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($directory);
  11 }
  12
  13 require_once("boot.php");
  14 require_once("dbm.php");
  15
  16 function poller_run(&$argv, &$argc){
  17         global $a, $db;
  18
  19         if(is_null($a)) {
  20                 $a = new App;
  21         }
  22
  23         if(is_null($db)) {
  24                 @include(".htconfig.php");
  25                 require_once("include/dba.php");
  26                 $db = new dba($db_host, $db_user, $db_pass, $db_data);
  27                 unset($db_host, $db_user, $db_pass, $db_data);
  28         };
  29
  30         $processlist = dbm::processlist();
  31         if ($processlist["list"] != "") {
  32                 logger("Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
  33                 if ($processlist["amount"] > 5)
  34                         return;
  35         }
  36
  37         if (poller_max_connections_reached())
  38                 return;
  39
  40         if (App::maxload_reached())
  41                 return;
  42
  43         // Checking the number of workers
  44         if (poller_too_much_workers(1)) {
  45                 poller_kill_stale_workers();
  46                 return;
  47         }
  48
  49         if(($argc <= 1) OR ($argv[1] != "no_cron")) {
  50                 // Run the cron job that calls all other jobs
  51                 proc_run("php","include/cron.php");
  52
  53                 // Run the cronhooks job separately from cron for being able to use a different timing
  54                 proc_run("php","include/cronhooks.php");
  55
  56                 // Cleaning dead processes
  57                 poller_kill_stale_workers();
  58         } else
  59                 // Sleep four seconds before checking for running processes again to avoid having too many workers
  60                 sleep(4);
  61
  62         // Checking number of workers
  63         if (poller_too_much_workers(2))
  64                 return;
  65
  66         $starttime = time();
  67
  68         while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
  69
  70                 // Log the type of database processes
  71                 $processlist = dbm::processlist();
  72                 if ($processlist["amount"] != "") {
  73                         logger("Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
  74                         if ($processlist["amount"] > 5)
  75                                 return;
  76                 }
  77
  78                 // Constantly check the number of available database connections to let the frontend be accessible at any time
  79                 if (poller_max_connections_reached())
  80                         return;
  81
  82                 // Count active workers and compare them with a maximum value that depends on the load
  83                 if (poller_too_much_workers(3))
  84                         return;
  85
  86                 q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
  87                         dbesc(datetime_convert()),
  88                         intval(getmypid()),
  89                         intval($r[0]["id"]));
  90
  91                 // Assure that there are no tasks executed twice
  92                 $id = q("SELECT `id` FROM `workerqueue` WHERE `id` = %d AND `pid` = %d",
  93                         intval($r[0]["id"]),
  94                         intval(getmypid()));
  95                 if (!$id) {
  96                         logger("Queue item ".$r[0]["id"]." was executed multiple times - skip this execution", LOGGER_DEBUG);
  97                         continue;
  98                 }
  99
 100                 $argv = json_decode($r[0]["parameter"]);
 101
 102                 $argc = count($argv);
 103
 104                 // Check for existance and validity of the include file
 105                 $include = $argv[0];
 106
 107                 if (!validate_include($include)) {
 108                         logger("Include file ".$argv[0]." is not valid!");
 109                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 110                         continue;
 111                 }
 112
 113                 require_once($include);
 114
 115                 $funcname=str_replace(".php", "", basename($argv[0]))."_run";
 116
 117                 if (function_exists($funcname)) {
 118                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
 119                         $funcname($argv, $argc);
 120
 121                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - done");
 122
 123                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 124                 } else
 125                         logger("Function ".$funcname." does not exist");
 126
 127                 // Quit the poller once every hour
 128                 if (time() > ($starttime + 3600))
 129                         return;
 130         }
 131
 132 }
 133
 134 /**
 135  * @brief Checks if the number of database connections has reached a critical limit.
 136  *
 137  * @return bool Are more than 3/4 of the maximum connections used?
