Merge pull request #5988 from Icinga/fix/concurrent-checks-limit-cluster

Fix concurrent checks limit while using command_endpoint

doc/06-distributed-monitoring.md

@@ -818,6 +818,10 @@ This mode will force the Icinga 2 node to execute commands remotely on a specifi
 The host/service object configuration is located on the master/satellite and the client only
 needs the CheckCommand object definitions being used there.
 
+Every endpoint has its own remote check queue. The amount of checks executed simultaneously
+can be limited on the endpoint with the `MaxConcurrentChecks` constant defined in [constants.conf](04-configuring-icinga-2.md#constants-conf). Icinga 2 may discard check requests,
+if the remote check queue is full.
+
 ![Icinga 2 Distributed Top Down Command Endpoint](images/distributed-monitoring/icinga2_distributed_top_down_command_endpoint.png)
 
 Advantages:

doc/09-object-types.md

@@ -247,16 +247,14 @@ This configuration object is available as [checker feature](11-cli-commands.md#c
 Example:
 
 ```
-object CheckerComponent "checker" {
-  concurrent_checks = 512
-}
+object CheckerComponent "checker" { }
 ```
 
 Configuration Attributes:
 
   Name                      | Type                  | Description
   --------------------------|-----------------------|----------------------------------
-  concurrent\_checks        | Number                | **Optional.** The maximum number of concurrent checks. Defaults to 512.
+  concurrent\_checks        | Number                | **Optional and deprecated.** The maximum number of concurrent checks. Was replaced by global constant `MaxConcurrentChecks` which will be set if you still use `concurrent_checks`.
 
 ## CheckResultReader <a id="objecttype-checkresultreader"></a>
 

doc/17-language-reference.md

@@ -398,6 +398,7 @@ PlatformKernelVersion|**Read-only.** The version of the operating system kernel,
 BuildCompilerName   |**Read-only.** The name of the compiler Icinga was built with, e.g. "Clang".
 BuildCompilerVersion|**Read-only.** The version of the compiler Icinga was built with, e.g. "7.3.0.7030031".
 BuildHostName       |**Read-only.** The name of the host Icinga was built on, e.g. "acheron".
+MaxConcurrentChecks |**Read-write**. The number of max checks run simultaneously. Defaults to 512.
 
 
 Advanced runtime constants. Please only use them if advised by support or developers.

icinga-app/icinga.cpp

@@ -161,6 +161,7 @@ static int Main()
 	Application::DeclareRLimitStack(Application::GetDefaultRLimitStack());
 #endif /* __linux__ */
 	Application::DeclareConcurrency(std::thread::hardware_concurrency());
+	Application::DeclareMaxConcurrentChecks(Application::GetDefaultMaxConcurrentChecks());
 
 	ScriptGlobal::Set("AttachDebugger", false);
 

lib/base/application.cpp

@@ -1552,6 +1552,48 @@ int Application::GetConcurrency()
 	return ScriptGlobal::Get("Concurrency", &defaultConcurrency);
 }
 
+/**
+ * Sets the max concurrent checks.
+ *
+ * @param maxChecks The new limit.
+ */
+void Application::SetMaxConcurrentChecks(int maxChecks)
+{
+	ScriptGlobal::Set("MaxConcurrentChecks", maxChecks);
+}
+
+/**
+ * Sets the max concurrent checks.
+ *
+ * @param maxChecks The new limit.
+ */
+void Application::DeclareMaxConcurrentChecks(int maxChecks)
+{
+	if (!ScriptGlobal::Exists("MaxConcurrentChecks"))
+		ScriptGlobal::Set("MaxConcurrentChecks", maxChecks);
+}
+
+/**
+ * Retrieves the max concurrent checks.
+ *
+ * @returns The max number of concurrent checks.
+ */
+int Application::GetMaxConcurrentChecks()
+{
+	Value defaultMaxConcurrentChecks = GetDefaultMaxConcurrentChecks();
+	return ScriptGlobal::Get("MaxConcurrentChecks", &defaultMaxConcurrentChecks);
+}
+
+/**
+ * Retrieves the default value for max concurrent checks.
+ *
+ * @returns The default max number of concurrent checks.
+ */
+int Application::GetDefaultMaxConcurrentChecks()
+{
+	return 512;
+}
+
 /**
  * Returns the global thread pool.
  *

lib/base/application.hpp

@@ -146,6 +146,11 @@ public:
 	static int GetConcurrency();
 	static void DeclareConcurrency(int ncpus);
 
