Friendica Communications Platform (please note that this is a clone of the repository at github, issues are handled there) https://friendi.ca
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<?php
/**
* @file src/Core/Worker.php
*/
namespace Friendica\Core;
use Friendica\BaseObject;
use Friendica\Core\Logger;
use Friendica\Database\DBA;
use Friendica\Model\Process;
use Friendica\Util\DateTimeFormat;
use Friendica\Util\Network;
/**
* @file src/Core/Worker.php
*
* @brief Contains the class for the worker background job processing
*/
/**
* @brief Worker methods
*/
class Worker
{
private static $up_start;
private static $db_duration;
private static $last_update;
private static $lock_duration;
/**
* @brief Processes the tasks that are in the workerqueue table
*
* @param boolean $run_cron Should the cron processes be executed?
* @return void
*/
public static function processQueue($run_cron = true)
{
$a = get_app();
self::$up_start = microtime(true);
// At first check the maximum load. We shouldn't continue with a high load
if ($a->isMaxLoadReached()) {
Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
return;
}
// We now start the process. This is done after the load check since this could increase the load.
self::startProcess();
// Kill stale processes every 5 minutes
$last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
if (time() > ($last_cleanup + 300)) {
Config::set('system', 'worker_last_cleaned', time());
self::killStaleWorkers();
}
// Count active workers and compare them with a maximum value that depends on the load
if (self::tooMuchWorkers()) {
Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
return;
}
// Do we have too few memory?
if ($a->isMinMemoryReached()) {
Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
return;
}
// Possibly there are too much database connections
if (self::maxConnectionsReached()) {
Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
return;
}
// Possibly there are too much database processes that block the system
if ($a->isMaxProcessesReached()) {
Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
return;
}
// Now we start additional cron processes if we should do so
if ($run_cron) {
self::runCron();
}
$starttime = time();
// We fetch the next queue entry that is about to be executed
while ($r = self::workerProcess($passing_slow)) {
// When we are processing jobs with a lower priority, we don't refetch new jobs
// Otherwise fast jobs could wait behind slow ones and could be blocked.
$refetched = $passing_slow;
foreach ($r as $entry) {
// Assure that the priority is an integer value
$entry['priority'] = (int)$entry['priority'];
// The work will be done
if (!self::execute($entry)) {
Logger::log('Process execution failed, quitting.', Logger::DEBUG);
return;
}
// If possible we will fetch new jobs for this worker
if (!$refetched && Lock::acquire('worker_process', 0)) {
$stamp = (float)microtime(true);
$refetched = self::findWorkerProcesses($passing_slow);
self::$db_duration += (microtime(true) - $stamp);
Lock::release('worker_process');
}
}
// To avoid the quitting of multiple workers only one worker at a time will execute the check
if (Lock::acquire('worker', 0)) {
$stamp = (float)microtime(true);
// Count active workers and compare them with a maximum value that depends on the load
if (self::tooMuchWorkers()) {
Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
Lock::release('worker');
return;
}
// Check free memory
if ($a->isMinMemoryReached()) {
Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
Lock::release('worker');
return;
}
Lock::release('worker');
self::$db_duration += (microtime(true) - $stamp);
}
// Quit the worker once every 5 minutes
if (time() > ($starttime + 300)) {
Logger::log('Process lifetime reached, quitting.', Logger::DEBUG);
return;
}
}
// Cleaning up. Possibly not needed, but it doesn't harm anything.
if (Config::get('system', 'worker_daemon_mode', false)) {
self::IPCSetJobState(false);
}
Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
}
/**
* @brief Returns the number of deferred entries in the worker queue
*
* @return integer Number of deferred entries in the worker queue
*/
private static function deferredEntries()
{
return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` > ?",
DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
}
/**
* @brief Returns the number of non executed entries in the worker queue
*
* @return integer Number of non executed entries in the worker queue
*/
private static function totalEntries()
{
return DBA::count('workerqueue', ["`executed` <= ? AND NOT `done` AND `next_try` < ?",
DBA::NULL_DATETIME, DateTimeFormat::utcNow()]);
}
/**
* @brief Returns the highest priority in the worker queue that isn't executed
*
* @return integer Number of active worker processes
*/
private static function highestPriority()
{
$condition = ["`executed` <= ? AND NOT `done` AND `next_try` < ?", DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
$workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
if (DBA::isResult($workerqueue)) {
return $workerqueue["priority"];
} else {
return 0;
}
}
/**
* @brief Returns if a process with the given priority is running
*
* @param integer $priority The priority that should be checked
*
* @return integer Is there a process running with that priority?
