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