friendica_2021-01/include/poller.php
2016-10-11 06:30:53 +00:00

462 lines
14 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($directory);
}
use \Friendica\Core\Config;
use \Friendica\Core\PConfig;
require_once("boot.php");
function poller_run(&$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);
};
// Quit when in maintenance
if (get_config('system', 'maintenance', true))
return;
$a->start_process();
$mypid = getmypid();
if ($a->max_processes_reached())
return;
if (poller_max_connections_reached())
return;
if (App::maxload_reached())
return;
// Checking the number of workers
if (poller_too_much_workers()) {
poller_kill_stale_workers();
return;
}
if(($argc <= 1) OR ($argv[1] != "no_cron")) {
// Run the cron job that calls all other jobs
proc_run(PRIORITY_MEDIUM, "include/cron.php");
// Run the cronhooks job separately from cron for being able to use a different timing
proc_run(PRIORITY_MEDIUM, "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())
return;
$cooldown = Config::get("system", "worker_cooldown", 0);
$starttime = time();
while ($r = poller_worker_process()) {
// Quit when in maintenance
if (get_config('system', 'maintenance', true))
return;
// Constantly check the number of parallel database processes
if ($a->max_processes_reached())
return;
// Constantly check the number of available database connections to let the frontend be accessible at any time
if (poller_max_connections_reached())
return;
// Count active workers and compare them with a maximum value that depends on the load
if (poller_too_much_workers())
return;
q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
dbesc(datetime_convert()),
intval($mypid),
intval($r[0]["id"]));
// Assure that there are no tasks executed twice
$id = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
if (!$id) {
logger("Queue item ".$r[0]["id"]." vanished - skip this execution", LOGGER_DEBUG);
continue;
} elseif ((strtotime($id[0]["executed"]) <= 0) OR ($id[0]["pid"] == 0)) {
logger("Entry for queue item ".$r[0]["id"]." wasn't stored - we better stop here", LOGGER_DEBUG);
return;
} elseif ($id[0]["pid"] != $mypid) {
logger("Queue item ".$r[0]["id"]." is to be executed by process ".$id[0]["pid"]." and not by me (".$mypid.") - 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($funcname)) {
logger("Process ".$mypid." - Prio ".$r[0]["priority"]." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
// For better logging create a new process id for every worker call
// But preserve the old one for the worker
$old_process_id = $a->process_id;
$a->process_id = uniqid("wrk", true);
$funcname($argv, $argc);
$a->process_id = $old_process_id;
if ($cooldown > 0) {
logger("Process ".$mypid." - Prio ".$r[0]["priority"]." - ID ".$r[0]["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
sleep($cooldown);
}
logger("Process ".$mypid." - Prio ".$r[0]["priority"]." - 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");
// Fetch the percentage level where the poller will get active
$maxlevel = get_config("system", "max_connections_level");
if ($maxlevel == 0)
$maxlevel = 75;
if ($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 / $max) * 100;
if ($level >= $maxlevel) {
logger("Maximum level (".$maxlevel."%) 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 / $max * 100;
if ($level < $maxlevel)
return false;
logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
return true;
}
/**
* @brief fix the queue entry if the worker process died
*
*/
function poller_kill_stale_workers() {
$r = q("SELECT `pid`, `executed`, `priority`, `parameter` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
if (!dbm::is_result($r)) {
// 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($pid["pid"]));
else {
// Kill long running processes
// Check if the priority is in a valid range
if (!in_array($pid["priority"], array(PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE)))
$pid["priority"] = PRIORITY_MEDIUM;
// Define the maximum durations
$max_duration_defaults = array(PRIORITY_CRITICAL => 360, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 360);
$max_duration = $max_duration_defaults[$pid["priority"]];
$argv = json_decode($pid["parameter"]);
$argv[0] = basename($argv[0]);
// How long is the process already running?
$duration = (time() - strtotime($pid["executed"])) / 60;
if ($duration > $max_duration) {
logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
posix_kill($pid["pid"], SIGTERM);
// We killed the stale process.
// To avoid a blocking situation we reschedule the process at the beginning of the queue.
