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("Processcheck: Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
  33
  34                 $max_processes = get_config('system', 'max_processes_backend');
  35                 if (intval($max_processes) == 0)
  36                         $max_processes = 5;
  37
  38                 if ($processlist["amount"] > $max_processes) {
  39                         logger("Processcheck: Maximum number of processes for backend tasks (".$max_processes.") reached.", LOGGER_DEBUG);
  40                         return;
  41                 }
  42         }
  43
  44         if (poller_max_connections_reached())
  45                 return;
  46
  47         if (App::maxload_reached())
  48                 return;
  49
  50         // Checking the number of workers
  51         if (poller_too_much_workers(1)) {
  52                 poller_kill_stale_workers();
  53                 return;
  54         }
  55
  56         if(($argc <= 1) OR ($argv[1] != "no_cron")) {
  57                 // Run the cron job that calls all other jobs
  58                 proc_run("php","include/cron.php");
  59
  60                 // Run the cronhooks job separately from cron for being able to use a different timing
  61                 proc_run("php","include/cronhooks.php");
  62
  63                 // Cleaning dead processes
  64                 poller_kill_stale_workers();
  65         } else
  66                 // Sleep four seconds before checking for running processes again to avoid having too many workers
  67                 sleep(4);
  68
  69         // Checking number of workers
  70         if (poller_too_much_workers(2))
  71                 return;
  72
  73         $starttime = time();
  74
  75         while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
  76
  77                 // Log the type of database processes
  78                 $processlist = dbm::processlist();
  79                 if ($processlist["amount"] != "") {
  80                         logger("Processcheck: Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
  81
  82                         $max_processes = get_config('system', 'max_processes_backend');
  83                         if (intval($max_processes) == 0)
  84                                 $max_processes = 5;
  85
  86                         if ($processlist["amount"] > $max_processes) {
  87                                 logger("Processcheck: Maximum number of processes for backend tasks (".$max_processes.") reached.", LOGGER_DEBUG);
  88                                 return;
  89                         }
  90                 }
  91
  92                 // Constantly check the number of available database connections to let the frontend be accessible at any time
  93                 if (poller_max_connections_reached())
  94                         return;
  95
  96                 // Count active workers and compare them with a maximum value that depends on the load
  97                 if (poller_too_much_workers(3))
  98                         return;
  99
 100                 q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
 101                         dbesc(datetime_convert()),
 102                         intval(getmypid()),
 103                         intval($r[0]["id"]));
 104
 105                 // Assure that there are no tasks executed twice
 106                 $id = q("SELECT `id` FROM `workerqueue` WHERE `id` = %d AND `pid` = %d",
 107                         intval($r[0]["id"]),
 108                         intval(getmypid()));
 109                 if (!$id) {
 110                         logger("Queue item ".$r[0]["id"]." was executed multiple times - skip this execution", LOGGER_DEBUG);
 111                         continue;
 112                 }
 113
 114                 $argv = json_decode($r[0]["parameter"]);
 115
 116                 $argc = count($argv);
 117
 118                 // Check for existance and validity of the include file
 119                 $include = $argv[0];
 120
 121                 if (!validate_include($include)) {
 122                         logger("Include file ".$argv[0]." is not valid!");
 123                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 124                         continue;
 125                 }
 126
 127                 require_once($include);
 128
 129                 $funcname=str_replace(".php", "", basename($argv[0]))."_run";
 130
 131                 if (function_exists($funcname)) {
 132                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
 133                         $funcname($argv, $argc);
 134
 135                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - done");
 136
 137                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 138                 } else
 139                         logger("Function ".$funcname." does not exist");
 140
 141                 // Quit the poller once every hour
 142                 if (time() > ($starttime + 3600))
 143                         return;
 144         }
 145
 146 }
 147
 148 /**
 149  * @brief Checks if the number of database connections has reached a critical limit.
 150  *
 151  * @return bool Are more than 3/4 of the maximum connections used?
