include/poller.php

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