// Additionally we are lowering the priority.
q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `created` = '%s',
`priority` = %d, `pid` = 0 WHERE `pid` = %d",
dbesc(datetime_convert()),
intval(PRIORITY_NEGLIGIBLE),
intval($pid["pid"]));
} else
logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
}
}
function poller_too_much_workers() {
$queues = get_config("system", "worker_queues");
if ($queues == 0)
$queues = 4;
$maxqueues = $queues;
$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));
$s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00'");
$entries = $s[0]["total"];
if (Config::get("system", "worker_fastlane", false) AND ($queues > 0) AND ($entries > 0) AND ($active >= $queues)) {
$s = q("SELECT `priority` FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `priority` LIMIT 1");
$top_priority = $s[0]["priority"];
$s = q("SELECT `id` FROM `workerqueue` WHERE `priority` <= %d AND `executed` != '0000-00-00 00:00:00' LIMIT 1",
intval($top_priority));
$high_running = dbm::is_result($s);
if (!$high_running AND ($top_priority > PRIORITY_UNDEFINED) AND ($top_priority < PRIORITY_NEGLIGIBLE)) {
logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
$queues = $active + 1;
}
}
// Create a list of queue entries grouped by their priority
$running = array(PRIORITY_CRITICAL => 0,
PRIORITY_HIGH => 0,
PRIORITY_MEDIUM => 0,
PRIORITY_LOW => 0,
PRIORITY_NEGLIGIBLE => 0);
$r = q("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` GROUP BY `priority`");
if (dbm::is_result($r))
foreach ($r AS $process)
$running[$process["priority"]] = $process["running"];
$processlist = "";
$r = q("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` GROUP BY `priority`");
if (dbm::is_result($r))
foreach ($r as $entry) {
if ($processlist != "")
$processlist .= ", ";
$processlist .= $entry["priority"].":".$running[$entry["priority"]]."/".$entry["entries"];
}
logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries." (".$processlist.") - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
// Are there fewer workers running as possible? Then fork a new one.
if (!get_config("system", "worker_dont_fork") AND ($queues > ($active + 1)) AND ($entries > 1)) {
logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
$args = array("php", "include/poller.php", "no_cron");
$a = get_app();
$a->proc_run($args);
}
}
return($active >= $queues);
}
function poller_active_workers() {
$workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'poller.php'");
return($workers[0]["processes"]);
}
/**
* @brief Check if we should pass some slow processes
*
* When the active processes of the highest priority are using more than 2/3
* of all processes, we let pass slower processes.
*
* @param string $highest_priority Returns the currently highest priority
* @return bool We let pass a slower process than $highest_priority
*/
function poller_passing_slow(&$highest_priority) {
$highest_priority = 0;
$r = q("SELECT `priority`
FROM `process`
INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
WHERE `process`.`command` = 'poller.php'");
// No active processes at all? Fine
if (!dbm::is_result($r))
return(false);
$priorities = array();
foreach ($r AS $line)
$priorities[] = $line["priority"];
// Should not happen
if (count($priorities) == 0)
return(false);
$highest_priority = min($priorities);
// The highest process is already the slowest one?
// Then we quit
if ($highest_priority == PRIORITY_NEGLIGIBLE)
return(false);
$high = 0;
foreach ($priorities AS $priority)
if ($priority == $highest_priority)
++$high;
logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
$passing_slow = (($high/count($priorities)) > (2/3));
if ($passing_slow)
logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
return($passing_slow);
}
/**
* @brief Returns the next worker process
*
* @return string SQL statement
*/
function poller_worker_process() {
// Check if we should pass some low priority process
$highest_priority = 0;
if (poller_passing_slow($highest_priority)) {
// Are there waiting processes with a higher priority than the currently highest?
$r = q("SELECT * FROM `workerqueue`
WHERE `executed` = '0000-00-00 00:00:00' AND `priority` < %d
ORDER BY `priority`, `created` LIMIT 1", dbesc($highest_priority));
if (dbm::is_result($r))
return $r;
// Give slower processes some processing time
$r = q("SELECT * FROM `workerqueue`
WHERE `executed` = '0000-00-00 00:00:00' AND `priority` > %d
ORDER BY `priority`, `created` LIMIT 1", dbesc($highest_priority));
}
// If there is no result (or we shouldn't pass lower processes) we check without priority limit
if (($highest_priority == 0) OR !dbm::is_result($r))
$r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `priority`, `created` LIMIT 1");
return $r;
}
if (array_search(__file__,get_included_files())===0){
poller_run($_SERVER["argv"],$_SERVER["argc"]);
get_app()->end_process();
killme();
}
?>