Merge pull request #2561 from annando/1606-dbm

Check the maximum number of database processes

doc/htconfig.md

@@ -38,6 +38,8 @@ line to your .htconfig.php:
 * max_connections_level - The maximum level of connections that are allowed to let the poller start. It is a percentage value. Default value is 75.
 * max_contact_queue - Default value is 500.
 * max_batch_queue - Default value is 1000.
+* max_processes_backend - Maximum number of concurrent database processes for background tasks. Default value is 5.
+* max_processes_frontend - Maximum number of concurrent database processes for foreground tasks. Default value is 20.
 * no_oembed (Boolean) - Don't use OEmbed to fetch more information about a link.
 * no_oembed_rich_content (Boolean) - Don't show the rich content (e.g. embedded PDF).
 * no_smilies (Boolean) - Don't show smilies.

include/dbm.php

@@ -0,0 +1,39 @@
+<?php
+/**
+ * @brief This class contain functions for the database management
+ *
+ */
+class dbm {
+	/**
+	 * @brief Return a list of database processes
+	 *
+	 * @return array
+	 *      'list' => List of processes, separated in their different states
+	 *      'amount' => Number of concurrent database processes
+	 */
+	public static function processlist() {
+		$r = q("SHOW PROCESSLIST");
+		$s = array();
+
+		$processes = 0;
+		$states = array();
+		foreach ($r AS $process) {
+			$state = trim($process["State"]);
+
+			// Filter out all idle processes
+			if (!in_array($state, array("", "init", "statistics"))) {
+				++$states[$state];
+				++$processes;
+			}
+		}
+
+		$statelist = "";
+		foreach ($states AS $state => $usage) {
+			if ($statelist != "")
+				$statelist .= ", ";
+			$statelist .= $state.": ".$usage;
+		}
+		return(array("list" => $statelist, "amount" => $processes));
+	}
+}
+?>

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, $db;
@@ -26,6 +27,20 @@ function poller_run(&$argv, &$argc){
 		unset($db_host, $db_user, $db_pass, $db_data);
 	};
 
+	$max_processes = get_config('system', 'max_processes_backend');
+	if (intval($max_processes) == 0)
+		$max_processes = 5;
+
+	$processlist = dbm::processlist();
+	if ($processlist["list"] != "") {
+		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;
+		}
+	}
+
 	if (poller_max_connections_reached())
 		return;
 
@@ -59,6 +74,17 @@ 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;

index.php

@@ -41,6 +41,7 @@ $install = ((file_exists('.htconfig.php') && filesize('.htconfig.php')) ? false
  */
 
 require_once("include/dba.php");
+require_once("include/dbm.php");
 
 if(!$install) {
 	$db = new dba($db_host, $db_user, $db_pass, $db_data, $install);
@@ -53,6 +54,21 @@ if(!$install) {
 	load_config('config');
 	load_config('system');
 
+	$processlist = dbm::processlist();
+	if ($processlist["list"] != "") {
+
+		logger("Processcheck: Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
+
+		$max_processes = get_config('system', 'max_processes_frontend');
+		if (intval($max_processes) == 0)
+			$max_processes = 20;
+
+		if ($processlist["amount"] > $max_processes) {
+			logger("Processcheck: Maximum number of processes for frontend tasks (".$max_processes.") reached.", LOGGER_DEBUG);
+			return;
+		}
+	}
+
 	$maxsysload_frontend = intval(get_config('system','maxloadavg_frontend'));
 	if($maxsysload_frontend < 1)
 		$maxsysload_frontend = 50;