest_priority, Logger::DEBUG);
 798                 }
 799                 return $passing_slow;
 800         }
 801
 802         /**
 803          * @brief Find and claim the next worker process for us
 804          *
 805          * @param boolean $passing_slow Returns if we had passed low priority processes
 806          * @return boolean Have we found something?
 807          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 808          */
 809         private static function findWorkerProcesses(&$passing_slow)
 810         {
 811                 $mypid = getmypid();
 812
 813                 // Check if we should pass some low priority process
 814                 $highest_priority = 0;
 815                 $found = false;
 816                 $passing_slow = false;
 817
 818                 // The higher the number of parallel workers, the more we prefetch to prevent concurring access
 819                 // We decrease the limit with the number of entries left in the queue
 820                 $worker_queues = Config::get("system", "worker_queues", 4);
 821                 $queue_length = Config::get('system', 'worker_fetch_limit', 1);
 822                 $lower_job_limit = $worker_queues * $queue_length * 2;
 823                 $jobs = self::totalEntries();
 824                 $deferred = self::deferredEntries();
 825
 826                 // Now do some magic
 827                 $exponent = 2;
 828                 $slope = $queue_length / pow($lower_job_limit, $exponent);
 829                 $limit = min($queue_length, ceil($slope * pow($jobs, $exponent)));
 830
 831                 Logger::log('Deferred: ' . $deferred . ' - Total: ' . $jobs . ' - Maximum: ' . $queue_length . ' - jobs per queue: ' . $limit, Logger::DEBUG);
 832                 $ids = [];
 833                 if (self::passingSlow($highest_priority)) {
 834                         // Are there waiting processes with a higher priority than the currently highest?
 835                         $result = DBA::select(
 836                                 'workerqueue',
 837                                 ['id'],
 838                                 ["`executed` <= ? AND `priority` < ? AND NOT `done` AND `next_try` < ?",
 839                                 DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
 840                                 ['limit' => $limit, 'order' => ['priority', 'created']]
 841                         );
 842
 843                         while ($id = DBA::fetch($result)) {
 844                                 $ids[] = $id["id"];
 845                         }
 846                         DBA::close($result);
 847
 848                         $found = (count($ids) > 0);
 849
 850                         if (!$found) {
 851                                 // Give slower processes some processing time
 852                                 $result = DBA::select(
 853                                         'workerqueue',
 854                                         ['id'],
 855                                         ["`executed` <= ? AND `priority` > ? AND NOT `done` AND `next_try` < ?",
 856                                         DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
 857                                         ['limit' => $limit, 'order' => ['priority', 'created']]
 858                                 );
 859
 860                                 while ($id = DBA::fetch($result)) {
 861                                         $ids[] = $id["id"];
 862                                 }
 863                                 DBA::close($result);
 864
 865                                 $found = (count($ids) > 0);
 866                                 $passing_slow = $found;
 867                         }
 868                 }
 869
 870                 // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 871                 if (!$found) {
 872                         $result = DBA::select(
 873                                 'workerqueue',
 874                                 ['id'],
 875                                 ["`executed` <= ? AND NOT `done` AND `next_try` < ?",
 876                                 DBA::NULL_DATETIME, DateTimeFormat::utcNow()],
 877                                 ['limit' => $limit, 'order' => ['priority', 'created']]
 878                         );
 879
 880                         while ($id = DBA::fetch($result)) {
 881                                 $ids[] = $id["id"];
 882                         }
 883                         DBA::close($result);
 884
 885                         $found = (count($ids) > 0);
 886                 }
 887
 888                 if ($found) {
 889                         $condition = "`id` IN (".substr(str_repeat("?, ", count($ids)), 0, -2).") AND `pid` = 0 AND NOT `done`";
 890                         array_unshift($ids, $condition);
 891                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $ids);
 892                 }
 893
 894                 return $found;
 895         }
 896
 897         /**
 898          * @brief Returns the next worker process
 899          *
 900          * @param boolean $passing_slow Returns if we had passed low priority processes
 901          * @return string SQL statement
 902          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 903          */
 904         public static function workerProcess(&$passing_slow)
 905         {
 906                 $stamp = (float)microtime(true);
 907
 908                 // There can already be jobs for us in the queue.
