diff --git a/components/checker/checkercomponent.cpp b/components/checker/checkercomponent.cpp
index e72566ace..f260e94a0 100644
--- a/components/checker/checkercomponent.cpp
+++ b/components/checker/checkercomponent.cpp
@@ -60,6 +60,7 @@ void CheckerComponent::Stop(void)
 void CheckerComponent::CheckThreadProc(void)
 {
 	for (;;) {
+		vector<Service::Ptr> services;
 		Service::Ptr service;
 
 		{
@@ -142,6 +143,11 @@ void CheckerComponent::CheckThreadProc(void)
 			m_PendingServices.insert(service);
 		}
 
+		double rwait = service->GetNextCheck() - Utility::GetTime();
+
+		if (abs(rwait - wait) > 5)
+			Logger::Write(LogWarning, "checker", "Check delayed: " + Convert::ToString(-rwait) + ",planned wait: " + Convert::ToString(-wait));
+
 		try {
 			service->BeginExecuteCheck(boost::bind(&CheckerComponent::CheckCompletedHandler, this, service));
 		} catch (const exception& ex) {
diff --git a/components/compat/compatcomponent.cpp b/components/compat/compatcomponent.cpp
index 583f11b94..0c62a69bc 100644
--- a/components/compat/compatcomponent.cpp
+++ b/components/compat/compatcomponent.cpp
@@ -91,7 +91,7 @@ String CompatComponent::GetCommandPath(void) const
 void CompatComponent::Start(void)
 {
 	m_StatusTimer = boost::make_shared<Timer>();
-	m_StatusTimer->SetInterval(5);
+	m_StatusTimer->SetInterval(30);
 	m_StatusTimer->OnTimerExpired.connect(boost::bind(&CompatComponent::StatusTimerHandler, this));
 	m_StatusTimer->Start();
 	m_StatusTimer->Reschedule(0);
@@ -544,22 +544,19 @@ void CompatComponent::StatusTimerHandler(void)
 	}
 
 	BOOST_FOREACH(const DynamicObject::Ptr& object, DynamicType::GetObjects("HostGroup")) {
-		set<Host::Ptr> members;
+		HostGroup::Ptr hg = static_pointer_cast<HostGroup>(object);
 
 		{
-			HostGroup::Ptr hg = static_pointer_cast<HostGroup>(object);
 			ObjectLock olock(hg);
 
 			objectfp << "define hostgroup {" << "\n"
 				 << "\t" << "hostgroup_name" << "\t" << hg->GetName() << "\n"
 				 << "\t" << "notes_url" << "\t" << hg->GetNotesUrl() << "\n"
 				 << "\t" << "action_url" << "\t" << hg->GetActionUrl() << "\n";
-
-			members = hg->GetMembers();
 		}
 
 		objectfp << "\t" << "members" << "\t";
-		DumpNameList(objectfp, members);
+		DumpNameList(objectfp, HostGroup::GetMembers(hg));
 		objectfp << "\n"
 			 << "}" << "\n";
 	}
@@ -572,24 +569,21 @@ void CompatComponent::StatusTimerHandler(void)
 	}
 
 	BOOST_FOREACH(const DynamicObject::Ptr& object, DynamicType::GetObjects("ServiceGroup")) {
-		set<Service::Ptr> members;
+		ServiceGroup::Ptr sg = static_pointer_cast<ServiceGroup>(object);
 
 		{
-			ServiceGroup::Ptr sg = static_pointer_cast<ServiceGroup>(object);
 			ObjectLock olock(sg);
 
 			objectfp << "define servicegroup {" << "\n"
 				 << "\t" << "servicegroup_name" << "\t" << sg->GetName() << "\n"
 				 << "\t" << "notes_url" << "\t" << sg->GetNotesUrl() << "\n"
 				 << "\t" << "action_url" << "\t" << sg->GetActionUrl() << "\n";
-
-			members = sg->GetMembers();
 		}
 
 		objectfp << "\t" << "members" << "\t";
 
 		vector<String> sglist;
-		BOOST_FOREACH(const Service::Ptr& service, members) {
+		BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 			Host::Ptr host;
 			String host_name, short_name;
 
diff --git a/components/compatido/compatidocomponent.cpp b/components/compatido/compatidocomponent.cpp
index 982065ffe..33c3dd5c7 100644
--- a/components/compatido/compatidocomponent.cpp
+++ b/components/compatido/compatidocomponent.cpp
@@ -759,7 +759,7 @@ void CompatIdoComponent::DumpConfigObjects(void)
 
 		vector<String> hglist;
 
-		BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+		BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 			hglist.push_back(host->GetName());
 		}
 
@@ -793,7 +793,7 @@ void CompatIdoComponent::DumpConfigObjects(void)
 		vector<String> sglist;
 		vector<Service::Ptr>::iterator vt;
 
-		BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+		BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 			sglist.push_back(service->GetHost()->GetName());
 			sglist.push_back(service->GetShortName());
 		}
diff --git a/lib/base/dynamicobject.cpp b/lib/base/dynamicobject.cpp
index 81dc93bee..0a73afa93 100644
--- a/lib/base/dynamicobject.cpp
+++ b/lib/base/dynamicobject.cpp
@@ -33,7 +33,7 @@ signals2::signal<void (double, const set<DynamicObject::WeakPtr>&)> DynamicObjec
 signals2::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnFlushObject;
 
