From df337e57d130ceb370e5269f0052254c873b27a5 Mon Sep 17 00:00:00 2001
From: Michael Vogel <icarus@dabo.de>
Date: Fri, 3 Jun 2016 23:10:23 +0200
Subject: [PATCH] Quit when processlist is too long

---
 include/dbm.php    |  4 +++-
 include/poller.php | 14 ++++++++++----
 index.php          | 10 ++++++++--
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/include/dbm.php b/include/dbm.php
index f68987c235..1e1c3706e0 100644
--- a/include/dbm.php
+++ b/include/dbm.php
@@ -15,12 +15,14 @@ class dbm {
 		// updating
 
 		$statelist = "";
+		$processes = 0;
 		foreach ($states AS $state => $usage) {
 			if ($statelist != "")
 				$statelist .= ", ";
 			$statelist .= $state.": ".$usage;
+			++$processes;
 		}
-		return($statelist);
+		return(array("list" => $statelist, "amount" => $processes));
 	}
 }
 ?>
diff --git a/include/poller.php b/include/poller.php
index 714d4c537c..45dc332e17 100644
--- a/include/poller.php
+++ b/include/poller.php
@@ -28,8 +28,11 @@ function poller_run(&$argv, &$argc){
 	};
 
 	$processlist = dbm::processlist();
-	if ($processlist != "")
-		logger("Processlist: ".$processlist, LOGGER_DEBUG);
+	if ($processlist["list"] != "") {
+		logger("Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
+		if ($processlist["amount"] > 5)
+			return;
+	}
 
 	if (poller_max_connections_reached())
 		return;
@@ -66,8 +69,11 @@ function poller_run(&$argv, &$argc){
 
 		// Log the type of database processes
 		$processlist = dbm::processlist();
-		if ($processlist != "")
-			logger("Processlist: ".$processlist, LOGGER_DEBUG);
+		if ($processlist["amount"] != "") {
+			logger("Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
+			if ($processlist["amount"] > 5)
+				return;
+		}
 
 		// Constantly check the number of available database connections to let the frontend be accessible at any time
 		if (poller_max_connections_reached())
diff --git a/index.php b/index.php
index ec72771341..a25c6dc776 100644
--- a/index.php
+++ b/index.php
@@ -55,8 +55,14 @@ if(!$install) {
 	load_config('system');
 
 	$processlist = dbm::processlist();
-	if ($processlist != "")
-		logger("Processlist: ".$processlist, LOGGER_DEBUG);
+	if ($processlist["list"] != "") {
+		logger("Processes: ".$processlist["amount"]." - Processlist: ".$processlist["list"], LOGGER_DEBUG);
+
+		// More than 20 running database processes?
+		// The system is too busy, so quit.
+		if ($processlist["amount"] > 20)
+			system_unavailable();
+	}
 
 	$maxsysload_frontend = intval(get_config('system','maxloadavg_frontend'));
 	if($maxsysload_frontend < 1)