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         $mypid = getmypid();
  39
  40         if ($a->max_processes_reached())
  41                 return;
  42
  43         if (poller_max_connections_reached())
  44                 return;
  45
  46         if (App::maxload_reached())
  47                 return;
  48
  49         // Checking the number of workers
  50         if (poller_too_much_workers()) {
  51                 poller_kill_stale_workers();
  52                 return;
  53         }
  54
  55         if(($argc <= 1) OR ($argv[1] != "no_cron")) {
  56                 // Run the cron job that calls all other jobs
  57                 proc_run(PRIORITY_MEDIUM, "include/cron.php");
  58
  59                 // Run the cronhooks job separately from cron for being able to use a different timing
  60                 proc_run(PRIORITY_MEDIUM, "include/cronhooks.php");
  61
  62                 // Cleaning dead processes
  63                 poller_kill_stale_workers();
  64         } else
  65                 // Sleep four seconds before checking for running processes again to avoid having too many workers
  66                 sleep(4);
  67
  68         // Checking number of workers
  69         if (poller_too_much_workers())
  70                 return;
  71
  72         $cooldown = Config::get("system", "worker_cooldown", 0);
  73
  74         $starttime = time();
  75
  76         while ($r = poller_worker_process()) {
  77
  78                 // Quit when in maintenance
  79                 if (get_config('system', 'maintenance', true))
  80                         return;
  81
  82                 // Constantly check the number of parallel database processes
  83                 if ($a->max_processes_reached())
  84                         return;
  85
  86                 // Constantly check the number of available database connections to let the frontend be accessible at any time
  87                 if (poller_max_connections_reached())
  88                         return;
  89
  90                 // Count active workers and compare them with a maximum value that depends on the load
  91                 if (poller_too_much_workers())
  92                         return;
  93
  94                 q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
  95                         dbesc(datetime_convert()),
  96                         intval($mypid),
  97                         intval($r[0]["id"]));
  98
  99                 // Assure that there are no tasks executed twice
 100                 $id = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 101                 if (!$id) {
 102                         logger("Queue item ".$r[0]["id"]." vanished - skip this execution", LOGGER_DEBUG);
 103                         continue;
 104                 } elseif ((strtotime($id[0]["executed"]) <= 0) OR ($id[0]["pid"] == 0)) {
 105                         logger("Entry for queue item ".$r[0]["id"]." wasn't stored - we better stop here", LOGGER_DEBUG);
 106                         return;
 107                 } elseif ($id[0]["pid"] != $mypid) {
 108                         logger("Queue item ".$r[0]["id"]." is to be executed by process ".$id[0]["pid"]." and not by me (".$mypid.") - skip this execution", LOGGER_DEBUG);
 109                         continue;
 110                 }
 111
 112                 $argv = json_decode($r[0]["parameter"]);
 113
 114                 $argc = count($argv);
 115
 116                 // Check for existance and validity of the include file
 117                 $include = $argv[0];
 118
 119                 if (!validate_include($include)) {
 120                         logger("Include file ".$argv[0]." is not valid!");
 121                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 122                         continue;
 123                 }
 124
 125                 require_once($include);
 126
 127                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 128
 129                 if (function_exists($funcname)) {
 130                         logger("Process ".$mypid." - Prio ".$r[0]["priority"]." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
 131
 132                         // For better logging create a new process id for every worker call
 133                         // But preserve the old one for the worker
 134                         $old_process_id = $a->process_id;
 135                         $a->process_id = uniqid("wrk", true);
 136
 137                         $funcname($argv, $argc);
 138
 139                         $a->process_id = $old_process_id;
 140
 141                         if ($cooldown > 0) {
 142                                 logger("Process ".$mypid." - Prio ".$r[0]["priority"]." - ID ".$r[0]["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 143                                 sleep($cooldown);
 144                         }
 145
 146                         logger("Process ".$mypid." - Prio ".$r[0]["priority"]." - ID ".$r[0]["id"].": ".$funcname." - done");
 147
 148                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 149                 } else
 150                         logger("Function ".$funcname." does not exist");
 151
 152                 // Quit the poller once every hour
 153                 if (time() > ($starttime + 3600))
 154                         return;
 155         }
 156
 157 }
 158
 159 /**
 160  * @brief Checks if the number of database connections has reached a critical limit.
 161  *
 162  * @return bool Are more than 3/4 of the maximum connections used?