 DynamicObject::DynamicObject(const Dictionary::Ptr& serializedObject)
-	: m_Events(false), m_ConfigTx(0)
+	: m_EventSafe(false), m_ConfigTx(0)
 {
 	RegisterAttribute("__name", Attribute_Config);
 	RegisterAttribute("__type", Attribute_Config);
@@ -88,7 +88,7 @@ void DynamicObject::SendLocalUpdateEvents(void)
 	}
 
 	/* Check if it's safe to send events. */
-	if (GetEvents()) {
+	if (GetEventSafe()) {
 		map<String, Value, string_iless>::iterator it;
 		for (it = attrs.begin(); it != attrs.end(); it++)
 			OnAttributeChanged(it->first, it->second);
@@ -237,19 +237,14 @@ void DynamicObject::InternalSetAttribute(const String& name, const Value& data,
 	if (tt.first->second.Type & Attribute_Config)
 		m_ConfigTx = tx;
 
-	DynamicObject::Ptr self;
-	try {
-		self = GetSelf();
-	} catch (const boost::bad_weak_ptr& ex) {
-		/* We're being called from the constructor. Ignore
-		 * the exception. The OnInitCompleted() function
-		 * will take care of adding this object to the list
-		 * of modified objects. */
-	}
+	if (GetEventSafe()) {
+		/* We can't call GetSelf() in the constructor or destructor.
+		 * The OnConstructionCompleted() function will take care of adding this
+		 * object to the list of modified objects later on if we can't
+		 * do it here. */
 
-	if (self) {
 		boost::mutex::scoped_lock lock(m_TransactionMutex);
-		m_ModifiedObjects.insert(self);
+		m_ModifiedObjects.insert(GetSelf());
 	}
 
 	/* Use insert() rather than [] so we don't overwrite
@@ -570,8 +565,11 @@ void DynamicObject::NewTx(void)
 	OnTransactionClosing(tx, objects);
 }
 
-void DynamicObject::OnInitCompleted(void)
+void DynamicObject::OnConstructionCompleted(void)
 {
+	/* It's now safe to send us attribute events. */
+	SetEventSafe(true);
+
 	/* Add this new object to the list of modified objects.
 	 * We're doing this here because we can't construct
 	 * a while WeakPtr from within the object's constructor. */
@@ -579,6 +577,9 @@ void DynamicObject::OnInitCompleted(void)
 	m_ModifiedObjects.insert(GetSelf());
 }
 
+void DynamicObject::OnRegistrationCompleted(void)
+{ }
+
 void DynamicObject::OnAttributeChanged(const String&, const Value&)
 { }
 
@@ -600,12 +601,12 @@ const DynamicObject::AttributeMap& DynamicObject::GetAttributes(void) const
 	return m_Attributes;
 }
 
-void DynamicObject::SetEvents(bool events)
+void DynamicObject::SetEventSafe(bool safe)
 {
-	m_Events = events;
+	m_EventSafe = safe;
 }
 
-bool DynamicObject::GetEvents(void) const
+bool DynamicObject::GetEventSafe(void) const
 {
-	return m_Events;
+	return m_EventSafe;
 }
diff --git a/lib/base/dynamicobject.h b/lib/base/dynamicobject.h
index ea18ff98e..9a84949ba 100644
--- a/lib/base/dynamicobject.h
+++ b/lib/base/dynamicobject.h
@@ -125,8 +125,8 @@ public:
 
 	const AttributeMap& GetAttributes(void) const;
 
-	void SetEvents(bool events);
-	bool GetEvents(void) const;
+	void SetEventSafe(bool initialized);
+	bool GetEventSafe(void) const;
 
 	static DynamicObject::Ptr GetObject(const String& type, const String& name);
 
@@ -137,7 +137,8 @@ public:
 	static double GetCurrentTx(void);
 
 protected:
-	virtual void OnInitCompleted(void);
+	virtual void OnConstructionCompleted(void);
+	virtual void OnRegistrationCompleted(void);
 	virtual void OnAttributeChanged(const String& name, const Value& oldValue);
 
 private:
@@ -149,7 +150,7 @@ private:
 	map<String, Value, string_iless> m_ModifiedAttributes;
 	double m_ConfigTx;
 
-	bool m_Events;
+	bool m_EventSafe;
 
 	static double m_CurrentTx;
 
diff --git a/lib/base/dynamictype.cpp b/lib/base/dynamictype.cpp
index df76b4a87..f7ebce4e0 100644
--- a/lib/base/dynamictype.cpp
+++ b/lib/base/dynamictype.cpp
@@ -80,29 +80,33 @@ String DynamicType::GetName(void) const
 
 void DynamicType::RegisterObject(const DynamicObject::Ptr& object)
 {
-	ObjectLock olock(object);
-	object->SetEvents(true);
+	String name;
 
-	ObjectMap::iterator it = m_ObjectMap.find(object->GetName());
+	{
+		ObjectLock olock(object);
+		name = object->GetName();
+	}
+
+	ObjectMap::iterator it = m_ObjectMap.find(name);
 
 	if (it != m_ObjectMap.end()) {
 		if (it->second == object)
 			return;
 
-		BOOST_THROW_EXCEPTION(runtime_error("RegisterObject() found existing object with the same name: " + object->GetName()));
+		BOOST_THROW_EXCEPTION(runtime_error("RegisterObject() found existing object with the same name: " + name));
 	}
 