*/
private static function processWithPriorityActive($priority)
{
$condition = ["`priority` <= ? AND `executed` > ? AND NOT `done` AND `next_try` < ?",
$priority, DBA::NULL_DATETIME, DateTimeFormat::utcNow()];
return DBA::exists('workerqueue', $condition);
}
/**
* @brief Execute a worker entry
*
* @param array $queue Workerqueue entry
*
* @return boolean "true" if further processing should be stopped
*/
public static function execute($queue)
{
$a = get_app();
$mypid = getmypid();
// Quit when in maintenance
if (Config::get('system', 'maintenance', false, true)) {
Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
return false;
}
// Constantly check the number of parallel database processes
if ($a->isMaxProcessesReached()) {
Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
return false;
}
// Constantly check the number of available database connections to let the frontend be accessible at any time
if (self::maxConnectionsReached()) {
Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
return false;
}
$argv = json_decode($queue["parameter"], true);
// Check for existance and validity of the include file
$include = $argv[0];
if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
// We constantly update the "executed" date every minute to avoid being killed too soon
if (!isset(self::$last_update)) {
self::$last_update = strtotime($queue["executed"]);
}
$age = (time() - self::$last_update) / 60;
self::$last_update = time();
if ($age > 1) {
$stamp = (float)microtime(true);
DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
self::$db_duration += (microtime(true) - $stamp);
}
array_shift($argv);
self::execFunction($queue, $include, $argv, true);
$stamp = (float)microtime(true);
$condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
if (DBA::update('workerqueue', ['done' => true], $condition)) {
Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
}
self::$db_duration = (microtime(true) - $stamp);
return true;
}
// The script could be provided as full path or only with the function name
if ($include == basename($include)) {
$include = "include/".$include.".php";
}
if (!validate_include($include)) {
Logger::log("Include file ".$argv[0]." is not valid!");
DBA::delete('workerqueue', ['id' => $queue["id"]]);
return true;
}
require_once $include;
$funcname = str_replace(".php", "", basename($argv[0]))."_run";
if (function_exists($funcname)) {
// We constantly update the "executed" date every minute to avoid being killed too soon
if (!isset(self::$last_update)) {
self::$last_update = strtotime($queue["executed"]);
}
$age = (time() - self::$last_update) / 60;
self::$last_update = time();
if ($age > 1) {
$stamp = (float)microtime(true);
DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
self::$db_duration += (microtime(true) - $stamp);
}
self::execFunction($queue, $funcname, $argv, false);
$stamp = (float)microtime(true);
if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
}
self::$db_duration = (microtime(true) - $stamp);
} else {
Logger::log("Function ".$funcname." does not exist");
DBA::delete('workerqueue', ['id' => $queue["id"]]);
}
return true;
}
/**
* @brief Execute a function from the queue
*
* @param array $queue Workerqueue entry
* @param string $funcname name of the function
* @param array $argv Array of values to be passed to the function
* @param boolean $method_call boolean
* @return void
*/
private static function execFunction($queue, $funcname, $argv, $method_call)
{
$a = get_app();
$mypid = getmypid();
$argc = count($argv);
$new_process_id = System::processID("wrk");
Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
$stamp = (float)microtime(true);
// We use the callstack here to analyze the performance of executed worker entries.