 152  */
 153 function poller_max_connections_reached() {
 154
 155         // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 156         $max = get_config("system", "max_connections");
 157
 158         // Fetch the percentage level where the poller will get active
 159         $maxlevel = get_config("system", "max_connections_level");
 160         if ($maxlevel == 0)
 161                 $maxlevel = 75;
 162
 163         if ($max == 0) {
 164                 // the maximum number of possible user connections can be a system variable
 165                 $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 166                 if ($r)
 167                         $max = $r[0]["Value"];
 168
 169                 // Or it can be granted. This overrides the system variable
 170                 $r = q("SHOW GRANTS");
 171                 if ($r)
 172                         foreach ($r AS $grants) {
 173                                 $grant = array_pop($grants);
 174                                 if (stristr($grant, "GRANT USAGE ON"))
 175                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
 176                                                 $max = $match[1];
 177                         }
 178         }
 179
 180         // If $max is set we will use the processlist to determine the current number of connections
 181         // The processlist only shows entries of the current user
 182         if ($max != 0) {
 183                 $r = q("SHOW PROCESSLIST");
 184                 if (!$r)
 185                         return false;
 186
 187                 $used = count($r);
 188
 189                 logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 190
 191                 $level = ($used / $max) * 100;
 192
 193                 if ($level >= $maxlevel) {
 194                         logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 195                         return true;
 196                 }
 197         }
 198
 199         // We will now check for the system values.
 200         // This limit could be reached although the user limits are fine.
 201         $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 202         if (!$r)
 203                 return false;
 204
 205         $max = intval($r[0]["Value"]);
 206         if ($max == 0)
 207                 return false;
 208
 209         $r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 210         if (!$r)
 211                 return false;
 212
 213         $used = intval($r[0]["Value"]);
 214         if ($used == 0)
 215                 return false;
 216
 217         logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 218
 219         $level = $used / $max * 100;
 220
 221         if ($level < $maxlevel)
 222                 return false;
 223
 224         logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 225         return true;
 226 }
 227
 228 /**
 229  * @brief fix the queue entry if the worker process died
 230  *
 231  */
 232 function poller_kill_stale_workers() {
 233         $r = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 234
 235         if (!is_array($r) || count($r) == 0) {
 236                 // No processing here needed
 237                 return;
 238         }
 239
 240         foreach($r AS $pid)
 241                 if (!posix_kill($pid["pid"], 0))
 242                         q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 243                                 intval($pid["pid"]));
 244                 else {
 245                         // Kill long running processes
 246                         $duration = (time() - strtotime($pid["executed"])) / 60;
 247                         if ($duration > 180) {
 248                                 logger("Worker process ".$pid["pid"]." took more than 3 hours. It will be killed now.");
 249                                 posix_kill($pid["pid"], SIGTERM);
 250
 251                                 // Question: If a process is stale: Should we remove it or should we reschedule it?
 252                                 // By now we rescheduling it. It's maybe not the wisest decision?
 253                                 q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 254                                         intval($pid["pid"]));
 255                         } else
 256                                 logger("Worker process ".$pid["pid"]." now runs for ".round($duration)." minutes. That's okay.", LOGGER_DEBUG);
 257                 }
 258 }
 259
 260 function poller_too_much_workers($stage) {
 261
 262         $queues = get_config("system", "worker_queues");
 263
 264         if ($queues == 0)
 265                 $queues = 4;
 266
 267         $active = poller_active_workers();
 268
 269         // Decrease the number of workers at higher load
 270         $load = current_load();
 271         if($load) {
 272                 $maxsysload = intval(get_config('system','maxloadavg'));
 273                 if($maxsysload < 1)
 274                         $maxsysload = 50;
 275
 276                 $maxworkers = $queues;
 277
 278                 // Some magical mathemathics to reduce the workers
 279                 $exponent = 3;
 280                 $slope = $maxworkers / pow($maxsysload, $exponent);
 281                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 282
 283                 logger("Current load stage ".$stage.": ".$load." - maximum: ".$maxsysload." - current queues: ".$active." - maximum: ".$queues, LOGGER_DEBUG);
 284
 285         }
 286
 287         return($active >= $queues);
 288 }
 289
 290 function poller_active_workers() {
 291         $workers = q("SELECT COUNT(*) AS `workers` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 292
 293         return($workers[0]["workers"]);
 294 }
 295
 296 if (array_search(__file__,get_included_files())===0){
 297   poller_run($_SERVER["argv"],$_SERVER["argc"]);
 298   killme();
 299 }
 300 ?>