-	m_ObjectMap[object->GetName()] = object;
+	m_ObjectMap[name] = object;
 	m_ObjectSet.insert(object);
 
-	/* notify the object that it's been fully initialized */
-	object->OnInitCompleted();
+	/* notify the object that it's been registered */
+	object->OnRegistrationCompleted();
 }
 
 void DynamicType::UnregisterObject(const DynamicObject::Ptr& object)
 {
 	ObjectLock olock(object);
-	object->SetEvents(false);
+	object->SetEventSafe(false);
 
 	m_ObjectMap.erase(object->GetName());
 	m_ObjectSet.erase(object);
@@ -138,16 +142,21 @@ void DynamicType::RegisterType(const DynamicType::Ptr& type)
 DynamicObject::Ptr DynamicType::CreateObject(const Dictionary::Ptr& serializedUpdate) const
 {
 	DynamicObject::Ptr object = m_ObjectFactory(serializedUpdate);
-	ObjectLock olock(object);
 
-	/* register attributes */
-	String name;
-	DynamicAttributeType type;
-	BOOST_FOREACH(tuples::tie(name, type), m_Attributes)
-		object->RegisterAttribute(name, type);
+	{
+		ObjectLock olock(object);
 
-	/* apply the object's non-config attributes */
-	object->ApplyUpdate(serializedUpdate, Attribute_All & ~Attribute_Config);
+		/* register attributes */
+		String name;
+		DynamicAttributeType type;
+		BOOST_FOREACH(tuples::tie(name, type), m_Attributes)
+			object->RegisterAttribute(name, type);
+
+		/* apply the object's non-config attributes */
+		object->ApplyUpdate(serializedUpdate, Attribute_All & ~Attribute_Config);
+	}
+
+	object->OnConstructionCompleted();
 
 	return object;
 }
diff --git a/lib/base/eventqueue.cpp b/lib/base/eventqueue.cpp
index 6eb47bab5..55d8f7fce 100644
--- a/lib/base/eventqueue.cpp
+++ b/lib/base/eventqueue.cpp
@@ -25,15 +25,13 @@ using namespace icinga;
  * @threadsafety Always.
  */
 EventQueue::EventQueue(void)
-	: m_Stopped(false)
+	: m_Stopped(false), m_LastReport(0)
 {
 	int thread_count = thread::hardware_concurrency();
 
 	if (thread_count < 4)
 		thread_count = 4;
 
-	thread_count *= 4;
-
 	for (int i = 0; i < thread_count; i++)
 		m_Threads.create_thread(boost::bind(&EventQueue::QueueThreadProc, this));
 }
@@ -116,4 +114,11 @@ void EventQueue::Post(const EventQueue::Callback& callback)
 	boost::mutex::scoped_lock lock(m_Mutex);
 	m_Events.push_back(callback);
 	m_CV.notify_one();
+
+	int pending = m_Events.size();
+	double now = Utility::GetTime();
+	if (pending > 1000 && now - m_LastReport > 5) {
+		Logger::Write(LogWarning, "base", "More than 1000 pending events: " + Convert::ToString(pending));
+		m_LastReport = now;
+	}
 }
diff --git a/lib/base/eventqueue.h b/lib/base/eventqueue.h
index 36b0ff11a..c92e3934f 100644
--- a/lib/base/eventqueue.h
+++ b/lib/base/eventqueue.h
@@ -47,6 +47,7 @@ private:
 	boost::mutex m_Mutex;
 	condition_variable m_CV;
 
+	double m_LastReport;
 	bool m_Stopped;
 	vector<Callback> m_Events;
 
diff --git a/lib/base/process.cpp b/lib/base/process.cpp
index 58e8b2736..640d89d79 100644
--- a/lib/base/process.cpp
+++ b/lib/base/process.cpp
@@ -24,6 +24,7 @@ using namespace icinga;
 boost::once_flag Process::m_ThreadOnce;
 boost::mutex Process::m_Mutex;
 deque<Process::Ptr> Process::m_Tasks;
+double Process::m_LastReport = 0;
 
 Process::Process(const vector<String>& arguments, const Dictionary::Ptr& extraEnvironment)
 	: AsyncTask<Process, ProcessResult>(), m_Arguments(arguments), m_ExtraEnvironment(extraEnvironment)
@@ -65,9 +66,18 @@ vector<String> Process::SplitCommand(const Value& command)
 
 void Process::Run(void)
 {
+	int count;
+
 	{
 		boost::mutex::scoped_lock lock(m_Mutex);
 		m_Tasks.push_back(GetSelf());
+		count = m_Tasks.size();
+	}
+
+	if (count > 50 && Utility::GetTime() - m_LastReport > 5) {
+		Logger::Write(LogInformation, "base", "More than 50 pending Process tasks: " +
+		    Convert::ToString(count));
+		m_LastReport = Utility::GetTime();
 	}
 
 	NotifyWorker();
diff --git a/lib/base/process.h b/lib/base/process.h
index 618acfaa4..018dc24ee 100644
--- a/lib/base/process.h
+++ b/lib/base/process.h
@@ -48,7 +48,7 @@ public:
 	typedef shared_ptr<Process> Ptr;
 	typedef weak_ptr<Process> WeakPtr;
 
