include/poller.php

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