Merge remote-tracking branch 'upstream/develop' into 1606-database

[friendica.git] / include / poller.php

diff --git a/include/poller.php b/include/poller.php
index 712f6d5788da8b1f7272b0c9e2c62c1387a8d9b0..a391ea8c7528f654bd944ca1328ca7e01d86fb5b 100644 (file)
--- a/include/poller.php
+++ b/include/poller.php
@@ -11,6 +11,7 @@ if (!file_exists("boot.php") AND (sizeof($_SERVER["argv"]) != 0)) {
 }
 
 require_once("boot.php");
+require_once("dbm.php");
 
 function poller_run(&$argv, &$argc){
        global $a, $db;
@@ -26,21 +27,26 @@ function poller_run(&$argv, &$argc){
                unset($db_host, $db_user, $db_pass, $db_data);
        };
 
-       if (poller_max_connections_reached())
-               return;
+       $max_processes = get_config('system', 'max_processes_backend');
+       if (intval($max_processes) == 0)
+               $max_processes = 5;
 
-       $load = current_load();
-       if($load) {
-               $maxsysload = intval(get_config('system','maxloadavg'));
-               if($maxsysload < 1)
-                       $maxsysload = 50;
+       $processlist = dbm::processlist();
+       if ($processlist["list"] != "") {
+               logger("Processcheck: Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
 
-               if(intval($load) > $maxsysload) {
-                       logger('system: load ' . $load . ' too high. poller deferred to next scheduled run.');
+               if ($processlist["amount"] > $max_processes) {
+                       logger("Processcheck: Maximum number of processes for backend tasks (".$max_processes.") reached.", LOGGER_DEBUG);
                        return;
                }
        }
 
+       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();
@@ -68,6 +74,21 @@ function poller_run(&$argv, &$argc){
 
        while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
 
+               // Log the type of database processes
+               $processlist = dbm::processlist();
+               if ($processlist["amount"] != "") {
+                       logger("Processcheck: Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
+
+                       if ($processlist["amount"] > $max_processes) {
+                               logger("Processcheck: Maximum number of processes for backend tasks (".$max_processes.") reached.", LOGGER_DEBUG);
+                               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(3))
                        return;
@@ -126,6 +147,53 @@ function poller_run(&$argv, &$argc){
  * @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;
@@ -138,20 +206,19 @@ function poller_max_connections_reached() {
        if (!$r)
                return false;
 
-       $connected = intval($r[0]["Value"]);
-       if ($connected == 0)
+       $used = intval($r[0]["Value"]);
+       if ($used == 0)
                return false;
 
-       $level = $connected / $max;
+       logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 
-       logger("Connection usage: ".$connected."/".$max, LOGGER_DEBUG);
+       $level = $used / $max * 100;
 
-       if ($level < (3/4))
+       if ($level < $maxlevel)
                return false;
 
-       logger("Maximum level (3/4) of connections reached: ".$connected."/".$max);
+       logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
        return true;
-
 }
 
 /**
@@ -160,6 +227,12 @@ function poller_max_connections_reached() {
  */
 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",