include/poller.php

   1 <?php
   2 if (!file_exists("boot.php") AND (sizeof($_SERVER["argv"]) != 0)) {
   3         $directory = dirname($_SERVER["argv"][0]);
   4
   5         if (substr($directory, 0, 1) != "/")
   6                 $directory = $_SERVER["PWD"]."/".$directory;
   7
   8         $directory = realpath($directory."/..");
   9
  10         chdir($directory);
  11 }
  12
  13 use \Friendica\Core\Config;
  14 use \Friendica\Core\PConfig;
  15
  16 require_once("boot.php");
  17
  18 function poller_run($argv, $argc){
  19         global $a, $db;
  20
  21         if(is_null($a)) {
  22                 $a = new App;
  23         }
  24
  25         if(is_null($db)) {
  26                 @include(".htconfig.php");
  27                 require_once("include/dba.php");
  28                 $db = new dba($db_host, $db_user, $db_pass, $db_data);
  29                 unset($db_host, $db_user, $db_pass, $db_data);
  30         };
  31
  32         // Quit when in maintenance
  33         if (get_config('system', 'maintenance', true))
  34                 return;
  35
  36         $a->start_process();
  37
  38         if ($a->max_processes_reached())
  39                 return;
  40
  41         if (poller_max_connections_reached())
  42                 return;
  43
  44         if (App::maxload_reached())
  45                 return;
  46
  47         // Checking the number of workers
  48         if (poller_too_much_workers()) {
  49                 poller_kill_stale_workers();
  50                 return;
  51         }
  52
  53         if(($argc <= 1) OR ($argv[1] != "no_cron")) {
  54                 poller_run_cron();
  55         } else
  56                 // Sleep four seconds before checking for running processes again to avoid having too many workers
  57                 sleep(4);
  58
  59         // Checking number of workers
  60         if (poller_too_much_workers())
  61                 return;
  62
  63         $starttime = time();
  64
  65         while ($r = poller_worker_process()) {
  66
  67                 // Count active workers and compare them with a maximum value that depends on the load
  68                 if (poller_too_much_workers()) {
  69                         return;
  70                 }
  71
  72                 if (!poller_execute($r[0])) {
  73                         return;
  74                 }
  75
  76                 // Quit the poller once every hour
  77                 if (time() > ($starttime + 3600))
  78                         return;
  79         }
  80
  81 }
  82
  83 /**
  84  * @brief Execute a worker entry
  85  *
  86  * @param array $queue Workerqueue entry
  87  *
  88  * @return boolean "true" if further processing should be stopped
  89  */
  90 function poller_execute($queue) {
  91
  92         $a = get_app();
  93
  94         $mypid = getmypid();
  95
  96         $cooldown = Config::get("system", "worker_cooldown", 0);
  97
  98         // Quit when in maintenance
  99         if (get_config('system', 'maintenance', true)) {
 100                 return false;
 101         }
 102
 103         // Constantly check the number of parallel database processes
 104         if ($a->max_processes_reached()) {
 105                 return false;
 106         }
 107
 108         // Constantly check the number of available database connections to let the frontend be accessible at any time
 109         if (poller_max_connections_reached()) {
 110                 return false;
 111         }
 112
 113         $upd = q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `pid` = 0",
 114                 dbesc(datetime_convert()),
 115                 intval($mypid),
 116                 intval($queue["id"]));
 117
 118         if (!$upd) {
 119                 logger("Couldn't update queue entry ".$queue["id"]." - skip this execution", LOGGER_DEBUG);
 120                 q("COMMIT");
 121                 return true;
 122         }
 123
 124         // Assure that there are no tasks executed twice
 125         $id = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
 126         if (!$id) {
 127                 logger("Queue item ".$queue["id"]." vanished - skip this execution", LOGGER_DEBUG);
 128                 q("COMMIT");
 129                 return true;
 130         } elseif ((strtotime($id[0]["executed"]) <= 0) OR ($id[0]["pid"] == 0)) {
 131                 logger("Entry for queue item ".$queue["id"]." wasn't stored - skip this execution", LOGGER_DEBUG);
 132                 q("COMMIT");
 133                 return true;
 134         } elseif ($id[0]["pid"] != $mypid) {
 135                 logger("Queue item ".$queue["id"]." is to be executed by process ".$id[0]["pid"]." and not by me (".$mypid.") - skip this execution", LOGGER_DEBUG);
 136                 q("COMMIT");
 137                 return true;
 138         }
 139         q("COMMIT");
 140
 141         $argv = json_decode($queue["parameter"]);
 142
 143         $argc = count($argv);
 144
 145         // Check for existance and validity of the include file
 146         $include = $argv[0];
 147
 148         if (!validate_include($include)) {
 149                 logger("Include file ".$argv[0]." is not valid!");
 150                 q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
 151                 return true;
 152         }
 153
 154         require_once($include);
 155
 156         $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 157
 158         if (function_exists($funcname)) {
 159                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]);
 160
 161                 // For better logging create a new process id for every worker call
 162                 // But preserve the old one for the worker
 163                 $old_process_id = $a->process_id;
 164                 $a->process_id = uniqid("wrk", true);
 165
 166                 $funcname($argv, $argc);
 167
 168                 $a->process_id = $old_process_id;
 169
 170                 if ($cooldown > 0) {
 171                         logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 172                         sleep($cooldown);
 173                 }
 174
 175                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done");
 176
 177                 q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
 178         } else {
 179                 logger("Function ".$funcname." does not exist");
 180         }
 181
 182         return true;
 183 }
 184
 185 /**
 186  * @brief Checks if the number of database connections has reached a critical limit.
