Poller: Check the number of used database connections

[friendica.git] / include / poller.php

diff --git a/include/poller.php b/include/poller.php
index 190f3fb1ad50f2985ed583cc8ef8588ada309814..712f6d5788da8b1f7272b0c9e2c62c1387a8d9b0 100644 (file)
--- a/include/poller.php
+++ b/include/poller.php
@@ -26,6 +26,9 @@ function poller_run(&$argv, &$argc){
                unset($db_host, $db_user, $db_pass, $db_data);
        };
 
+       if (poller_max_connections_reached())
+               return;
+
        $load = current_load();
        if($load) {
                $maxsysload = intval(get_config('system','maxloadavg'));
@@ -117,6 +120,40 @@ function poller_run(&$argv, &$argc){
 
 }
 
+/**
+ * @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() {
+       $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
+       if (!$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;
+
+       $connected = intval($r[0]["Value"]);
+       if ($connected == 0)
+               return false;
+
+       $level = $connected / $max;
+
+       logger("Connection usage: ".$connected."/".$max, LOGGER_DEBUG);
+
+       if ($level < (3/4))
+               return false;
+
+       logger("Maximum level (3/4) of connections reached: ".$connected."/".$max);
+       return true;
+
+}
+
 /**
  * @brief fix the queue entry if the worker process died
  *