// For this reason the variables have to be initialized.
if (Config::get("system", "profiler")) {
$a->performance["start"] = microtime(true);
$a->performance["database"] = 0;
$a->performance["database_write"] = 0;
$a->performance["cache"] = 0;
$a->performance["cache_write"] = 0;
$a->performance["network"] = 0;
$a->performance["file"] = 0;
$a->performance["rendering"] = 0;
$a->performance["parser"] = 0;
$a->performance["marktime"] = 0;
$a->performance["markstart"] = microtime(true);
$a->callstack = [];
}
// 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 = $new_process_id;
$a->queue = $queue;
$up_duration = number_format(microtime(true) - self::$up_start, 3);
// Reset global data to avoid interferences
unset($_SESSION);
if ($method_call) {
call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
} else {
$funcname($argv, $argc);
}
$a->process_id = $old_process_id;
unset($a->queue);
$duration = (microtime(true) - $stamp);
self::$up_start = microtime(true);
/* With these values we can analyze how effective the worker is.
* The database and rest time should be low since this is the unproductive time.
* The execution time is the productive time.
* By changing parameters like the maximum number of workers we can check the effectivness.
*/
Logger::log(
'DB: '.number_format(self::$db_duration, 2).
' - Lock: '.number_format(self::$lock_duration, 2).
' - Rest: '.number_format($up_duration - self::$db_duration - self::$lock_duration, 2).
' - Execution: '.number_format($duration, 2),
Logger::DEBUG
);
self::$lock_duration = 0;
if ($duration > 3600) {
Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", Logger::DEBUG);
} elseif ($duration > 600) {
Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", Logger::DEBUG);
} elseif ($duration > 300) {
Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", Logger::DEBUG);
} elseif ($duration > 120) {
Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", Logger::DEBUG);
}
Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds. Process PID: ".$new_process_id);
// Write down the performance values into the log
if (Config::get("system", "profiler")) {
$duration = microtime(true)-$a->performance["start"];
$o = '';
if (Config::get("rendertime", "callstack")) {
if (isset($a->callstack["database"])) {
$o .= "\nDatabase Read:\n";
foreach ($a->callstack["database"] as $func => $time) {
$time = round($time, 3);
if ($time > 0) {
$o .= $func.": ".$time."\n";
}
}
}
if (isset($a->callstack["database_write"])) {
$o .= "\nDatabase Write:\n";
foreach ($a->callstack["database_write"] as $func => $time) {
$time = round($time, 3);
if ($time > 0) {
$o .= $func.": ".$time."\n";
}
}
}
if (isset($a->callstack["dache"])) {
$o .= "\nCache Read:\n";
foreach ($a->callstack["dache"] as $func => $time) {
$time = round($time, 3);
if ($time > 0) {
$o .= $func.": ".$time."\n";
}
}
}
if (isset($a->callstack["dache_write"])) {
$o .= "\nCache Write:\n";
foreach ($a->callstack["dache_write"] as $func => $time) {
$time = round($time, 3);
if ($time > 0) {
$o .= $func.": ".$time."\n";
}
}
}
if (isset($a->callstack["network"])) {
$o .= "\nNetwork:\n";
foreach ($a->callstack["network"] as $func => $time) {
$time = round($time, 3);
if ($time > 0) {
$o .= $func.": ".$time."\n";
}
}
}
}
Logger::log(
"ID ".$queue["id"].": ".$funcname.": ".sprintf(
"DB: %s/%s, Cache: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
number_format($a->performance["database"] - $a->performance["database_write"], 2),
number_format($a->performance["database_write"], 2),
number_format($a->performance["cache"], 2),
number_format($a->performance["cache_write"], 2),
number_format($a->performance["network"], 2),
number_format($a->performance["file"], 2),
number_format($duration - ($a->performance["database"]
+ $a->performance["cache"] + $a->performance["cache_write"]
+ $a->performance["network"] + $a->performance["file"]), 2),
number_format($duration, 2)
),
Logger::DEBUG
);
}
$cooldown = Config::get("system", "worker_cooldown", 0);
if ($cooldown > 0) {
Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
sleep($cooldown);
}
}
/**
* @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?