 163  */
 164 function poller_max_connections_reached() {
 165
 166         // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 167         $max = get_config("system", "max_connections");
 168
 169         // Fetch the percentage level where the poller will get active
 170         $maxlevel = get_config("system", "max_connections_level");
 171         if ($maxlevel == 0)
 172                 $maxlevel = 75;
 173
 174         if ($max == 0) {
 175                 // the maximum number of possible user connections can be a system variable
 176                 $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 177                 if ($r)
 178                         $max = $r[0]["Value"];
 179
 180                 // Or it can be granted. This overrides the system variable
 181                 $r = q("SHOW GRANTS");
 182                 if ($r)
 183                         foreach ($r AS $grants) {
 184                                 $grant = array_pop($grants);
 185                                 if (stristr($grant, "GRANT USAGE ON"))
 186                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
 187                                                 $max = $match[1];
 188                         }
 189         }
 190
 191         // If $max is set we will use the processlist to determine the current number of connections
 192         // The processlist only shows entries of the current user
 193         if ($max != 0) {
 194                 $r = q("SHOW PROCESSLIST");
 195                 if (!$r)
 196                         return false;
 197
 198                 $used = count($r);
 199
 200                 logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 201
 202                 $level = ($used / $max) * 100;
 203
 204                 if ($level >= $maxlevel) {
 205                         logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 206                         return true;
 207                 }
 208         }
 209
 210         // We will now check for the system values.
 211         // This limit could be reached although the user limits are fine.
 212         $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 213         if (!$r)
 214                 return false;
 215
 216         $max = intval($r[0]["Value"]);
 217         if ($max == 0)
 218                 return false;
 219
 220         $r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 221         if (!$r)
 222                 return false;
 223
 224         $used = intval($r[0]["Value"]);
 225         if ($used == 0)
 226                 return false;
 227
 228         logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 229
 230         $level = $used / $max * 100;
 231
 232         if ($level < $maxlevel)
 233                 return false;
 234
 235         logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 236         return true;
 237 }
 238
 239 /**
 240  * @brief fix the queue entry if the worker process died
 241  *
 242  */
 243 function poller_kill_stale_workers() {
 244         $r = q("SELECT `pid`, `executed`, `priority`, `parameter` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 245
 246         if (!dbm::is_result($r)) {
 247                 // No processing here needed
 248                 return;
 249         }
 250
 251         foreach($r AS $pid)
 252                 if (!posix_kill($pid["pid"], 0))
 253                         q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 254                                 intval($pid["pid"]));
 255                 else {
 256                         // Kill long running processes
 257
 258                         // Check if the priority is in a valid range
 259                         if (!in_array($pid["priority"], array(PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE)))
 260                                 $pid["priority"] = PRIORITY_MEDIUM;
 261
 262                         // Define the maximum durations
 263                         $max_duration_defaults = array(PRIORITY_CRITICAL => 360, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 360);
 264                         $max_duration = $max_duration_defaults[$pid["priority"]];
 265
 266                         $argv = json_decode($pid["parameter"]);
 267                         $argv[0] = basename($argv[0]);
 268
 269                         // How long is the process already running?
 270                         $duration = (time() - strtotime($pid["executed"])) / 60;
 271                         if ($duration > $max_duration) {
 272                                 logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
 273                                 posix_kill($pid["pid"], SIGTERM);
 274
 275                                 // We killed the stale process.
 276                                 // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 277                                 // Additionally we are lowering the priority.
 278                                 q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `created` = '%s',
 279                                                         `priority` = %d, `pid` = 0 WHERE `pid` = %d",
 280                                         dbesc(datetime_convert()),
 281                                         intval(PRIORITY_NEGLIGIBLE),
 282                                         intval($pid["pid"]));
 283                         } else
 284                                 logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
 285                 }
 286 }
 287
 288 function poller_too_much_workers() {
 289
 290
 291         $queues = get_config("system", "worker_queues");
 292
 293         if ($queues == 0)
 294                 $queues = 4;
 295
 296         $maxqueues = $queues;
 297
 298         $active = poller_active_workers();
 299
 300         // Decrease the number of workers at higher load
 301         $load = current_load();
 302         if($load) {
 303                 $maxsysload = intval(get_config('system','maxloadavg'));
 304                 if($maxsysload < 1)
 305                         $maxsysload = 50;
 306
 307                 $maxworkers = $queues;
 308
 309                 // Some magical mathemathics to reduce the workers
 310                 $exponent = 3;
 311                 $slope = $maxworkers / pow($maxsysload, $exponent);
 312                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 313
 314                 $s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00'");
 315                 $entries = $s[0]["total"];
 316
 317                 if (Config::get("system", "worker_fastlane", false) AND ($queues > 0) AND ($entries > 0) AND ($active >= $queues)) {
 318                         $s = q("SELECT `priority` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `priority` LIMIT 1");
 319                         $top_priority = $s[0]["priority"];
 320
 321                         $s = q("SELECT `id` FROM `workerqueue` WHERE `priority` <= %d AND `executed` != '0000-00-00 00:00:00' LIMIT 1",
 322                                 intval($top_priority));
 323                         $high_running = dbm::is_result($s);
 324
 325                         if (!$high_running AND ($top_priority > PRIORITY_UNDEFINED) AND ($top_priority < PRIORITY_NEGLIGIBLE)) {
 326                                 logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
 327                                 $queues = $active + 1;
 328                         }
 329                 }
 330
 331                 logger("Current load: ".$load." - maximum: ".$maxsysload." - current queues: ".$active."/".$entries." - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
 332
 333                 // Are there fewer workers running as possible? Then fork a new one.
