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, $db_data);
  30         };
  31
  32         if ($a->max_processes_reached())
  33                 return;
  34
  35         if (poller_max_connections_reached())
  36                 return;
  37
  38         if (App::maxload_reached())
  39                 return;
  40
  41         // Checking the number of workers
  42         if (poller_too_much_workers($entries, $queues, $maxqueues, $active)) {
  43                 poller_kill_stale_workers();
  44                 return;
  45         }
  46
  47         if(($argc <= 1) OR ($argv[1] != "no_cron")) {
  48                 // Run the cron job that calls all other jobs
  49                 proc_run("php","include/cron.php");
  50
  51                 // Run the cronhooks job separately from cron for being able to use a different timing
  52                 proc_run("php","include/cronhooks.php");
  53
  54                 // Cleaning dead processes
  55                 poller_kill_stale_workers();
  56         } else
  57                 // Sleep four seconds before checking for running processes again to avoid having too many workers
  58                 sleep(4);
  59
  60         // Checking number of workers
  61         if (poller_too_much_workers($entries, $queues, $maxqueues, $active))
  62                 return;
  63
  64         $cooldown = Config::get("system", "worker_cooldown", 0);
  65
  66         $starttime = time();
  67
  68         $delayed = 0;
  69
  70         while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
  71
  72                 // Constantly check the number of parallel database processes
  73                 if ($a->max_processes_reached())
  74                         return;
  75
  76                 // Constantly check the number of available database connections to let the frontend be accessible at any time
  77                 if (poller_max_connections_reached())
  78                         return;
  79
  80                 // Count active workers and compare them with a maximum value that depends on the load
  81                 if (poller_too_much_workers($entries, $queues, $maxqueues, $active))
  82                         return;
  83
  84                 $argv = json_decode($r[0]["parameter"]);
  85
  86                 $argc = count($argv);
  87
  88                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
  89
  90                 // Define the processes that have priority over any other process
  91                 /// @todo Better check for priority processes
  92                 $priority = array("delivery_run", "notifier_run", "pubsubpublish_run");
  93
  94                 // Reserve a speed lane
  95                 if (($active == ($queues - 1)) AND ($maxqueues >= 2) AND !in_array($funcname, $priority)) {
  96                         logger("Delay call to '".$funcname."' to reserve a speed lane for high priority processes", LOGGER_DEBUG);
  97                         $delay = true;
  98                 }
  99
 100                 // Delay other processes if the system has a high load and there are many pending processes.
 101                 // The "delayed" value is a safety mechanism for the case when there are no high priority processes in the queue.
 102                 if (!$delay AND (($queues / $maxqueues) <= 0.5) AND (($entries > 100) AND ($delayed < 100)) AND !in_array($funcname, $priority)) {
 103                         // Count the number of delayed processes
 104                         ++$delayed;
 105                         logger("Delay call to '".$funcname."' for performance reasons (Delay ".$delayed.")", LOGGER_DEBUG);
 106                         $delay = true;
 107                 }
 108
 109                 if ($delay) {
 110                         q("UPDATE `workerqueue` SET `created` = '%s' WHERE `id` = %d",
 111                                 dbesc(datetime_convert()),
 112                                 intval($r[0]["id"]));
 113                         continue;
 114                 }
 115
 116                 // If we delivered a process that has high priority we reset the delayed counter.
 117                 // When we reached the limit we will process any entry until we reach a high priority process.
 118                 if (in_array($funcname, $priority))
 119                         $delayed = 0;
 120
 121                 q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
 122                         dbesc(datetime_convert()),
 123                         intval(getmypid()),
 124                         intval($r[0]["id"]));
 125
 126                 // Assure that there are no tasks executed twice
 127                 $id = q("SELECT `id` FROM `workerqueue` WHERE `id` = %d AND `pid` = %d",
 128                         intval($r[0]["id"]),
 129                         intval(getmypid()));
 130                 if (!$id) {
 131                         logger("Queue item ".$r[0]["id"]." was executed multiple times - skip this execution", LOGGER_DEBUG);
 132                         continue;
 133                 }
 134
 135                 // Check for existance and validity of the include file
 136                 $include = $argv[0];
 137
 138                 if (!validate_include($include)) {
 139                         logger("Include file ".$argv[0]." is not valid!");
 140                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 141                         continue;
 142                 }
 143
 144                 require_once($include);
 145
 146                 if (function_exists($funcname)) {
 147                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
 148                         $funcname($argv, $argc);
 149
 150                         if ($cooldown > 0) {
 151                                 logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 152                                 sleep($cooldown);
 153                         }
 154
 155                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - done");
 156
 157                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 158                 } else
 159                         logger("Function ".$funcname." does not exist");
 160
 161                 // Quit the poller once every hour
 162                 if (time() > ($starttime + 3600))
 163                         return;
 164         }
 165
 166 }
 167
 168 /**
 169  * @brief Checks if the number of database connections has reached a critical limit.
