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($directory);
  11 }
  12
  13 require_once("boot.php");
  14
  15 function poller_run(&$argv, &$argc){
  16         global $a, $db;
  17
  18         if(is_null($a)) {
  19                 $a = new App;
  20         }
  21
  22         if(is_null($db)) {
  23                 @include(".htconfig.php");
  24                 require_once("include/dba.php");
  25                 $db = new dba($db_host, $db_user, $db_pass, $db_data);
  26                 unset($db_host, $db_user, $db_pass, $db_data);
  27         };
  28
  29         $load = current_load();
  30         if($load) {
  31                 $maxsysload = intval(get_config('system','maxloadavg'));
  32                 if($maxsysload < 1)
  33                         $maxsysload = 50;
  34
  35                 if(intval($load) > $maxsysload) {
  36                         logger('system: load ' . $load . ' too high. poller deferred to next scheduled run.');
  37                         return;
  38                 }
  39         }
  40
  41         // Checking the number of workers
  42         if (poller_too_much_workers(1)) {
  43                 poller_kill_stale_workers();
  44                 return;
  45         }
  46
  47         if(($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(2))
  62                 return;
  63
  64         $starttime = time();
  65
  66         while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
  67
  68                 // Count active workers and compare them with a maximum value that depends on the load
  69                 if (poller_too_much_workers(3))
  70                         return;
  71
  72                 q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
  73                         dbesc(datetime_convert()),
  74                         intval(getmypid()),
  75                         intval($r[0]["id"]));
  76
  77                 // Assure that there are no tasks executed twice
  78                 $id = q("SELECT `id` FROM `workerqueue` WHERE `id` = %d AND `pid` = %d",
  79                         intval($r[0]["id"]),
  80                         intval(getmypid()));
  81                 if (!$id) {
  82                         logger("Queue item ".$r[0]["id"]." was executed multiple times - skip this execution", LOGGER_DEBUG);
  83                         continue;
  84                 }
  85
  86                 $argv = json_decode($r[0]["parameter"]);
  87
  88                 $argc = count($argv);
  89
  90                 // Check for existance and validity of the include file
  91                 $include = $argv[0];
  92
  93                 if (!validate_include($include)) {
  94                         logger("Include file ".$argv[0]." is not valid!");
  95                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
  96                         continue;
  97                 }
  98
  99                 require_once($include);
 100
 101                 $funcname=str_replace(".php", "", basename($argv[0]))."_run";
 102
 103                 if (function_exists($funcname)) {
 104                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
 105                         $funcname($argv, $argc);
 106
 107                         logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - done");
 108
 109                         q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
 110                 } else
 111                         logger("Function ".$funcname." does not exist");
 112
 113                 // Quit the poller once every hour
 114                 if (time() > ($starttime + 3600))
 115                         return;
 116         }
 117
 118 }
 119
 120 /**
 121  * @brief fix the queue entry if the worker process died
 122  *
 123  */
 124 function poller_kill_stale_workers() {
 125         $r = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 126         foreach($r AS $pid)
 127                 if (!posix_kill($pid["pid"], 0))
 128                         q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 129                                 intval($pid["pid"]));
 130                 else {
 131                         // Kill long running processes
 132                         $duration = (time() - strtotime($pid["executed"])) / 60;
 133                         if ($duration > 180) {
 134                                 logger("Worker process ".$pid["pid"]." took more than 3 hours. It will be killed now.");
 135                                 posix_kill($pid["pid"], SIGTERM);
 136
 137                                 // Question: If a process is stale: Should we remove it or should we reschedule it?
 138                                 // By now we rescheduling it. It's maybe not the wisest decision?
 139                                 q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
 140                                         intval($pid["pid"]));
 141                         } else
 142                                 logger("Worker process ".$pid["pid"]." now runs for ".round($duration)." minutes. That's okay.", LOGGER_DEBUG);
 143                 }
 144 }
 145
 146 function poller_too_much_workers($stage) {
 147
 148         $queues = get_config("system", "worker_queues");
 149
 150         if ($queues == 0)
 151                 $queues = 4;
 152
 153         $active = poller_active_workers();
 154
 155         // Decrease the number of workers at higher load
 156         $load = current_load();
 157         if($load) {
 158                 $maxsysload = intval(get_config('system','maxloadavg'));
 159                 if($maxsysload < 1)
 160                         $maxsysload = 50;
 161
 162                 $maxworkers = $queues;
 163
 164                 // Some magical mathemathics to reduce the workers
 165                 $exponent = 3;
 166                 $slope = $maxworkers / pow($maxsysload, $exponent);
 167                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 168
 169                 logger("Current load stage ".$stage.": ".$load." - maximum: ".$maxsysload." - current queues: ".$active." - maximum: ".$queues, LOGGER_DEBUG);
 170
 171         }
 172
 173         return($active >= $queues);
 174 }
 175
 176 function poller_active_workers() {
 177         $workers = q("SELECT COUNT(*) AS `workers` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
 178
 179         return($workers[0]["workers"]);
 180 }
 181
 182 if (array_search(__file__,get_included_files())===0){
 183   poller_run($_SERVER["argv"],$_SERVER["argc"]);
 184   killme();
 185 }
 186 ?>