+	static int GetMaxConcurrentChecks();
+	static int GetDefaultMaxConcurrentChecks();
+	static void DeclareMaxConcurrentChecks(int maxChecks);
+	static void SetMaxConcurrentChecks(int maxChecks);
+
 	static ThreadPool& GetTP();
 
 	static String GetAppVersion();

lib/checker/checkercomponent.ti

@@ -27,8 +27,14 @@ namespace icinga
 class CheckerComponent : ConfigObject
 {
 	[config] int concurrent_checks {
+		get {{{
+			return Application::GetMaxConcurrentChecks();
+		}}}
+		set {{{
+			Application::SetMaxConcurrentChecks(value);
+		}}}
 		default {{{
-			return 512;
+			return Application::GetDefaultMaxConcurrentChecks();
 		}}}
 	};
 };

lib/icinga/CMakeLists.txt

@@ -49,7 +49,7 @@ set(icinga_SOURCES
   checkcommand.cpp checkcommand.hpp checkcommand-ti.hpp
   checkresult.cpp checkresult.hpp checkresult-ti.hpp
   cib.cpp cib.hpp
-  clusterevents.cpp clusterevents.hpp
+  clusterevents.cpp clusterevents.hpp clusterevents-check.cpp
   command.cpp command.hpp command-ti.hpp
   comment.cpp comment.hpp comment-ti.hpp
   compatutility.cpp compatutility.hpp

lib/icinga/checkable-check.cpp

@@ -42,6 +42,7 @@ boost::signals2::signal<void (const Checkable::Ptr&)> Checkable::OnNextCheckUpda
 
 boost::mutex Checkable::m_StatsMutex;
 int Checkable::m_PendingChecks = 0;
+boost::condition_variable Checkable::m_PendingChecksCV;
 
 CheckCommand::Ptr Checkable::GetCheckCommand() const
 {
@@ -544,6 +545,7 @@ void Checkable::DecreasePendingChecks()
 {
 	boost::mutex::scoped_lock lock(m_StatsMutex);
 	m_PendingChecks--;
+	m_PendingChecksCV.notify_one();
 }
 
 int Checkable::GetPendingChecks()
@@ -551,3 +553,12 @@ int Checkable::GetPendingChecks()
 	boost::mutex::scoped_lock lock(m_StatsMutex);
 	return m_PendingChecks;
 }
+
+void Checkable::AquirePendingCheckSlot(int maxPendingChecks)
+{
+	boost::mutex::scoped_lock lock(m_StatsMutex);
+	while (m_PendingChecks >= maxPendingChecks)
+		m_PendingChecksCV.wait(lock);
+
+	m_PendingChecks++;
+}

lib/icinga/checkable.hpp

@@ -197,6 +197,7 @@ public:
 	static void IncreasePendingChecks();
 	static void DecreasePendingChecks();
 	static int GetPendingChecks();
+	static void AquirePendingCheckSlot(int maxPendingChecks);
 
 	static Object::Ptr GetPrototype();
 
@@ -211,6 +212,7 @@ private:
 
 	static boost::mutex m_StatsMutex;
 	static int m_PendingChecks;
+	static boost::condition_variable m_PendingChecksCV;
 
 	/* Downtimes */
 	std::set<Downtime::Ptr> m_Downtimes;

lib/icinga/cib.cpp

@@ -20,6 +20,7 @@
 #include "icinga/cib.hpp"
 #include "icinga/host.hpp"
 #include "icinga/service.hpp"
+#include "icinga/clusterevents.hpp"
 #include "base/objectlock.hpp"
 #include "base/utility.hpp"
 #include "base/perfdatavalue.hpp"
@@ -305,6 +306,8 @@ void CIB::StatsFunc(const Dictionary::Ptr& status, const Array::Ptr& perfdata) {
 	status->Set("active_service_checks_15min", GetActiveServiceChecksStatistics(60 * 15));
 	status->Set("passive_service_checks_15min", GetPassiveServiceChecksStatistics(60 * 15));
 