-	static const deque<Process::Ptr>::size_type MaxTasksPerThread = 512;
+	static const deque<Process::Ptr>::size_type MaxTasksPerThread = 128;
 
 	Process(const vector<String>& arguments, const Dictionary::Ptr& extraEnvironment = Dictionary::Ptr());
 
@@ -69,6 +69,7 @@ private:
 	virtual void Run(void);
 
 	static boost::mutex m_Mutex;
+	static double m_LastReport;
 	static deque<Process::Ptr> m_Tasks;
 #ifndef _WIN32
 	static int m_TaskFd;
diff --git a/lib/base/script.cpp b/lib/base/script.cpp
index e83dc9b37..ee7026a51 100644
--- a/lib/base/script.cpp
+++ b/lib/base/script.cpp
@@ -32,9 +32,9 @@ Script::Script(const Dictionary::Ptr& properties)
 	: DynamicObject(properties)
 { }
 
-void Script::OnInitCompleted(void)
+void Script::OnRegistrationCompleted(void)
 {
-	DynamicObject::OnInitCompleted();
+	DynamicObject::OnRegistrationCompleted();
 
 	SpawnInterpreter();
 }
diff --git a/lib/base/script.h b/lib/base/script.h
index daaf288e1..58d5cf97c 100644
--- a/lib/base/script.h
+++ b/lib/base/script.h
@@ -42,7 +42,7 @@ public:
 	String GetCode(void) const;
 
 protected:
-	virtual void OnInitCompleted(void);
+	virtual void OnRegistrationCompleted(void);
 	virtual void OnAttributeUpdate(const String& name, const Value& oldValue);
 
 private:
diff --git a/lib/base/streamlogger.cpp b/lib/base/streamlogger.cpp
index 80ee402df..e45c3809f 100644
--- a/lib/base/streamlogger.cpp
+++ b/lib/base/streamlogger.cpp
@@ -79,7 +79,10 @@ void StreamLogger::ProcessLogEntry(ostream& stream, bool tty, const LogEntry& en
 	char timestamp[100];
 
 	time_t ts = entry.Timestamp;
-	tm tmnow = *localtime(&ts);
+	tm tmnow;
+
+	if (localtime_r(&ts, &tmnow) == NULL)
+		BOOST_THROW_EXCEPTION(PosixException("localtime_r() failed.", errno));
 
 	strftime(timestamp, sizeof(timestamp), "%Y/%m/%d %H:%M:%S %z", &tmnow);
 
@@ -98,7 +101,7 @@ void StreamLogger::ProcessLogEntry(ostream& stream, bool tty, const LogEntry& en
 		}
 	}
 
-	stream << "[" << timestamp << "] "
+	stream << "[" << timestamp << "] <" << boost::this_thread::get_id() << "> "
 		 << Logger::SeverityToString(entry.Severity) << "/" << entry.Facility << ": "
 		 << entry.Message;
 
diff --git a/lib/config/configcompilercontext.cpp b/lib/config/configcompilercontext.cpp
index 44bd2fc02..fc2c1e365 100644
--- a/lib/config/configcompilercontext.cpp
+++ b/lib/config/configcompilercontext.cpp
@@ -137,7 +137,6 @@ void ConfigCompilerContext::ActivateItems(void)
 
 	Logger::Write(LogInformation, "config", "Activating config items in compilation unit '" + m_Unit + "'");
 	BOOST_FOREACH(const ConfigItem::Ptr& item, m_Items) {
-		ObjectLock olock(item);
-		item->Commit();
+		ConfigItem::Commit(item);
 	}
 }
diff --git a/lib/config/configitem.cpp b/lib/config/configitem.cpp
index 8a50fd9be..3b821301a 100644
--- a/lib/config/configitem.cpp
+++ b/lib/config/configitem.cpp
@@ -103,6 +103,11 @@ vector<String> ConfigItem::GetParents(void) const
 	return m_Parents;
 }
 
+set<ConfigItem::WeakPtr> ConfigItem::GetChildren(void) const
+{
+	return m_ChildObjects;
+}
+
 Dictionary::Ptr ConfigItem::Link(void) const
 {
 	Dictionary::Ptr attrs = boost::make_shared<Dictionary>();
@@ -151,42 +156,70 @@ void ConfigItem::InternalLink(const Dictionary::Ptr& dictionary) const
  *
  * @returns The DynamicObject that was created/updated.
  */
-DynamicObject::Ptr ConfigItem::Commit(void)
+DynamicObject::Ptr ConfigItem::Commit(const ConfigItem::Ptr& self)
 {
-	Logger::Write(LogDebug, "base", "Commit called for ConfigItem Type=" + GetType() + ", Name=" + GetName());
+	String type, name;
+	DynamicObject::Ptr dobj;
+	vector<String> parents;
+	Dictionary::Ptr properties;
+
+	{
+		ObjectLock olock(self);
+		type = self->GetType();
+		name = self->GetName();
+		dobj = self->GetDynamicObject();
+		parents = self->GetParents();
+		properties = self->Link();
+	}
+
+	Logger::Write(LogDebug, "base", "Commit called for ConfigItem Type=" + type + ", Name=" + name);
 