 187  *
 188  * @return bool Are more than 3/4 of the maximum connections used?
 189  */
 190 function poller_max_connections_reached() {
 191
 192         // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 193         $max = get_config("system", "max_connections");
 194
 195         // Fetch the percentage level where the poller will get active
 196         $maxlevel = get_config("system", "max_connections_level");
 197         if ($maxlevel == 0)
 198                 $maxlevel = 75;
 199
 200         if ($max == 0) {
 201                 // the maximum number of possible user connections can be a system variable
 202                 $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 203                 if ($r)
 204                         $max = $r[0]["Value"];
 205
 206                 // Or it can be granted. This overrides the system variable
 207                 $r = q("SHOW GRANTS");
 208                 if ($r)
 209                         foreach ($r AS $grants) {
 210                                 $grant = array_pop($grants);
 211                                 if (stristr($grant, "GRANT USAGE ON"))
 212                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
 213                                                 $max = $match[1];
 214                         }
 215         }
 216
 217         // If $max is set we will use the processlist to determine the current number of connections
 218         // The processlist only shows entries of the current user
 219         if ($max != 0) {
 220                 $r = q("SHOW PROCESSLIST");
 221                 if (!$r)
 222                         return false;
 223
 224                 $used = count($r);
 225
 226                 logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 227
 228                 $level = ($used / $max) * 100;
 229
 230                 if ($level >= $maxlevel) {
 231                         logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 232                         return true;
 233                 }
 234         }
 235
 236         // We will now check for the system values.
 237         // This limit could be reached although the user limits are fine.
 238         $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 239         if (!$r)
 240                 return false;
 241
 242         $max = intval($r[0]["Value"]);
 243         if ($max == 0)
 244                 return false;
 245
 246         $r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 247         if (!$r)
 248                 return false;
 249
 250         $used = intval($r[0]["Value"]);
 251         if ($used == 0)
 252                 return false;
 253
 254         logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 255
 256         $level = $used / $max * 100;
 257
 258         if ($level < $maxlevel)
 259                 return false;
 260
 261         logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 262         return true;
 263 }
 264
 265 /**
 266  * @brief fix the queue entry if the worker process died
 267  *
 268  */
 269 function poller_kill_stale_workers() {
 270         $r = q("SELECT `pid`, `executed`, `priority`, `parameter` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 271
 272         if (!dbm::is_result($r)) {
 273                 // No processing here needed
 274                 return;
 275         }
 276
 277         foreach($r AS $pid)
 278                 if (!posix_kill($pid["pid"], 0))
 279                         q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 280                                 intval($pid["pid"]));
 281                 else {
 282                         // Kill long running processes
 283
 284                         // Check if the priority is in a valid range
 285                         if (!in_array($pid["priority"], array(PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE)))
 286                                 $pid["priority"] = PRIORITY_MEDIUM;
 287
 288                         // Define the maximum durations
 289                         $max_duration_defaults = array(PRIORITY_CRITICAL => 360, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 360);
 290                         $max_duration = $max_duration_defaults[$pid["priority"]];
 291
 292                         $argv = json_decode($pid["parameter"]);
 293                         $argv[0] = basename($argv[0]);
 294
 295                         // How long is the process already running?
 296                         $duration = (time() - strtotime($pid["executed"])) / 60;
 297                         if ($duration > $max_duration) {
 298                                 logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
 299                                 posix_kill($pid["pid"], SIGTERM);
 300
 301                                 // We killed the stale process.
 302                                 // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 303                                 // Additionally we are lowering the priority.