*/
private static function maxConnectionsReached()
{
// Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
$max = Config::get("system", "max_connections");
// Fetch the percentage level where the worker will get active
$maxlevel = Config::get("system", "max_connections_level", 75);
if ($max == 0) {
// the maximum number of possible user connections can be a system variable
$r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
if (DBA::isResult($r)) {
$max = $r["Value"];
}
// Or it can be granted. This overrides the system variable
$r = DBA::p('SHOW GRANTS');
while ($grants = DBA::fetch($r)) {
$grant = array_pop($grants);
if (stristr($grant, "GRANT USAGE ON")) {
if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
$max = $match[1];
}
}
}
DBA::close($r);
}
// 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 = DBA::p('SHOW PROCESSLIST');
$used = DBA::numRows($r);
DBA::close($r);
Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
$level = ($used / $max) * 100;
if ($level >= $maxlevel) {
Logger::log("Maximum level (".$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.
$r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
if (!DBA::isResult($r)) {
return false;
}
$max = intval($r["Value"]);
if ($max == 0) {
return false;
}
$r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
if (!DBA::isResult($r)) {
return false;
}
$used = intval($r["Value"]);
if ($used == 0) {
return false;
}
Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
$level = $used / $max * 100;
if ($level < $maxlevel) {
return false;
}
Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
return true;
}
/**
* @brief fix the queue entry if the worker process died
* @return void
*/
private static function killStaleWorkers()
{
$entries = DBA::select(
'workerqueue',
['id', 'pid', 'executed', 'priority', 'parameter'],
['`executed` > ? AND NOT `done` AND `pid` != 0', DBA::NULL_DATETIME],
['order' => ['priority', 'created']]
);
while ($entry = DBA::fetch($entries)) {
if (!posix_kill($entry["pid"], 0)) {
DBA::update(
'workerqueue',
['executed' => DBA::NULL_DATETIME, 'pid' => 0],
['id' => $entry["id"]]
);
} else {
// Kill long running processes
// Check if the priority is in a valid range
if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
$entry["priority"] = PRIORITY_MEDIUM;
}
// Define the maximum durations
$max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
$max_duration = $max_duration_defaults[$entry["priority"]];
$argv = json_decode($entry["parameter"], true);
$argv[0] = basename($argv[0]);
// How long is the process already running?
$duration = (time() - strtotime($entry["executed"])) / 60;
if ($duration > $max_duration) {
Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
posix_kill($entry["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. (But not PRIORITY_CRITICAL)
$new_priority = $entry["priority"];
if ($entry["priority"] == PRIORITY_HIGH) {
$new_priority = PRIORITY_MEDIUM;
} elseif ($entry["priority"] == PRIORITY_MEDIUM) {
$new_priority = PRIORITY_LOW;
} elseif ($entry["priority"] != PRIORITY_CRITICAL) {
$new_priority = PRIORITY_NEGLIGIBLE;
}
DBA::update(
'workerqueue',
['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
['id' => $entry["id"]]
);
} else {
Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
}
}
}
}
/**
* @brief Checks if the number of active workers exceeds the given limits
*
* @return bool Are there too much workers running?
*/
public static function tooMuchWorkers()
{
$queues = Config::get("system", "worker_queues", 4);
$maxqueues = $queues;
$active = self::activeWorkers();
// Decrease the number of workers at higher load
$load = System::currentLoad();
if ($load) {
$maxsysload = intval(Config::get("system", "maxloadavg", 50));
/* Default exponent 3 causes queues to rapidly decrease as load increases.
* If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
* For some environments, this rapid decrease is not needed.