 138  */
 139 function poller_max_connections_reached() {
 140
 141         // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 142         $max = get_config("system", "max_connections");
 143
 144         // Fetch the percentage level where the poller will get active
 145         $maxlevel = get_config("system", "max_connections_level");
 146         if ($maxlevel == 0)
 147                 $maxlevel = 75;
 148
 149         if ($max == 0) {
 150                 // the maximum number of possible user connections can be a system variable
 151                 $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 152                 if ($r)
 153                         $max = $r[0]["Value"];
 154
 155                 // Or it can be granted. This overrides the system variable
 156                 $r = q("SHOW GRANTS");
 157                 if ($r)
 158                         foreach ($r AS $grants) {
 159                                 $grant = array_pop($grants);
 160                                 if (stristr($grant, "GRANT USAGE ON"))
 161                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
 162                                                 $max = $match[1];
 163                         }
 164         }
 165
 166         // If $max is set we will use the processlist to determine the current number of connections
 167         // The processlist only shows entries of the current user
 168         if ($max != 0) {
 169                 $r = q("SHOW PROCESSLIST");
 170                 if (!$r)
 171                         return false;
 172
 173                 $used = count($r);
 174
 175                 logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 176
 177                 $level = ($used / $max) * 100;
 178
 179                 if ($level >= $maxlevel) {
 180                         logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 181                         return true;
 182                 }
 183         }
 184
 185         // We will now check for the system values.
 186         // This limit could be reached although the user limits are fine.
 187         $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 188         if (!$r)
 189                 return false;
 190
 191         $max = intval($r[0]["Value"]);
 192         if ($max == 0)
 193                 return false;
 194
 195         $r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 196         if (!$r)
 197                 return false;
 198
 199         $used = intval($r[0]["Value"]);
 200         if ($used == 0)
 201                 return false;
 202
 203         logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 204
 205         $level = $used / $max * 100;
 206
 207         if ($level < $maxlevel)
 208                 return false;
 209
 210         logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 211         return true;
 212 }
 213
 214 /**
 215  * @brief fix the queue entry if the worker process died
 216  *
 217  */
 218 function poller_kill_stale_workers() {
 219         $r = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 220
 221         if (!is_array($r) || count($r) == 0) {
 222                 // No processing here needed
 223                 return;
 224         }
 225
 226         foreach($r AS $pid)
 227                 if (!posix_kill($pid["pid"], 0))
 228                         q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 229                                 intval($pid["pid"]));
 230                 else {
 231                         // Kill long running processes
 232                         $duration = (time() - strtotime($pid["executed"])) / 60;
 233                         if ($duration > 180) {
 234                                 logger("Worker process ".$pid["pid"]." took more than 3 hours. It will be killed now.");
 235                                 posix_kill($pid["pid"], SIGTERM);
 236
 237                                 // Question: If a process is stale: Should we remove it or should we reschedule it?
 238                                 // By now we rescheduling it. It's maybe not the wisest decision?
 239                                 q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 240                                         intval($pid["pid"]));
 241                         } else
 242                                 logger("Worker process ".$pid["pid"]." now runs for ".round($duration)." minutes. That's okay.", LOGGER_DEBUG);
 243                 }
 244 }
 245
 246 function poller_too_much_workers($stage) {
 247
 248         $queues = get_config("system", "worker_queues");
 249
 250         if ($queues == 0)
 251                 $queues = 4;
 252
 253         $active = poller_active_workers();
 254
 255         // Decrease the number of workers at higher load
 256         $load = current_load();
 257         if($load) {
 258                 $maxsysload = intval(get_config('system','maxloadavg'));
 259                 if($maxsysload < 1)
 260                         $maxsysload = 50;
 261
 262                 $maxworkers = $queues;
 263
 264                 // Some magical mathemathics to reduce the workers
 265                 $exponent = 3;
 266                 $slope = $maxworkers / pow($maxsysload, $exponent);
 267                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 268
 269                 logger("Current load stage ".$stage.": ".$load." - maximum: ".$maxsysload." - current queues: ".$active." - maximum: ".$queues, LOGGER_DEBUG);
 270
 271         }
 272
 273         return($active >= $queues);
 274 }
 275
 276 function poller_active_workers() {
 277         $workers = q("SELECT COUNT(*) AS `workers` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 278
 279         return($workers[0]["workers"]);
 280 }
 281
 282 if (array_search(__file__,get_included_files())===0){
 283   poller_run($_SERVER["argv"],$_SERVER["argc"]);
 284   killme();
 285 }
 286 ?>