 334                 if (!get_config("system", "worker_dont_fork") AND ($queues > ($active + 1)) AND ($entries > 1)) {
 335                         logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
 336                         $args = array("php", "include/poller.php", "no_cron");
 337                         $a = get_app();
 338                         $a->proc_run($args);
 339                 }
 340         }
 341
 342         return($active >= $queues);
 343 }
 344
 345 function poller_active_workers() {
 346         $workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'poller.php'");
 347
 348         return($workers[0]["processes"]);
 349 }
 350
 351 /**
 352  * @brief Check if we should pass some slow processes
 353  *
 354  * When the active processes of the highest priority are using more than 2/3
 355  * of all processes, we let pass slower processes.
 356  *
 357  * @param string $highest_priority Returns the currently highest priority
 358  * @return bool We let pass a slower process than $highest_priority
 359  */
 360 function poller_passing_slow(&$highest_priority) {
 361
 362         $highest_priority = 0;
 363
 364         $r = q("SELECT `priority`
 365                 FROM `process`
 366                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
 367                 WHERE `process`.`command` = 'poller.php'");
 368
 369         // No active processes at all? Fine
 370         if (!dbm::is_result($r))
 371                 return(false);
 372
 373         $priorities = array();
 374         foreach ($r AS $line)
 375                 $priorities[] = $line["priority"];
 376
 377         // Should not happen
 378         if (count($priorities) == 0)
 379                 return(false);
 380
 381         $highest_priority = min($priorities);
 382
 383         // The highest process is already the slowest one?
 384         // Then we quit
 385         if ($highest_priority == PRIORITY_NEGLIGIBLE)
 386                 return(false);
 387
 388         $high = 0;
 389         foreach ($priorities AS $priority)
 390                 if ($priority == $highest_priority)
 391                         ++$high;
 392
 393         logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
 394         $passing_slow = (($high/count($priorities)) > (2/3));
 395
 396         if ($passing_slow)
 397                 logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
 398
 399         return($passing_slow);
 400 }
 401
 402 /**
 403  * @brief Returns the next worker process
 404  *
 405  * @return string SQL statement
 406  */
 407
 408 function poller_worker_process() {
 409
 410         // Check if we should pass some low priority process
 411         $highest_priority = 0;
 412
 413         if (poller_passing_slow($highest_priority)) {
 414                 // Are there waiting processes with a higher priority than the currently highest?
 415                 $r = q("SELECT * FROM `workerqueue`
 416                                 WHERE `executed` = '0000-00-00 00:00:00' AND `priority` < %d
 417                                 ORDER BY `priority`, `created` LIMIT 1", dbesc($highest_priority));
 418                 if (dbm::is_result($r))
 419                         return $r;
 420
 421                 // Give slower processes some processing time
 422                 $r = q("SELECT * FROM `workerqueue`
 423                                 WHERE `executed` = '0000-00-00 00:00:00' AND `priority` > %d
 424                                 ORDER BY `priority`, `created` LIMIT 1", dbesc($highest_priority));
 425         }
 426
 427         // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 428         if (($highest_priority == 0) OR !dbm::is_result($r))
 429                 $r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `priority`, `created` LIMIT 1");
 430
 431         return $r;
 432 }
 433
 434 if (array_search(__file__,get_included_files())===0){
 435         poller_run($_SERVER["argv"],$_SERVER["argc"]);
 436
 437         get_app()->end_process();
 438
 439         killme();
 440 }
 441 ?>