 304                                 q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `created` = '%s',
 305                                                         `priority` = %d, `pid` = 0 WHERE `pid` = %d",
 306                                         dbesc(datetime_convert()),
 307                                         intval(PRIORITY_NEGLIGIBLE),
 308                                         intval($pid["pid"]));
 309                         } else
 310                                 logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
 311                 }
 312 }
 313
 314 /**
 315  * @brief Checks if the number of active workers exceeds the given limits
 316  *
 317  * @return bool Are there too much workers running?
 318  */
 319 function poller_too_much_workers() {
 320
 321
 322         $queues = get_config("system", "worker_queues");
 323
 324         if ($queues == 0)
 325                 $queues = 4;
 326
 327         $maxqueues = $queues;
 328
 329         $active = poller_active_workers();
 330
 331         // Decrease the number of workers at higher load
 332         $load = current_load();
 333         if($load) {
 334                 $maxsysload = intval(get_config('system','maxloadavg'));
 335                 if($maxsysload < 1)
 336                         $maxsysload = 50;
 337
 338                 $maxworkers = $queues;
 339
 340                 // Some magical mathemathics to reduce the workers
 341                 $exponent = 3;
 342                 $slope = $maxworkers / pow($maxsysload, $exponent);
 343                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 344
 345                 $s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00'");
 346                 $entries = $s[0]["total"];
 347
 348                 if (Config::get("system", "worker_fastlane", false) AND ($queues > 0) AND ($entries > 0) AND ($active >= $queues)) {
 349                         $s = q("SELECT `priority` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `priority` LIMIT 1");
 350                         $top_priority = $s[0]["priority"];
 351
 352                         $s = q("SELECT `id` FROM `workerqueue` WHERE `priority` <= %d AND `executed` != '0000-00-00 00:00:00' LIMIT 1",
 353                                 intval($top_priority));
 354                         $high_running = dbm::is_result($s);
 355
 356                         if (!$high_running AND ($top_priority > PRIORITY_UNDEFINED) AND ($top_priority < PRIORITY_NEGLIGIBLE)) {
 357                                 logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
 358                                 $queues = $active + 1;
 359                         }
 360                 }
 361
 362                 // Create a list of queue entries grouped by their priority
 363                 $running = array(PRIORITY_CRITICAL => 0,
 364                                 PRIORITY_HIGH => 0,
 365                                 PRIORITY_MEDIUM => 0,
 366                                 PRIORITY_LOW => 0,
 367                                 PRIORITY_NEGLIGIBLE => 0);
 368
 369                 $r = q("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` GROUP BY `priority`");
 370                 if (dbm::is_result($r))
 371                         foreach ($r AS $process)
 372                                 $running[$process["priority"]] = $process["running"];
 373
 374                 $processlist = "";
 375                 $r = q("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` GROUP BY `priority`");
 376                 if (dbm::is_result($r))
 377                         foreach ($r as $entry) {
 378                                 if ($processlist != "")
 379                                         $processlist .= ", ";
 380                                 $processlist .= $entry["priority"].":".$running[$entry["priority"]]."/".$entry["entries"];
 381                         }
 382
 383                 logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries." (".$processlist.") - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
 384
 385                 // Are there fewer workers running as possible? Then fork a new one.
 386                 if (!get_config("system", "worker_dont_fork") AND ($queues > ($active + 1)) AND ($entries > 1)) {
 387                         logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
 388                         $args = array("php", "include/poller.php", "no_cron");
 389                         $a = get_app();
 390                         $a->proc_run($args);
 391                 }
 392         }
 393
 394         return($active >= $queues);
 395 }
 396
 397 /**
 398  * @brief Returns the number of active poller processes
 399  *
 400  * @return integer Number of active poller processes
 401  */
 402 function poller_active_workers() {
 403         $workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'poller.php'");
 404
 405         return($workers[0]["processes"]);
 406 }
 407
 408 /**
 409  * @brief Check if we should pass some slow processes
 410  *
 411  * When the active processes of the highest priority are using more than 2/3
 412  * of all processes, we let pass slower processes.
 413  *
 414  * @param string $highest_priority Returns the currently highest priority
 415  * @return bool We let pass a slower process than $highest_priority
 416  */
 417 function poller_passing_slow(&$highest_priority) {
 418
 419         $highest_priority = 0;
 420
 421         $r = q("SELECT `priority`
 422                 FROM `process`
 423                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`");
 424
 425         // No active processes at all? Fine
 426         if (!dbm::is_result($r))
 427                 return(false);
 428
 429         $priorities = array();
 430         foreach ($r AS $line)
 431                 $priorities[] = $line["priority"];
 432
 433         // Should not happen
 434         if (count($priorities) == 0)
 435                 return(false);
 436
 437         $highest_priority = min($priorities);
 438
 439         // The highest process is already the slowest one?