 909                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 910                 if (DBA::isResult($r)) {
 911                         self::$db_duration += (microtime(true) - $stamp);
 912                         return DBA::toArray($r);
 913                 }
 914                 DBA::close($r);
 915
 916                 $stamp = (float)microtime(true);
 917                 if (!Lock::acquire('worker_process')) {
 918                         return false;
 919                 }
 920                 self::$lock_duration = (microtime(true) - $stamp);
 921
 922                 $stamp = (float)microtime(true);
 923                 $found = self::findWorkerProcesses($passing_slow);
 924                 self::$db_duration += (microtime(true) - $stamp);
 925
 926                 Lock::release('worker_process');
 927
 928                 if ($found) {
 929                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 930                         return DBA::toArray($r);
 931                 }
 932                 return false;
 933         }
 934
 935         /**
 936          * @brief Removes a workerqueue entry from the current process
 937          * @return void
 938          * @throws \Exception
 939          */
 940         public static function unclaimProcess()
 941         {
 942                 $mypid = getmypid();
 943
 944                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 945         }
 946
 947         /**
 948          * @brief Call the front end worker
 949          * @return void
 950          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 951          */
 952         public static function callWorker()
 953         {
 954                 if (!Config::get("system", "frontend_worker")) {
 955                         return;
 956                 }
 957
 958                 $url = System::baseUrl()."/worker";
 959                 Network::fetchUrl($url, false, $redirects, 1);
 960         }
 961
 962         /**
 963          * @brief Call the front end worker if there aren't any active
 964          * @return void
 965          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 966          */
 967         public static function executeIfIdle()
 968         {
 969                 if (!Config::get("system", "frontend_worker")) {
 970                         return;
 971                 }
 972
 973                 // Do we have "proc_open"? Then we can fork the worker
 974                 if (function_exists("proc_open")) {
 975                         // When was the last time that we called the worker?
 976                         // Less than one minute? Then we quit
 977                         if ((time() - Config::get("system", "worker_started")) < 60) {
 978                                 return;
 979                         }
 980
 981                         Config::set("system", "worker_started", time());
 982
 983                         // Do we have enough running workers? Then we quit here.
 984                         if (self::tooMuchWorkers()) {
 985                                 // Cleaning dead processes
 986                                 self::killStaleWorkers();
 987                                 Process::deleteInactive();
 988
 989                                 return;
 990                         }
 991
 992                         self::runCron();
 993
 994                         Logger::log('Call worker', Logger::DEBUG);
 995                         self::spawnWorker();
 996                         return;
 997                 }
 998
 999                 // We cannot execute background processes.
1000                 // We now run the processes from the frontend.
1001                 // This won't work with long running processes.
1002                 self::runCron();
1003
1004                 self::clearProcesses();
1005
1006                 $workers = self::activeWorkers();
1007
1008                 if ($workers == 0) {
1009                         self::callWorker();
1010                 }
1011         }
1012
1013         /**
1014          * @brief Removes long running worker processes
1015          * @return void
1016          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1017          */
1018         public static function clearProcesses()
1019         {
1020                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
1021
1022                 /// @todo We should clean up the corresponding workerqueue entries as well
1023                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1024                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1025                 DBA::delete('process', $condition);
1026         }
1027
1028         /**
1029          * @brief Runs the cron processes
1030          * @return void
1031          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1032          */
1033         private static function runCron()
1034         {
1035                 Logger::log('Add cron entries', Logger::DEBUG);
1036
1037                 // Check for spooled items
1038                 self::add(PRIORITY_HIGH, "SpoolPost");
1039
1040                 // Run the cron job that calls all other jobs
1041                 self::add(PRIORITY_MEDIUM, "Cron");
1042
1043                 // Cleaning dead processes
1044                 self::killStaleWorkers();
1045         }
1046
1047         /**
1048          * @brief Spawns a new worker
1049          * @param bool $do_cron
1050          * @return void
1051          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1052          */
1053         public static function spawnWorker($do_cron = false)
1054         {
1055                 $command = 'bin/worker.php';
1056
1057                 $args = ['no_cron' => !$do_cron];
1058
1059                 get_app()->proc_run($command, $args);
1060
1061                 // after spawning we have to remove the flag.