+	status->Set("remote_check_queue", ClusterEvents::GetCheckRequestQueueSize());
+
 	CheckableCheckStatistics scs = CalculateServiceCheckStats();
 
 	status->Set("min_latency", scs.min_latency);

lib/icinga/clusterevents-check.cpp

@@ -0,0 +1,225 @@
+/******************************************************************************
+ * Icinga 2                                                                   *
+ * Copyright (C) 2012-2018 Icinga Development Team (https://www.icinga.com/)  *
+ *                                                                            *
+ * This program is free software; you can redistribute it and/or              *
+ * modify it under the terms of the GNU General Public License                *
+ * as published by the Free Software Foundation; either version 2             *
+ * of the License, or (at your option) any later version.                     *
+ *                                                                            *
+ * This program is distributed in the hope that it will be useful,            *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              *
+ * GNU General Public License for more details.                               *
+ *                                                                            *
+ * You should have received a copy of the GNU General Public License          *
+ * along with this program; if not, write to the Free Software Foundation     *
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
+ ******************************************************************************/
+
+#include "icinga/clusterevents.hpp"
+#include "remote/apilistener.hpp"
+#include "base/serializer.hpp"
+#include "base/exception.hpp"
+#include <boost/thread/once.hpp>
+#include <thread>
+
+using namespace icinga;
+
+boost::mutex ClusterEvents::m_Mutex;
+std::deque<std::function<void ()>> ClusterEvents::m_CheckRequestQueue;
+bool ClusterEvents::m_CheckSchedulerRunning;
+int ClusterEvents::m_ChecksExecutedDuringInterval;
+int ClusterEvents::m_ChecksDroppedDuringInterval;
+Timer::Ptr ClusterEvents::m_LogTimer;
+
+void ClusterEvents::RemoteCheckThreadProc()
+{
+	Utility::SetThreadName("Remote Check Scheduler");
+
+	boost::mutex::scoped_lock lock(m_Mutex);
+
+	for(;;) {
+		if (m_CheckRequestQueue.empty())
+			break;
+
+		lock.unlock();
+		Checkable::AquirePendingCheckSlot(Application::GetMaxConcurrentChecks());
+		lock.lock();
+
+		auto callback = m_CheckRequestQueue.front();
+		m_CheckRequestQueue.pop_front();
+		m_ChecksExecutedDuringInterval++;
+		lock.unlock();
+
+		callback();
+		Checkable::DecreasePendingChecks();
+
+		lock.lock();
+	}
+
+	m_CheckSchedulerRunning = false;
+}
+
+void ClusterEvents::EnqueueCheck(const MessageOrigin::Ptr& origin, const Dictionary::Ptr& params)
+{
+	static boost::once_flag once = BOOST_ONCE_INIT;
+
+	boost::call_once(once, []() {
+		m_LogTimer = new Timer();
+		m_LogTimer->SetInterval(10);
+		m_LogTimer->OnTimerExpired.connect(std::bind(ClusterEvents::LogRemoteCheckQueueInformation));
+		m_LogTimer->Start();
+	});
+
+	boost::mutex::scoped_lock lock(m_Mutex);
+
+	if (m_CheckRequestQueue.size() >= 25000) {
+		m_ChecksDroppedDuringInterval++;
+		return;
+	}
+
+	m_CheckRequestQueue.push_back(std::bind(ClusterEvents::ExecuteCheckFromQueue, origin, params));
+
+	if (!m_CheckSchedulerRunning) {
+		std::thread t(ClusterEvents::RemoteCheckThreadProc);
+		t.detach();
+		m_CheckSchedulerRunning = true;
+	}
+}
+
+void ClusterEvents::ExecuteCheckFromQueue(const MessageOrigin::Ptr& origin, const Dictionary::Ptr& params) {
+
+	Endpoint::Ptr sourceEndpoint = origin->FromClient->GetEndpoint();
+
+	if (!sourceEndpoint || (origin->FromZone && !Zone::GetLocalZone()->IsChildOf(origin->FromZone))) {
+		Log(LogNotice, "ClusterEvents")
+				<< "Discarding 'execute command' message from '" << origin->FromClient->GetIdentity() << "': Invalid endpoint origin (client not allowed).";
+		return;