* With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
*/
$exponent = intval(Config::get('system', 'worker_load_exponent', 3));
$slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
$queues = intval(ceil($slope * $maxqueues));
$processlist = '';
if (Config::get('system', 'worker_debug')) {
// Create a list of queue entries grouped by their priority
$listitem = [];
// Adding all processes with no workerqueue entry
$processes = DBA::p(
"SELECT COUNT(*) AS `running` FROM `process` WHERE NOT EXISTS
(SELECT id FROM `workerqueue`
WHERE `workerqueue`.`pid` = `process`.`pid` AND NOT `done` AND `pid` != ?)",
getmypid()
);
if ($process = DBA::fetch($processes)) {
$listitem[0] = "0:".$process["running"];
}
DBA::close($processes);
// Now adding all processes with workerqueue entries
$entries = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` AND `next_try` < ? GROUP BY `priority`", DateTimeFormat::utcNow());
while ($entry = DBA::fetch($entries)) {
$processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `next_try` < ? AND `priority` = ?",
DateTimeFormat::utcNow(), $entry["priority"]);
if ($process = DBA::fetch($processes)) {
$listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
}
DBA::close($processes);
}
DBA::close($entries);
$intervals = [1, 10, 60];
$jobs_per_minute = [];
foreach ($intervals as $interval) {
$jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ".intval($interval)." MINUTE");
if ($job = DBA::fetch($jobs)) {
$jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
}
DBA::close($jobs);
}
$processlist = ' - jpm: '.implode('/', $jobs_per_minute).' ('.implode(', ', $listitem).')';
}
$entries = self::totalEntries();
$deferred = self::deferredEntries();
if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($active >= $queues)) {
$top_priority = self::highestPriority();
$high_running = self::processWithPriorityActive($top_priority);
if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
$queues = $active + 1;
}
}
Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $entries . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
// Are there fewer workers running as possible? Then fork a new one.
if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && ($entries > 1)) {
Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
if (Config::get('system', 'worker_daemon_mode', false)) {
self::IPCSetJobState(true);
} else {
self::spawnWorker();
}
}
}
// if there are too much worker, we don't spawn a new one.
if (Config::get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
self::IPCSetJobState(false);
}
return $active > $queues;
}
/**
* @brief Returns the number of active worker processes
*
* @return integer Number of active worker processes
*/
private static function activeWorkers()
{
return DBA::count('process', ['command' => 'Worker.php']);
}
/**
* @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 $highest_priority
*/
private static function passingSlow(&$highest_priority)
{
$highest_priority = 0;
$r = DBA::p(
"SELECT `priority`
FROM `process`
INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done`"
);
// No active processes at all? Fine
if (!DBA::isResult($r)) {
return false;
}
$priorities = [];
while ($line = DBA::fetch($r)) {
$priorities[] = $line["priority"];
}
DBA::close($r);
// 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::log("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::log("Passing slower processes than priority ".$highest_priority, Logger::DEBUG);
}
return $passing_slow;
}
/**
* @brief Find and claim the next worker process for us
*
* @param boolean $passing_slow Returns if we had passed low priority processes
* @return boolean Have we found something?
*/
private static function findWorkerProcesses(&$passing_slow)
{
$mypid = getmypid();
// Check if we should pass some low priority process
$highest_priority = 0;
$found = false;
$passing_slow = false;
// The higher the number of parallel workers, the more we prefetch to prevent concurring access
// We decrease the limit with the number of entries left in the queue
$worker_queues = Config::get("system", "worker_queues", 4);
$queue_length = Config::get('system', 'worker_fetch_limit', 1);
$lower_job_limit = $worker_queues * $queue_length * 2;
$jobs = self::totalEntries();
$deferred = self::deferredEntries();
// Now do some magic
$exponent = 2;
$slope = $queue_length / pow($lower_job_limit, $exponent);
$limit = min($queue_length, ceil($slope * pow($jobs, $exponent)));
Logger::log('Deferred: ' . $deferred . ' - Total: ' . $jobs . ' - Maximum: ' . $queue_length . ' - jobs per queue: ' . $limit, Logger::DEBUG);
$ids = [];
if (self::passingSlow($highest_priority)) {
// Are there waiting processes with a higher priority than the currently highest?