 170  *
 171  * @return bool Are more than 3/4 of the maximum connections used?
 172  */
 173 function poller_max_connections_reached() {
 174
 175         // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 176         $max = get_config("system", "max_connections");
 177
 178         // Fetch the percentage level where the poller will get active
 179         $maxlevel = get_config("system", "max_connections_level");
 180         if ($maxlevel == 0)
 181                 $maxlevel = 75;
 182
 183         if ($max == 0) {
 184                 // the maximum number of possible user connections can be a system variable
 185                 $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 186                 if ($r)
 187                         $max = $r[0]["Value"];
 188
 189                 // Or it can be granted. This overrides the system variable
 190                 $r = q("SHOW GRANTS");
 191                 if ($r)
 192                         foreach ($r AS $grants) {
 193                                 $grant = array_pop($grants);
 194                                 if (stristr($grant, "GRANT USAGE ON"))
 195                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
 196                                                 $max = $match[1];
 197                         }
 198         }
 199
 200         // If $max is set we will use the processlist to determine the current number of connections
 201         // The processlist only shows entries of the current user
 202         if ($max != 0) {
 203                 $r = q("SHOW PROCESSLIST");
 204                 if (!$r)
 205                         return false;
 206
 207                 $used = count($r);
 208
 209                 logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 210
 211                 $level = ($used / $max) * 100;
 212
 213                 if ($level >= $maxlevel) {
 214                         logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 215                         return true;
 216                 }
 217         }
 218
 219         // We will now check for the system values.
 220         // This limit could be reached although the user limits are fine.
 221         $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 222         if (!$r)
 223                 return false;
 224
 225         $max = intval($r[0]["Value"]);
 226         if ($max == 0)
 227                 return false;
 228
 229         $r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 230         if (!$r)
 231                 return false;
 232
 233         $used = intval($r[0]["Value"]);
 234         if ($used == 0)
 235                 return false;
 236
 237         logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 238
 239         $level = $used / $max * 100;
 240
 241         if ($level < $maxlevel)
 242                 return false;
 243
 244         logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 245         return true;
 246 }
 247
 248 /**
 249  * @brief fix the queue entry if the worker process died
 250  *
 251  */
 252 function poller_kill_stale_workers() {
 253         $r = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 254
 255         if (!dbm::is_result($r)) {
 256                 // No processing here needed
 257                 return;
 258         }
 259
 260         foreach($r AS $pid)
 261                 if (!posix_kill($pid["pid"], 0))
 262                         q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 263                                 intval($pid["pid"]));
 264                 else {
 265                         // Kill long running processes
 266                         $duration = (time() - strtotime($pid["executed"])) / 60;
 267                         if ($duration > 180) {
 268                                 logger("Worker process ".$pid["pid"]." took more than 3 hours. It will be killed now.");
 269                                 posix_kill($pid["pid"], SIGTERM);
 270
 271                                 // Question: If a process is stale: Should we remove it or should we reschedule it?
 272                                 // By now we rescheduling it. It's maybe not the wisest decision?
 273                                 q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 274                                         intval($pid["pid"]));
 275                         } else
 276                                 logger("Worker process ".$pid["pid"]." now runs for ".round($duration)." minutes. That's okay.", LOGGER_DEBUG);
 277                 }
 278 }
 279
 280 function poller_too_much_workers(&$entries, &$queues, &$maxqueues, &$active) {
 281
 282         $entries = 0;
 283
 284         $queues = get_config("system", "worker_queues");
 285
 286         if ($queues == 0)
 287                 $queues = 4;
 288
 289         $maxqueues = $queues;
 290
 291         $active = poller_active_workers();
 292
 293         // Decrease the number of workers at higher load
 294         $load = current_load();
 295         if($load) {
 296                 $maxsysload = intval(get_config('system','maxloadavg'));
 297                 if($maxsysload < 1)
 298                         $maxsysload = 50;
 299
 300                 $maxworkers = $queues;
 301
 302                 // Some magical mathemathics to reduce the workers
 303                 $exponent = 3;
 304                 $slope = $maxworkers / pow($maxsysload, $exponent);
 305                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 306
 307                 $s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00'");
 308                 $entries = $s[0]["total"];
 309
 310                 logger("Current load: ".$load." - maximum: ".$maxsysload." - current queues: ".$active."/".$entries." - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
 311
 312         }
 313
 314         return($active >= $queues);
 315 }
 316
 317 function poller_active_workers() {
 318         $workers = q("SELECT COUNT(*) AS `workers` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 319
 320         return($workers[0]["workers"]);
 321 }
 322
 323 if (array_search(__file__,get_included_files())===0){
 324   poller_run($_SERVER["argv"],$_SERVER["argc"]);
 325   killme();
 326 }
 327 ?>