+	}
+
+	ApiListener::Ptr listener = ApiListener::GetInstance();
+
+	if (!listener) {
+		Log(LogCritical, "ApiListener", "No instance available.");
+		return;
+	}
+
+	if (!listener->GetAcceptCommands()) {
+		Log(LogWarning, "ApiListener")
+				<< "Ignoring command. '" << listener->GetName() << "' does not accept commands.";
+
+		Host::Ptr host = new Host();
+		Dictionary::Ptr attrs = new Dictionary();
+
+		attrs->Set("__name", params->Get("host"));
+		attrs->Set("type", "Host");
+		attrs->Set("enable_active_checks", false);
+
+		Deserialize(host, attrs, false, FAConfig);
+
+		if (params->Contains("service"))
+			host->SetExtension("agent_service_name", params->Get("service"));
+
+		CheckResult::Ptr cr = new CheckResult();
+		cr->SetState(ServiceUnknown);
+		cr->SetOutput("Endpoint '" + Endpoint::GetLocalEndpoint()->GetName() + "' does not accept commands.");
+		Dictionary::Ptr message = MakeCheckResultMessage(host, cr);
+		listener->SyncSendMessage(sourceEndpoint, message);
+
+		return;
+	}
+
+	/* use a virtual host object for executing the command */
+	Host::Ptr host = new Host();
+	Dictionary::Ptr attrs = new Dictionary();
+
+	attrs->Set("__name", params->Get("host"));
+	attrs->Set("type", "Host");
+
+	Deserialize(host, attrs, false, FAConfig);
+
+	if (params->Contains("service"))
+		host->SetExtension("agent_service_name", params->Get("service"));
+
+	String command = params->Get("command");
+	String command_type = params->Get("command_type");
+
+	if (command_type == "check_command") {
+		if (!CheckCommand::GetByName(command)) {
+			CheckResult::Ptr cr = new CheckResult();
+			cr->SetState(ServiceUnknown);
+			cr->SetOutput("Check command '" + command + "' does not exist.");
+			Dictionary::Ptr message = MakeCheckResultMessage(host, cr);
+			listener->SyncSendMessage(sourceEndpoint, message);
+			return;
+		}
+	} else if (command_type == "event_command") {
+		if (!EventCommand::GetByName(command)) {
+			Log(LogWarning, "ClusterEvents")
+					<< "Event command '" << command << "' does not exist.";
+			return;
+		}
+	} else
+		return;
+
+	attrs->Set(command_type, params->Get("command"));
+	attrs->Set("command_endpoint", sourceEndpoint->GetName());
+
+	Deserialize(host, attrs, false, FAConfig);
+
+	host->SetExtension("agent_check", true);
+
+	Dictionary::Ptr macros = params->Get("macros");
+
+	if (command_type == "check_command") {
+		try {
+			host->ExecuteRemoteCheck(macros);
+		} catch (const std::exception& ex) {
+			CheckResult::Ptr cr = new CheckResult();
+			cr->SetState(ServiceUnknown);
+
+			String output = "Exception occured while checking '" + host->GetName() + "': " + DiagnosticInformation(ex);
+			cr->SetOutput(output);
+
+			double now = Utility::GetTime();
+			cr->SetScheduleStart(now);
+			cr->SetScheduleEnd(now);
+			cr->SetExecutionStart(now);
+			cr->SetExecutionEnd(now);
+
+			Dictionary::Ptr message = MakeCheckResultMessage(host, cr);
+			listener->SyncSendMessage(sourceEndpoint, message);
+
+			Log(LogCritical, "checker", output);
+		}
+	} else if (command_type == "event_command") {
+		host->ExecuteEventHandler(macros, true);
+	}
+}
+
+int ClusterEvents::GetCheckRequestQueueSize()
+{
+	return m_CheckRequestQueue.size();
+}
+
+void ClusterEvents::LogRemoteCheckQueueInformation() {
+	if (m_ChecksDroppedDuringInterval > 0) {
+		Log(LogCritical, "ClusterEvents")
+			<< "Remote check queue ran out of slots. "
+			<< m_ChecksDroppedDuringInterval << " checks dropped.";
+		m_ChecksDroppedDuringInterval = 0;
+	}
+
+	if (m_ChecksExecutedDuringInterval == 0)
+		return;
+
+	Log(LogInformation, "RemoteCheckQueue")
+		<< "items: " << m_CheckRequestQueue.size()
+		<< ", rate: " << m_ChecksExecutedDuringInterval / 10 << "/s "
+		<< "(" << m_ChecksExecutedDuringInterval * 6 << "/min "
+		<< m_ChecksExecutedDuringInterval * 6 * 5 << "/5min "
+		<< m_ChecksExecutedDuringInterval * 6 * 15 << "/15min" << ");";
+
+	m_ChecksExecutedDuringInterval = 0;
+}