$result = DBA::select(
'workerqueue',
['id'],
["`executed` <= ? AND `priority` < ? AND NOT `done` AND `next_try` < ?",
DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
['limit' => $limit, 'order' => ['priority', 'created']]
);
while ($id = DBA::fetch($result)) {
$ids[] = $id["id"];
}
DBA::close($result);
$found = (count($ids) > 0);
if (!$found) {
// Give slower processes some processing time
$result = DBA::select(
'workerqueue',
['id'],
["`executed` <= ? AND `priority` > ? AND NOT `done` AND `next_try` < ?",
DBA::NULL_DATETIME, $highest_priority, DateTimeFormat::utcNow()],
['limit' => $limit, 'order' => ['priority', 'created']]
);
while ($id = DBA::fetch($result)) {
$ids[] = $id["id"];
}
DBA::close($result);
$found = (count($ids) > 0);
$passing_slow = $found;
}
}
// If there is no result (or we shouldn't pass lower processes) we check without priority limit
if (!$found) {
$result = DBA::select(
'workerqueue',
['id'],
["`executed` <= ? AND NOT `done` AND `next_try` < ?",
DBA::NULL_DATETIME, DateTimeFormat::utcNow()],
['limit' => $limit, 'order' => ['priority', 'created']]
);
while ($id = DBA::fetch($result)) {
$ids[] = $id["id"];
}
DBA::close($result);
$found = (count($ids) > 0);
}
if ($found) {
$condition = "`id` IN (".substr(str_repeat("?, ", count($ids)), 0, -2).") AND `pid` = 0 AND NOT `done`";
array_unshift($ids, $condition);
DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $ids);
}
return $found;
}
/**
* @brief Returns the next worker process
*
* @param boolean $passing_slow Returns if we had passed low priority processes
* @return string SQL statement
*/
public static function workerProcess(&$passing_slow)
{
$stamp = (float)microtime(true);
// There can already be jobs for us in the queue.
$r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
if (DBA::isResult($r)) {
self::$db_duration += (microtime(true) - $stamp);
return DBA::toArray($r);
}
DBA::close($r);
$stamp = (float)microtime(true);
if (!Lock::acquire('worker_process')) {
return false;
}
self::$lock_duration = (microtime(true) - $stamp);
$stamp = (float)microtime(true);
$found = self::findWorkerProcesses($passing_slow);
self::$db_duration += (microtime(true) - $stamp);
Lock::release('worker_process');
if ($found) {
$r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
return DBA::toArray($r);
}
return false;
}
/**
* @brief Removes a workerqueue entry from the current process
* @return void
*/
public static function unclaimProcess()
{
$mypid = getmypid();
DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
}
/**
* @brief Call the front end worker
* @return void
*/
public static function callWorker()
{
if (!Config::get("system", "frontend_worker")) {
return;
}
$url = System::baseUrl()."/worker";
Network::fetchUrl($url, false, $redirects, 1);
}
/**
* @brief Call the front end worker if there aren't any active
* @return void
*/
public static function executeIfIdle()
{
if (!Config::get("system", "frontend_worker")) {
return;
}
// Do we have "proc_open"? Then we can fork the worker
if (function_exists("proc_open")) {
// When was the last time that we called the worker?
// Less than one minute? Then we quit
if ((time() - Config::get("system", "worker_started")) < 60) {
return;
}
Config::set("system", "worker_started", time());
// Do we have enough running workers? Then we quit here.
if (self::tooMuchWorkers()) {
// Cleaning dead processes
self::killStaleWorkers();
Process::deleteInactive();
return;
}
self::runCron();
Logger::log('Call worker', Logger::DEBUG);
self::spawnWorker();
return;
}
// We cannot execute background processes.
// We now run the processes from the frontend.
// This won't work with long running processes.
self::runCron();
self::clearProcesses();
$workers = self::activeWorkers();
if ($workers == 0) {
self::callWorker();
}
}
/**
* @brief Removes long running worker processes
* @return void
*/
public static function clearProcesses()
{
$timeout = Config::get("system", "frontend_worker_timeout", 10);
/// @todo We should clean up the corresponding workerqueue entries as well
$condition = ["`created` < ? AND `command` = 'worker.php'",
DateTimeFormat::utc("now - ".$timeout." minutes")];
DBA::delete('process', $condition);
}
/**
* @brief Runs the cron processes
* @return void
*/
private static function runCron()
{
Logger::log('Add cron entries', Logger::DEBUG);
// Check for spooled items
self::add(PRIORITY_HIGH, "SpoolPost");
// Run the cron job that calls all other jobs
self::add(PRIORITY_MEDIUM, "Cron");
// Cleaning dead processes
self::killStaleWorkers();
}
/**
* @brief Spawns a new worker
* @return void
*/
public static function spawnWorker($do_cron = false)
{
$command = 'bin/worker.php';
$args = ['no_cron' => !$do_cron];
get_app()->proc_run($command, $args);
// after spawning we have to remove the flag.