 	/* Make sure the type is valid. */
-	DynamicType::Ptr dtype = DynamicType::GetByName(GetType());
+	DynamicType::Ptr dtype = DynamicType::GetByName(type);
 
 	if (!dtype)
-		BOOST_THROW_EXCEPTION(runtime_error("Type '" + GetType() + "' does not exist."));
+		BOOST_THROW_EXCEPTION(runtime_error("Type '" + type + "' does not exist."));
 
-	/* Try to find an existing item with the same type and name. */
-	pair<String, String> ikey = make_pair(GetType(), GetName());
-	ItemMap::iterator it = m_Items.find(ikey);
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
 
-	if (it != m_Items.end()) {
-		/* Unregister the old item from its parents. */
-		ConfigItem::Ptr oldItem = it->second;
-		ObjectLock olock(oldItem);
-		oldItem->UnregisterFromParents();
+		/* Try to find an existing item with the same type and name. */
+		pair<String, String> ikey = make_pair(type, name);
+		ItemMap::iterator it = m_Items.find(ikey);
 
-		/* Steal the old item's children. */
-		m_ChildObjects = oldItem->m_ChildObjects;
+		set<ConfigItem::WeakPtr> children;
+
+		if (it != m_Items.end()) {
+			/* Unregister the old item from its parents. */
+			ConfigItem::Ptr oldItem = it->second;
+			ObjectLock olock(oldItem);
+			oldItem->UnregisterFromParents();
+
+			/* Steal the old item's children. */
+			children = oldItem->GetChildren();
+		}
+
+		{
+			ObjectLock olock(self);
+			self->m_ChildObjects = children;
+		}
+
+		/* Register this item. */
+		m_Items[ikey] = self;
+	}
+
+	if (!dobj) {
+		ObjectLock olock(dtype);
+		dobj = dtype->GetObject(name);
 	}
 
 	/* Register this item with its parents. */
-	BOOST_FOREACH(const String& parentName, m_Parents) {
-		ConfigItem::Ptr parent = GetObject(GetType(), parentName);
+	BOOST_FOREACH(const String& parentName, parents) {
+		ConfigItem::Ptr parent = GetObject(type, parentName);
 		ObjectLock olock(parent);
-		parent->RegisterChild(GetSelf());
+		parent->RegisterChild(self);
 	}
 
-	/* Register this item. */
-	m_Items[ikey] = GetSelf();
-
-	Dictionary::Ptr properties = Link();
-
 	/* Create a fake update in the format that
 	 * DynamicObject::ApplyUpdate expects. */
 	Dictionary::Ptr attrs = boost::make_shared<Dictionary>();
@@ -206,13 +239,6 @@ DynamicObject::Ptr ConfigItem::Commit(void)
 	update->Set("configTx", DynamicObject::GetCurrentTx());
 
 	/* Update or create the object and apply the configuration settings. */
-	DynamicObject::Ptr dobj = m_DynamicObject.lock();
-
-	if (!dobj) {
-		ObjectLock dlock(dtype);
-		dobj = dtype->GetObject(GetName());
-	}
-
 	bool was_null = false;
 
 	if (!dobj) {
@@ -227,7 +253,7 @@ DynamicObject::Ptr ConfigItem::Commit(void)
 		if (!was_null)
 			dobj->ApplyUpdate(update, Attribute_Config);
 
-		m_DynamicObject = dobj;
+		self->m_DynamicObject = dobj;
 
 		if (dobj->IsAbstract())
 			dobj->Unregister();
@@ -237,7 +263,12 @@ DynamicObject::Ptr ConfigItem::Commit(void)
 
 	/* We need to make a copy of the child objects because the
 	 * OnParentCommitted() handler is going to update the list. */
-	set<ConfigItem::WeakPtr> children = m_ChildObjects;
+	set<ConfigItem::WeakPtr> children;
+
+	{
+		ObjectLock olock(self);
+		children = self->m_ChildObjects;
+	}
 
 	/* notify our children of the update */
 	BOOST_FOREACH(const ConfigItem::WeakPtr wchild, children) {
@@ -246,11 +277,10 @@ DynamicObject::Ptr ConfigItem::Commit(void)
 		if (!child)
 			continue;
 
-		ObjectLock olock(child);
 		child->OnParentCommitted();
 	}
 
-	OnCommitted(GetSelf());
+	OnCommitted(self);
 
 	return dobj;
 }
@@ -305,8 +335,17 @@ void ConfigItem::UnregisterFromParents(void)
  */
 void ConfigItem::OnParentCommitted(void)
 {
-	if (GetObject(GetType(), GetName()) == static_cast<ConfigItem::Ptr>(GetSelf()))
-		Commit();
+	ConfigItem::Ptr self;
+
+	{
+		ObjectLock olock(this);
+		self = GetSelf();
+
+		if (GetObject(self->GetType(), self->GetName()) != self)
+			return;
+	}
+
+	Commit(self);
 }
 
 /**
diff --git a/lib/config/configitem.h b/lib/config/configitem.h
index 77912962f..a20b36143 100644
--- a/lib/config/configitem.h
+++ b/lib/config/configitem.h
@@ -43,10 +43,11 @@ public:
 	String GetUnit(void) const;
 
 	vector<String> GetParents(void) const;
+	set<ConfigItem::WeakPtr> GetChildren(void) const;
 
 	ExpressionList::Ptr GetExpressionList(void) const;
 