 440         // Then we quit
 441         if ($highest_priority == PRIORITY_NEGLIGIBLE)
 442                 return(false);
 443
 444         $high = 0;
 445         foreach ($priorities AS $priority)
 446                 if ($priority == $highest_priority)
 447                         ++$high;
 448
 449         logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
 450         $passing_slow = (($high/count($priorities)) > (2/3));
 451
 452         if ($passing_slow)
 453                 logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
 454
 455         return($passing_slow);
 456 }
 457
 458 /**
 459  * @brief Returns the next worker process
 460  *
 461  * @return string SQL statement
 462  */
 463 function poller_worker_process() {
 464
 465         q("START TRANSACTION;");
 466
 467         // Check if we should pass some low priority process
 468         $highest_priority = 0;
 469
 470         if (poller_passing_slow($highest_priority)) {
 471                 // Are there waiting processes with a higher priority than the currently highest?
 472                 $r = q("SELECT * FROM `workerqueue`
 473                                 WHERE `executed` = '0000-00-00 00:00:00' AND `priority` < %d
 474                                 ORDER BY `priority`, `created` LIMIT 1", dbesc($highest_priority));
 475                 if (dbm::is_result($r))
 476                         return $r;
 477
 478                 // Give slower processes some processing time
 479                 $r = q("SELECT * FROM `workerqueue`
 480                                 WHERE `executed` = '0000-00-00 00:00:00' AND `priority` > %d
 481                                 ORDER BY `priority`, `created` LIMIT 1", dbesc($highest_priority));
 482         }
 483
 484         // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 485         if (($highest_priority == 0) OR !dbm::is_result($r))
 486                 $r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `priority`, `created` LIMIT 1");
 487
 488         return $r;
 489 }
 490
 491 /**
 492  * @brief Call the front end worker
 493  */
 494 function call_worker() {
 495         if (!get_config("system", "frontend_worker")) {
 496                 return;
 497         }
 498
 499         $url = get_app()->get_baseurl()."/worker";
 500         fetch_url($url, false, $redirects, 1);
 501 }
 502
 503 /**
 504  * @brief Call the front end worker if there aren't any active
 505  */
 506 function call_worker_if_idle() {
 507         if (!get_config("system", "frontend_worker")) {
 508                 return;
 509         }
 510
 511         // Do we have "proc_open"? Then we can fork the poller
 512         if (function_exists("proc_open")) {
 513                 // When was the last time that we called the poller?
 514                 // Less than 5 minutes? Then we quit
 515                 if ((time() - get_config("system", "proc_run_started")) < 300) {
 516                         return;
 517                 }
 518
 519                 // Remove long running and crashed process entries
 520                 poller_kill_stale_workers();
 521
 522                 // Do we have an already running worker? Then we quit here.
 523                 if (poller_active_workers() > 0) {
 524                         return;
 525                 }
 526
 527                 get_app()->proc_run(array('php', 'include/poller.php'));
 528         }
 529
 530         // We cannot execute background processes.
 531         // We now run the processes from the frontend.
 532         // This won't work with long running processes.
 533         poller_run_cron();
 534
 535         clear_worker_processes();
 536
 537         $workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'worker.php'");
 538
 539         if ($workers[0]["processes"] == 0) {
 540                 call_worker();
 541         }
 542 }
 543
 544 /**
 545  * @brief Removes long running worker processes
 546  */
 547 function clear_worker_processes() {
 548         $timeout = Config::get("system", "frontend_worker_timeout", 10);
 549
 550         /// @todo We should clean up the corresponding workerqueue entries as well
 551         q("DELETE FROM `process` WHERE `created` < '%s' AND `command` = 'worker.php'",
 552                 dbesc(datetime_convert('UTC','UTC',"now - ".$timeout." minutes")));
 553 }
 554
 555 /**
 556  * @brief Runs the cron processes
 557  */
 558 function poller_run_cron() {
 559         // Run the cron job that calls all other jobs
 560         proc_run(PRIORITY_MEDIUM, "include/cron.php");
 561
 562         // Run the cronhooks job separately from cron for being able to use a different timing
 563         proc_run(PRIORITY_MEDIUM, "include/cronhooks.php");
 564
 565         // Cleaning dead processes
 566         poller_kill_stale_workers();
 567 }
 568
 569 if (array_search(__file__,get_included_files())===0){
 570         poller_run($_SERVER["argv"],$_SERVER["argc"]);
 571
 572         get_app()->end_process();
 573
 574         killme();
 575 }
 576 ?>