lib/icinga/clusterevents.cpp

@@ -578,112 +578,7 @@ Value ClusterEvents::AcknowledgementClearedAPIHandler(const MessageOrigin::Ptr&
 
 Value ClusterEvents::ExecuteCommandAPIHandler(const MessageOrigin::Ptr& origin, const Dictionary::Ptr& params)
 {
-	Endpoint::Ptr sourceEndpoint = origin->FromClient->GetEndpoint();
-
-	if (!sourceEndpoint || (origin->FromZone && !Zone::GetLocalZone()->IsChildOf(origin->FromZone))) {
-		Log(LogNotice, "ClusterEvents")
-			<< "Discarding 'execute command' message from '" << origin->FromClient->GetIdentity() << "': Invalid endpoint origin (client not allowed).";
-		return Empty;
-	}
-
-	ApiListener::Ptr listener = ApiListener::GetInstance();
-
-	if (!listener) {
-		Log(LogCritical, "ApiListener", "No instance available.");
-		return Empty;
-	}
-
-	if (!listener->GetAcceptCommands()) {
-		Log(LogWarning, "ApiListener")
-			<< "Ignoring command. '" << listener->GetName() << "' does not accept commands.";
-
-		Host::Ptr host = new Host();
-		Dictionary::Ptr attrs = new Dictionary();
-
-		attrs->Set("__name", params->Get("host"));
-		attrs->Set("type", "Host");
-		attrs->Set("enable_active_checks", false);
-
-		Deserialize(host, attrs, false, FAConfig);
-
-		if (params->Contains("service"))
-			host->SetExtension("agent_service_name", params->Get("service"));
-
-		CheckResult::Ptr cr = new CheckResult();
-		cr->SetState(ServiceUnknown);
-		cr->SetOutput("Endpoint '" + Endpoint::GetLocalEndpoint()->GetName() + "' does not accept commands.");
-		Dictionary::Ptr message = MakeCheckResultMessage(host, cr);
-		listener->SyncSendMessage(sourceEndpoint, message);
-
-		return Empty;
-	}
-
-	/* use a virtual host object for executing the command */
-	Host::Ptr host = new Host();
-	Dictionary::Ptr attrs = new Dictionary();
-
-	attrs->Set("__name", params->Get("host"));
-	attrs->Set("type", "Host");
-
-	Deserialize(host, attrs, false, FAConfig);
-
-	if (params->Contains("service"))
-		host->SetExtension("agent_service_name", params->Get("service"));
-
-	String command = params->Get("command");
-	String command_type = params->Get("command_type");
-
-	if (command_type == "check_command") {
-		if (!CheckCommand::GetByName(command)) {
-			CheckResult::Ptr cr = new CheckResult();
-			cr->SetState(ServiceUnknown);
-			cr->SetOutput("Check command '" + command + "' does not exist.");
-			Dictionary::Ptr message = MakeCheckResultMessage(host, cr);
-			listener->SyncSendMessage(sourceEndpoint, message);
-			return Empty;
-		}
-	} else if (command_type == "event_command") {
-		if (!EventCommand::GetByName(command)) {
-			Log(LogWarning, "ClusterEvents")
-				<< "Event command '" << command << "' does not exist.";
-			return Empty;
-		}
-	} else
-		return Empty;
-
-	attrs->Set(command_type, params->Get("command"));
-	attrs->Set("command_endpoint", sourceEndpoint->GetName());
-
-	Deserialize(host, attrs, false, FAConfig);
-
-	host->SetExtension("agent_check", true);
-
-	Dictionary::Ptr macros = params->Get("macros");
-
-	if (command_type == "check_command") {
-		try {
-			host->ExecuteRemoteCheck(macros);
-		} catch (const std::exception& ex) {
-			CheckResult::Ptr cr = new CheckResult();
-			cr->SetState(ServiceUnknown);
-
-			String output = "Exception occured while checking '" + host->GetName() + "': " + DiagnosticInformation(ex);
-			cr->SetOutput(output);
-
-			double now = Utility::GetTime();
-			cr->SetScheduleStart(now);
-			cr->SetScheduleEnd(now);
-			cr->SetExecutionStart(now);
-			cr->SetExecutionEnd(now);
-
-			Dictionary::Ptr message = MakeCheckResultMessage(host, cr);
-			listener->SyncSendMessage(sourceEndpoint, message);
-
-			Log(LogCritical, "checker", output);
-		}
-	} else if (command_type == "event_command") {
-		host->ExecuteEventHandler(macros, true);
-	}
+	EnqueueCheck(origin, params);
 
