Give PerfdataWriter a 👷‍♂️WorkQueue like e.g GraphiteWriter🖋️

[Al2Klimov]

Describe the bug

On every Checkable::OnNewCheckResult, PerfdataWriter::CheckResultHandler locks m_StreamMutex and writes to HDD. This blocks Checkable::OnNewCheckResult callers, e.g Checkable::ProcessCheckResult().

To Reproduce

icinga2/lib/perfdata/perfdatawriter.cpp

Lines 56 to 58 in e50eb52

	m_HandleCheckResults = Checkable::OnNewCheckResult.connect([this](const Checkable::Ptr& checkable,
	const CheckResult::Ptr& cr, const MessageOrigin::Ptr&) {
	CheckResultHandler(checkable, cr);

icinga2/lib/perfdata/perfdatawriter.cpp

Lines 97 to 129 in e50eb52

	void PerfdataWriter::CheckResultHandler(const Checkable::Ptr& checkable, const CheckResult::Ptr& cr)
	{
	if (IsPaused())
	return;
	CONTEXT("Writing performance data for object '" << checkable->GetName() << "'");
	if (!IcingaApplication::GetInstance()->GetEnablePerfdata() || !checkable->GetEnablePerfdata())
	return;
	Service::Ptr service = dynamic_pointer_cast<Service>(checkable);
	Host::Ptr host;
	if (service)
	host = service->GetHost();
	else
	host = static_pointer_cast<Host>(checkable);
	MacroProcessor::ResolverList resolvers;
	if (service)
	resolvers.emplace_back("service", service);
	resolvers.emplace_back("host", host);
	if (service) {
	String line = MacroProcessor::ResolveMacros(GetServiceFormatTemplate(), resolvers, cr, nullptr, &PerfdataWriter::EscapeMacroMetric);
	{
	std::unique_lock<std::mutex> lock(m_StreamMutex);
	if (!m_ServiceOutputFile.good())
	return;
	m_ServiceOutputFile << line << "\n";

Expected behavior

The actual work is put in a WorkQueue, exactly like GraphiteWriter does. Then Checkable::OnNewCheckResult() can return early.

Your Environment

Include as many relevant details about the environment you experienced the problem in

• Version used (icinga2 --version): e50eb52

Additional context

ref/NC/820479