-	DynamicObject::Ptr Commit(void);
+	static DynamicObject::Ptr Commit(const ConfigItem::Ptr& self);
 	void Unregister(void);
 
 	void Dump(ostream& fp) const;
diff --git a/lib/icinga/externalcommandprocessor.cpp b/lib/icinga/externalcommandprocessor.cpp
index fd22a52f4..fb4290539 100644
--- a/lib/icinga/externalcommandprocessor.cpp
+++ b/lib/icinga/externalcommandprocessor.cpp
@@ -403,7 +403,7 @@ void ExternalCommandProcessor::EnableHostgroupSvcChecks(double, const vector<Str
 
 	HostGroup::Ptr hg = HostGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+	BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 		BOOST_FOREACH(const Service::Ptr& service, host->GetServices()) {
 			Logger::Write(LogInformation, "icinga", "Enabling active checks for service '" + service->GetName() + "'");
 			service->SetEnableActiveChecks(true);
@@ -418,7 +418,7 @@ void ExternalCommandProcessor::DisableHostgroupSvcChecks(double, const vector<St
 
 	HostGroup::Ptr hg = HostGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+	BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 		BOOST_FOREACH(const Service::Ptr& service, host->GetServices()) {
 			Logger::Write(LogInformation, "icinga", "Disabling active checks for service '" + service->GetName() + "'");
 			service->SetEnableActiveChecks(false);
@@ -433,7 +433,7 @@ void ExternalCommandProcessor::EnableServicegroupSvcChecks(double, const vector<
 
 	ServiceGroup::Ptr sg = ServiceGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+	BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 		Logger::Write(LogInformation, "icinga", "Enabling active checks for service '" + service->GetName() + "'");
 		service->SetEnableActiveChecks(true);
 	}
@@ -446,7 +446,7 @@ void ExternalCommandProcessor::DisableServicegroupSvcChecks(double, const vector
 
 	ServiceGroup::Ptr sg = ServiceGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+	BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 		Logger::Write(LogInformation, "icinga", "Disabling active checks for service '" + service->GetName() + "'");
 		service->SetEnableActiveChecks(false);
 	}
@@ -481,7 +481,7 @@ void ExternalCommandProcessor::EnableServicegroupPassiveSvcChecks(double, const
 
 	ServiceGroup::Ptr sg = ServiceGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+	BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 		Logger::Write(LogInformation, "icinga", "Enabling passive checks for service '" + service->GetName() + "'");
 		service->SetEnablePassiveChecks(true);
 	}
@@ -494,7 +494,7 @@ void ExternalCommandProcessor::DisableServicegroupPassiveSvcChecks(double, const
 
 	ServiceGroup::Ptr sg = ServiceGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+	BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 		Logger::Write(LogInformation, "icinga", "Disabling passive checks for service '" + service->GetName() + "'");
 		service->SetEnablePassiveChecks(true);
 	}
@@ -507,7 +507,7 @@ void ExternalCommandProcessor::EnableHostgroupPassiveSvcChecks(double, const vec
 
 	HostGroup::Ptr hg = HostGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+	BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 		BOOST_FOREACH(const Service::Ptr& service, host->GetServices()) {
 			Logger::Write(LogInformation, "icinga", "Enabling passive checks for service '" + service->GetName() + "'");
 			service->SetEnablePassiveChecks(true);
@@ -522,7 +522,7 @@ void ExternalCommandProcessor::DisableHostgroupPassiveSvcChecks(double, const ve
 
 	HostGroup::Ptr hg = HostGroup::GetByName(arguments[0]);
 
-	BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+	BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 		BOOST_FOREACH(const Service::Ptr& service, host->GetServices()) {
 			Logger::Write(LogInformation, "icinga", "Disabling passive checks for service '" + service->GetName() + "'");
 			service->SetEnablePassiveChecks(false);
@@ -657,7 +657,7 @@ void ExternalCommandProcessor::ScheduleHostgroupHostDowntime(double, const vecto
 	if (triggeredByLegacy != 0)
 		triggeredBy = Service::GetDowntimeIDFromLegacyID(triggeredByLegacy);
 
-	BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+	BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 		Logger::Write(LogInformation, "icinga", "Creating downtime for host " + host->GetName());
 		Service::Ptr service = host->GetHostCheckService();
 		if (service) {
@@ -686,7 +686,7 @@ void ExternalCommandProcessor::ScheduleHostgroupSvcDowntime(double, const vector
 
 	set<Service::Ptr> services;
 
-	BOOST_FOREACH(const Host::Ptr& host, hg->GetMembers()) {
+	BOOST_FOREACH(const Host::Ptr& host, HostGroup::GetMembers(hg)) {
 		BOOST_FOREACH(const Service::Ptr& service, host->GetServices()) {
 			services.insert(service);
 		}
@@ -718,7 +718,7 @@ void ExternalCommandProcessor::ScheduleServicegroupHostDowntime(double, const ve
 
 	set<Service::Ptr> services;
 
-	BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+	BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 		Host::Ptr host = service->GetHost();
 		Service::Ptr hcService = host->GetHostCheckService();
 		if (hcService)
@@ -745,7 +745,7 @@ void ExternalCommandProcessor::ScheduleServicegroupSvcDowntime(double, const vec
 	if (triggeredByLegacy != 0)
 		triggeredBy = Service::GetDowntimeIDFromLegacyID(triggeredByLegacy);
 