if (Config::get('system', 'worker_daemon_mode', false)) {
self::IPCSetJobState(false);
}
}
/**
* @brief Adds tasks to the worker queue
*
* @param (integer|array) priority or parameter array, strings are deprecated and are ignored
*
* next args are passed as $cmd command line
* or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
* or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
*
* @note $cmd and string args are surrounded with ""
*
* @hooks 'proc_run'
* array $arr
*
* @return boolean "false" if proc_run couldn't be executed
*/
public static function add($cmd)
{
$args = func_get_args();
if (!count($args)) {
return false;
}
$arr = ['args' => $args, 'run_cmd' => true];
Addon::callHooks("proc_run", $arr);
if (!$arr['run_cmd'] || !count($args)) {
return true;
}
$priority = PRIORITY_MEDIUM;
$dont_fork = Config::get("system", "worker_dont_fork", false);
$created = DateTimeFormat::utcNow();
$run_parameter = array_shift($args);
if (is_int($run_parameter)) {
$priority = $run_parameter;
} elseif (is_array($run_parameter)) {
if (isset($run_parameter['priority'])) {
$priority = $run_parameter['priority'];
}
if (isset($run_parameter['created'])) {
$created = $run_parameter['created'];
}
if (isset($run_parameter['dont_fork'])) {
$dont_fork = $run_parameter['dont_fork'];
}
}
$parameters = json_encode($args);
$found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
// Quit if there was a database error - a precaution for the update process to 3.5.3
if (DBA::errorNo() != 0) {
return false;
}
if (!$found) {
DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
}
// Should we quit and wait for the worker to be called as a cronjob?
if ($dont_fork) {
return true;
}
// If there is a lock then we don't have to check for too much worker
if (!Lock::acquire('worker', 0)) {
return true;
}
// If there are already enough workers running, don't fork another one
$quit = self::tooMuchWorkers();
Lock::release('worker');
if ($quit) {
return true;
}
// We tell the daemon that a new job entry exists
if (Config::get('system', 'worker_daemon_mode', false)) {
// We don't have to set the IPC flag - this is done in "tooMuchWorkers"
return true;
}
// Now call the worker to execute the jobs that we just added to the queue
self::spawnWorker();
return true;
}
/**
* Defers the current worker entry
*/
public static function defer()
{
if (empty(BaseObject::getApp()->queue)) {
return;
}
$queue = BaseObject::getApp()->queue;
$retrial = $queue['retrial'];
$id = $queue['id'];
if ($retrial > 14) {
Logger::log('Id ' . $id . ' had been tried 14 times. We stop now.', Logger::DEBUG);
return;
}
// Calculate the delay until the next trial
$delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
$next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
Logger::log('Defer execution ' . $retrial . ' of id ' . $id . ' to ' . $next, Logger::DEBUG);
$fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0];
DBA::update('workerqueue', $fields, ['id' => $id]);
}
/**
* Log active processes into the "process" table
*
* @brief Log active processes into the "process" table
*/
public static function startProcess()
{
$trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
$command = basename($trace[0]['file']);
Process::deleteInactive();
Process::insert($command);
}
/**
* Remove the active process from the "process" table
*
* @brief Remove the active process from the "process" table
* @return bool
*/
public static function endProcess()
{
return Process::deleteByPid();
}
/**
* Set the flag if some job is waiting
*
* @brief Set the flag if some job is waiting
* @param boolean $jobs Is there a waiting job?
*/
public static function IPCSetJobState($jobs)
{
DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
}
/**
* Checks if some worker job waits to be executed
*
* @brief Checks if some worker job waits to be executed
* @return bool
*/
public static function IPCJobsExists()
{
$row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
// When we don't have a row, no job is running
if (!DBA::isResult($row)) {
return false;
}
return (bool)$row['jobs'];
}
}