friendica/include/poller.php

266 lines
7.2 KiB
PHP

<?php
if (!file_exists("boot.php") AND (sizeof($_SERVER["argv"]) != 0)) {
$directory = dirname($_SERVER["argv"][0]);
if (substr($directory, 0, 1) != "/")
$directory = $_SERVER["PWD"]."/".$directory;
$directory = realpath($directory."/..");
chdir($directory);
}
require_once("boot.php");
function poller_run(&$argv, &$argc){
global $a, $db;
if(is_null($a)) {
$a = new App;
}
if(is_null($db)) {
@include(".htconfig.php");
require_once("include/dba.php");
$db = new dba($db_host, $db_user, $db_pass, $db_data);
unset($db_host, $db_user, $db_pass, $db_data);
};
if (poller_max_connections_reached())
return;
if (App::maxload_reached())
return;
// Checking the number of workers
if (poller_too_much_workers(1)) {
poller_kill_stale_workers();
return;
}
if(($argc <= 1) OR ($argv[1] != "no_cron")) {
// Run the cron job that calls all other jobs
proc_run("php","include/cron.php");
// Run the cronhooks job separately from cron for being able to use a different timing
proc_run("php","include/cronhooks.php");
// Cleaning dead processes
poller_kill_stale_workers();
} else
// Sleep four seconds before checking for running processes again to avoid having too many workers
sleep(4);
// Checking number of workers
if (poller_too_much_workers(2))
return;
$starttime = time();
while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
// Constantly check the number of available database connections to let the frontend be accessible at any time
if (poller_max_connections_reached())
return;
// Count active workers and compare them with a maximum value that depends on the load
if (poller_too_much_workers(3))
return;
q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
dbesc(datetime_convert()),
intval(getmypid()),
intval($r[0]["id"]));
// Assure that there are no tasks executed twice
$id = q("SELECT `id` FROM `workerqueue` WHERE `id` = %d AND `pid` = %d",
intval($r[0]["id"]),
intval(getmypid()));
if (!$id) {
logger("Queue item ".$r[0]["id"]." was executed multiple times - skip this execution", LOGGER_DEBUG);
continue;
}
$argv = json_decode($r[0]["parameter"]);
$argc = count($argv);
// Check for existance and validity of the include file
$include = $argv[0];
if (!validate_include($include)) {
logger("Include file ".$argv[0]." is not valid!");
q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
continue;
}
require_once($include);
$funcname=str_replace(".php", "", basename($argv[0]))."_run";
if (function_exists($funcname)) {
logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
$funcname($argv, $argc);
logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - done");
q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
} else
logger("Function ".$funcname." does not exist");
// Quit the poller once every hour
if (time() > ($starttime + 3600))
return;
}
}
/**
* @brief Checks if the number of database connections has reached a critical limit.
*
* @return bool Are more than 3/4 of the maximum connections used?
*/
function poller_max_connections_reached() {
// Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
$max = get_config("system", "max_connections");
if ($max == 0) {
// the maximum number of possible user connections can be a system variable
$r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
if ($r)
$max = $r[0]["Value"];
// Or it can be granted. This overrides the system variable
$r = q("SHOW GRANTS");
if ($r)
foreach ($r AS $grants) {
$grant = array_pop($grants);
if (stristr($grant, "GRANT USAGE ON"))
if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
$max = $match[1];
}
}
// If $max is set we will use the processlist to determine the current number of connections
// The processlist only shows entries of the current user
if ($max != 0) {
$r = q("SHOW PROCESSLIST");
if (!$r)
return false;
$used = count($r);
logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
$level = $used / $max;
if ($level >= (3/4)) {
logger("Maximum level (3/4) of user connections reached: ".$used."/".$max);
return true;
}
}
// We will now check for the system values.
// This limit could be reached although the user limits are fine.
$r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
if (!$r)
return false;
$max = intval($r[0]["Value"]);
if ($max == 0)
return false;
$r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
if (!$r)
return false;
$used = intval($r[0]["Value"]);
if ($used == 0)
return false;
logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
$level = $used / $max;
if ($level < (3/4))
return false;
logger("Maximum level (3/4) of system connections reached: ".$used."/".$max);
return true;
}
/**
* @brief fix the queue entry if the worker process died
*
*/
function poller_kill_stale_workers() {
$r = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
if (!is_array($r) || count($r) == 0) {
// No processing here needed
return;
}
foreach($r AS $pid)
if (!posix_kill($pid["pid"], 0))
q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
intval($pid["pid"]));
else {
// Kill long running processes
$duration = (time() - strtotime($pid["executed"])) / 60;
if ($duration > 180) {
logger("Worker process ".$pid["pid"]." took more than 3 hours. It will be killed now.");
posix_kill($pid["pid"], SIGTERM);
// Question: If a process is stale: Should we remove it or should we reschedule it?
// By now we rescheduling it. It's maybe not the wisest decision?
q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
intval($pid["pid"]));
} else
logger("Worker process ".$pid["pid"]." now runs for ".round($duration)." minutes. That's okay.", LOGGER_DEBUG);
}
}
function poller_too_much_workers($stage) {
$queues = get_config("system", "worker_queues");
if ($queues == 0)
$queues = 4;
$active = poller_active_workers();
// Decrease the number of workers at higher load
$load = current_load();
if($load) {
$maxsysload = intval(get_config('system','maxloadavg'));
if($maxsysload < 1)
$maxsysload = 50;
$maxworkers = $queues;
// Some magical mathemathics to reduce the workers
$exponent = 3;
$slope = $maxworkers / pow($maxsysload, $exponent);
$queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
logger("Current load stage ".$stage.": ".$load." - maximum: ".$maxsysload." - current queues: ".$active." - maximum: ".$queues, LOGGER_DEBUG);
}
return($active >= $queues);
}
function poller_active_workers() {
$workers = q("SELECT COUNT(*) AS `workers` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
return($workers[0]["workers"]);
}
if (array_search(__file__,get_included_files())===0){
poller_run($_SERVER["argv"],$_SERVER["argc"]);
killme();
}
?>