-	BOOST_FOREACH(const Service::Ptr& service, sg->GetMembers()) {
+	BOOST_FOREACH(const Service::Ptr& service, ServiceGroup::GetMembers(sg)) {
 		Logger::Write(LogInformation, "icinga", "Creating downtime for service " + service->GetName());
 		(void) service->AddDowntime(arguments[6], arguments[7],
 		    Convert::ToDouble(arguments[1]), Convert::ToDouble(arguments[2]),
diff --git a/lib/icinga/host.cpp b/lib/icinga/host.cpp
index 5c5e0bf0d..4bb21902f 100644
--- a/lib/icinga/host.cpp
+++ b/lib/icinga/host.cpp
@@ -34,13 +34,18 @@ REGISTER_TYPE(Host, hostAttributes);
 
 Host::Host(const Dictionary::Ptr& properties)
 	: DynamicObject(properties)
-{
-	HostGroup::InvalidateMembersCache();
-}
+{ }
 
-void Host::OnInitCompleted(void)
+void Host::OnRegistrationCompleted(void)
 {
-	UpdateSlaveServices();
+	DynamicObject::OnRegistrationCompleted();
+
+	HostGroup::InvalidateMembersCache();
+
+	{
+		ObjectLock olock(this);
+		UpdateSlaveServices();
+	}
 }
 
 Host::~Host(void)
@@ -264,7 +269,7 @@ void Host::UpdateSlaveServices(void)
 			}
 
 			ConfigItem::Ptr serviceItem = builder->Compile();
-			serviceItem->Commit();
+			ConfigItem::Commit(serviceItem);
 
 			newServices->Set(name, serviceItem);
 		}
diff --git a/lib/icinga/host.h b/lib/icinga/host.h
index 936da7dac..244232f09 100644
--- a/lib/icinga/host.h
+++ b/lib/icinga/host.h
@@ -67,7 +67,7 @@ public:
 	    const std::vector<icinga::Value>& arguments);
 
 protected:
-	void OnInitCompleted(void);
+	void OnRegistrationCompleted(void);
 	void OnAttributeChanged(const String& name, const Value& oldValue);
 
 private:
diff --git a/lib/icinga/hostgroup.cpp b/lib/icinga/hostgroup.cpp
index a41dfef2d..a8d2b7004 100644
--- a/lib/icinga/hostgroup.cpp
+++ b/lib/icinga/hostgroup.cpp
@@ -72,15 +72,23 @@ HostGroup::Ptr HostGroup::GetByName(const String& name)
 	return dynamic_pointer_cast<HostGroup>(configObject);
 }
 
-set<Host::Ptr> HostGroup::GetMembers(void) const
+set<Host::Ptr> HostGroup::GetMembers(const HostGroup::Ptr& self)
 {
-	set<Host::Ptr> hosts;
+	String name;
 
-	ValidateMembersCache();
+	{
+		ObjectLock olock(self);
+		name = self->GetName();
+	}
+
+	set<Host::Ptr> hosts;
 
 	{
 		boost::mutex::scoped_lock lock(m_Mutex);
-		BOOST_FOREACH(const Host::WeakPtr& hst, m_MembersCache[GetName()]) {
+
+		ValidateMembersCache();
+
+		BOOST_FOREACH(const Host::WeakPtr& hst, m_MembersCache[name]) {
 			Host::Ptr host = hst.lock();
 
 			if (!host)
@@ -100,10 +108,11 @@ void HostGroup::InvalidateMembersCache(void)
 	m_MembersCache.clear();
 }
 
+/**
+ * @threadsafety Caller must hold m_Mutex.
+ */
 void HostGroup::ValidateMembersCache(void)
 {
-	boost::mutex::scoped_lock lock(m_Mutex);
-
 	if (m_MembersCacheValid)
 		return;
 
diff --git a/lib/icinga/hostgroup.h b/lib/icinga/hostgroup.h
index a5d08384d..faa81b73a 100644
--- a/lib/icinga/hostgroup.h
+++ b/lib/icinga/hostgroup.h
@@ -43,7 +43,7 @@ public:
 	String GetNotesUrl(void) const;
 	String GetActionUrl(void) const;
 
-	set<Host::Ptr> GetMembers(void) const;
+	static set<Host::Ptr> GetMembers(const HostGroup::Ptr& self);
 	static void InvalidateMembersCache(void);
 
 private:
diff --git a/lib/icinga/pluginchecktask.cpp b/lib/icinga/pluginchecktask.cpp
index 38aa653e7..c63560efb 100644
--- a/lib/icinga/pluginchecktask.cpp
+++ b/lib/icinga/pluginchecktask.cpp
@@ -77,12 +77,11 @@ void PluginCheckTask::ProcessFinishedHandler(PluginCheckTask ct)
 	ProcessResult pr;
 
 	try {
+		ObjectLock olock(ct.m_Process);
 		pr = ct.m_Process->GetResult();
 	} catch (...) {
-		{
-			ObjectLock olock(ct.m_Task);
-			ct.m_Task->FinishException(boost::current_exception());
-		}
+		ObjectLock olock(ct.m_Task);
+		ct.m_Task->FinishException(boost::current_exception());
 
 		return;
 	}
@@ -94,10 +93,8 @@ void PluginCheckTask::ProcessFinishedHandler(PluginCheckTask ct)
 	result->Set("execution_start", pr.ExecutionStart);
 	result->Set("execution_end", pr.ExecutionEnd);
 