1062                 if (Config::get('system', 'worker_daemon_mode', false)) {
1063                         self::IPCSetJobState(false);
1064                 }
1065         }
1066
1067         /**
1068          * @brief Adds tasks to the worker queue
1069          *
1070          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1071          *
1072          * next args are passed as $cmd command line
1073          * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
1074          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1075          *
1076          * @return boolean "false" if proc_run couldn't be executed
1077          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1078          * @note $cmd and string args are surrounded with ""
1079          *
1080          * @hooks 'proc_run'
1081          *    array $arr
1082          *
1083          */
1084         public static function add($cmd)
1085         {
1086                 $args = func_get_args();
1087
1088                 if (!count($args)) {
1089                         return false;
1090                 }
1091
1092                 $arr = ['args' => $args, 'run_cmd' => true];
1093
1094                 Hook::callAll("proc_run", $arr);
1095                 if (!$arr['run_cmd'] || !count($args)) {
1096                         return true;
1097                 }
1098
1099                 $priority = PRIORITY_MEDIUM;
1100                 $dont_fork = Config::get("system", "worker_dont_fork", false);
1101                 $created = DateTimeFormat::utcNow();
1102
1103                 $run_parameter = array_shift($args);
1104
1105                 if (is_int($run_parameter)) {
1106                         $priority = $run_parameter;
1107                 } elseif (is_array($run_parameter)) {
1108                         if (isset($run_parameter['priority'])) {
1109                                 $priority = $run_parameter['priority'];
1110                         }
1111                         if (isset($run_parameter['created'])) {
1112                                 $created = $run_parameter['created'];
1113                         }
1114                         if (isset($run_parameter['dont_fork'])) {
1115                                 $dont_fork = $run_parameter['dont_fork'];
1116                         }
1117                 }
1118
1119                 $parameters = json_encode($args);
1120                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1121
1122                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1123                 if (DBA::errorNo() != 0) {
1124                         return false;
1125                 }
1126
1127                 if (!$found) {
1128                         DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1129                 }
1130
1131                 // Should we quit and wait for the worker to be called as a cronjob?
1132                 if ($dont_fork) {
1133                         return true;
1134                 }
1135
1136                 // If there is a lock then we don't have to check for too much worker
1137                 if (!Lock::acquire('worker', 0)) {
1138                         return true;
1139                 }
1140
1141                 // If there are already enough workers running, don't fork another one
1142                 $quit = self::tooMuchWorkers();
1143                 Lock::release('worker');
1144
1145                 if ($quit) {
1146                         return true;
1147                 }
1148
1149                 // We tell the daemon that a new job entry exists
1150                 if (Config::get('system', 'worker_daemon_mode', false)) {
1151                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1152                         return true;
1153                 }
1154
1155                 // Now call the worker to execute the jobs that we just added to the queue
1156                 self::spawnWorker();
1157
1158                 return true;
1159         }
1160
1161         /**
1162          * Defers the current worker entry
1163          */
1164         public static function defer()
1165         {
1166                 if (empty(BaseObject::getApp()->queue)) {
1167                         return;
1168                 }
1169
1170                 $queue = BaseObject::getApp()->queue;
1171
1172                 $retrial = $queue['retrial'];
1173                 $id = $queue['id'];
1174
1175                 if ($retrial > 14) {
1176                         Logger::log('Id ' . $id . ' had been tried 14 times. We stop now.', Logger::DEBUG);
1177                         return;
1178                 }
1179
1180                 // Calculate the delay until the next trial
1181                 $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1182                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1183
1184                 Logger::log('Defer execution ' . $retrial . ' of id ' . $id . ' to ' . $next, Logger::DEBUG);
1185
1186                 $fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0];
1187                 DBA::update('workerqueue', $fields, ['id' => $id]);
1188         }
1189
1190         /**
1191          * Log active processes into the "process" table
1192          *
1193          * @brief Log active processes into the "process" table
1194          */
1195         public static function startProcess()
1196         {
1197                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1198
1199                 $command = basename($trace[0]['file']);
1200
1201                 Process::deleteInactive();
1202
1203                 Process::insert($command);
1204         }
1205
1206         /**
1207          * Remove the active process from the "process" table
1208          *
1209          * @brief Remove the active process from the "process" table
1210          * @return bool
1211          * @throws \Exception
1212          */
1213         public static function endProcess()
1214         {
1215                 return Process::deleteByPid();
1216         }
1217
1218         /**
1219          * Set the flag if some job is waiting
1220          *
1221          * @brief Set the flag if some job is waiting
1222          * @param boolean $jobs Is there a waiting job?
1223          * @throws \Exception
1224          */
1225         public static function IPCSetJobState($jobs)
1226         {
1227                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1228         }
1229
1230         /**
1231          * Checks if some worker job waits to be executed
1232          *
1233          * @brief Checks if some worker job waits to be executed
1234          * @return bool
1235          * @throws \Exception
1236          */
1237         public static function IPCJobsExists()
1238         {
1239                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1240
1241                 // When we don't have a row, no job is running
1242                 if (!DBA::isResult($row)) {
1243                         return false;
1244                 }
1245
1246                 return (bool)$row['jobs'];
1247         }
1248 }