 	return Empty;
 }

lib/icinga/clusterevents.hpp

@@ -74,6 +74,21 @@ public:
 	static void NotificationSentToAllUsersHandler(const Notification::Ptr& notification, const Checkable::Ptr& checkable, const std::set<User::Ptr>& users,
 		NotificationType notificationType, const CheckResult::Ptr& cr, const String& author, const String& commentText, const MessageOrigin::Ptr& origin);
 	static Value NotificationSentToAllUsersAPIHandler(const MessageOrigin::Ptr& origin, const Dictionary::Ptr& params);
+
+	static int GetCheckRequestQueueSize();
+	static void LogRemoteCheckQueueInformation();
+
+private:
+	static boost::mutex m_Mutex;
+	static std::deque<std::function<void ()>> m_CheckRequestQueue;
+	static bool m_CheckSchedulerRunning;
+	static int m_ChecksExecutedDuringInterval;
+	static int m_ChecksDroppedDuringInterval;
+	static Timer::Ptr m_LogTimer;
+
+	static void RemoteCheckThreadProc();
+	static void EnqueueCheck(const MessageOrigin::Ptr& origin, const Dictionary::Ptr& params);
+	static void ExecuteCheckFromQueue(const MessageOrigin::Ptr& origin, const Dictionary::Ptr& params);
 };
 
 }

lib/methods/icingachecktask.cpp

@@ -23,6 +23,7 @@
 #include "icinga/checkcommand.hpp"
 #include "icinga/macroprocessor.hpp"
 #include "icinga/icingaapplication.hpp"
+#include "icinga/clusterevents.hpp"
 #include "base/application.hpp"
 #include "base/objectlock.hpp"
 #include "base/utility.hpp"
@@ -84,6 +85,8 @@ void IcingaCheckTask::ScriptFunc(const Checkable::Ptr& checkable, const CheckRes
 	perfdata->Add(new PerfdataValue("active_service_checks_15min", CIB::GetActiveServiceChecksStatistics(60 * 15)));
 	perfdata->Add(new PerfdataValue("passive_service_checks_15min", CIB::GetPassiveServiceChecksStatistics(60 * 15)));
 
+	perfdata->Add(new PerfdataValue("remote_check_queue", ClusterEvents::GetCheckRequestQueueSize()));
+
 	CheckableCheckStatistics scs = CIB::CalculateServiceCheckStats();
 
 	perfdata->Add(new PerfdataValue("min_latency", scs.min_latency));