-	{
-		ObjectLock olock(ct.m_Task);
-		ct.m_Task->FinishResult(result);
-	}
+	ObjectLock olock(ct.m_Task);
+	ct.m_Task->FinishResult(result);
 }
 
 ServiceState PluginCheckTask::ExitStatusToState(int exitStatus)
diff --git a/lib/icinga/service-notification.cpp b/lib/icinga/service-notification.cpp
index 21ba7a737..6cc305506 100644
--- a/lib/icinga/service-notification.cpp
+++ b/lib/icinga/service-notification.cpp
@@ -182,7 +182,7 @@ void Service::UpdateSlaveNotifications(void)
 			}
 
 			ConfigItem::Ptr notificationItem = builder->Compile();
-			notificationItem->Commit();
+			ConfigItem::Commit(notificationItem);
 
 			newNotifications->Set(name, notificationItem);
 		}
diff --git a/lib/icinga/service.cpp b/lib/icinga/service.cpp
index e2f1f68a7..355df9899 100644
--- a/lib/icinga/service.cpp
+++ b/lib/icinga/service.cpp
@@ -47,16 +47,21 @@ REGISTER_TYPE(Service, serviceAttributes);
 
 Service::Service(const Dictionary::Ptr& serializedObject)
 	: DynamicObject(serializedObject)
+{ }
+
+void Service::OnRegistrationCompleted(void)
 {
+	DynamicObject::OnRegistrationCompleted();
+
 	ServiceGroup::InvalidateMembersCache();
 	Host::InvalidateServicesCache();
 	Service::InvalidateDowntimesCache();
 	Service::InvalidateCommentsCache();
-}
 
-void Service::OnInitCompleted(void)
-{
-	UpdateSlaveNotifications();
+	{
+		ObjectLock olock(this);
+		UpdateSlaveNotifications();
+	}
 }
 
 Service::~Service(void)
diff --git a/lib/icinga/service.h b/lib/icinga/service.h
index 8a44fc198..22da15818 100644
--- a/lib/icinga/service.h
+++ b/lib/icinga/service.h
@@ -248,7 +248,7 @@ public:
 	void SetNextNotification(double time);
 
 protected:
-	virtual void OnInitCompleted(void);
+	virtual void OnRegistrationCompleted(void);
 	virtual void OnAttributeChanged(const String& name, const Value& oldValue);
 
 private:
diff --git a/lib/icinga/servicegroup.cpp b/lib/icinga/servicegroup.cpp
index fd168886b..049491e17 100644
--- a/lib/icinga/servicegroup.cpp
+++ b/lib/icinga/servicegroup.cpp
@@ -72,15 +72,23 @@ ServiceGroup::Ptr ServiceGroup::GetByName(const String& name)
 	return dynamic_pointer_cast<ServiceGroup>(configObject);
 }
 
-set<Service::Ptr> ServiceGroup::GetMembers(void) const
+set<Service::Ptr> ServiceGroup::GetMembers(const ServiceGroup::Ptr& self)
 {
-	set<Service::Ptr> services;
+	String name;
 
-	ValidateMembersCache();
+	{
+		ObjectLock olock(self);
+		name = self->GetName();
+	}
+
+	set<Service::Ptr> services;
 
 	{
 		boost::mutex::scoped_lock lock(m_Mutex);
-		BOOST_FOREACH(const Service::WeakPtr& svc, m_MembersCache[GetName()]) {
+
+		ValidateMembersCache();
+
+		BOOST_FOREACH(const Service::WeakPtr& svc, m_MembersCache[name]) {
 			Service::Ptr service = svc.lock();
 
 			if (!service)
@@ -100,10 +108,11 @@ void ServiceGroup::InvalidateMembersCache(void)
 	m_MembersCache.clear();
 }
 
+/**
+ * @threadsafety Caller must hold m_Mutex.
+ */
 void ServiceGroup::ValidateMembersCache(void)
 {
-	boost::mutex::scoped_lock lock(m_Mutex);
-
 	if (m_MembersCacheValid)
 		return;
 
diff --git a/lib/icinga/servicegroup.h b/lib/icinga/servicegroup.h
index f9d8b01e5..2230f4663 100644
--- a/lib/icinga/servicegroup.h
+++ b/lib/icinga/servicegroup.h
@@ -43,7 +43,7 @@ public:
 	String GetNotesUrl(void) const;
 	String GetActionUrl(void) const;
 
-	set<Service::Ptr> GetMembers(void) const;
+	static set<Service::Ptr> GetMembers(const ServiceGroup::Ptr& self);
 	static void InvalidateMembersCache(void);
 
 private:
diff --git a/lib/remoting/endpoint.cpp b/lib/remoting/endpoint.cpp
index a323c250e..7da12f97f 100644
--- a/lib/remoting/endpoint.cpp
+++ b/lib/remoting/endpoint.cpp
@@ -87,7 +87,7 @@ Endpoint::Ptr Endpoint::MakeEndpoint(const String& name, bool replicated, bool l
 	endpointConfig->SetLocal(!replicated);
 	endpointConfig->AddExpression("local", OperatorSet, local);
 
-	DynamicObject::Ptr object = endpointConfig->Compile()->Commit();
+	DynamicObject::Ptr object = ConfigItem::Commit(endpointConfig->Compile());
 	return dynamic_pointer_cast<Endpoint>(object);
 }