statsd metrics reporting (#496)

added support for reporting metrics via statsd style UDP messaging, which is supported by many monitoring solution providers

this change adds reporting only of three cache related metrics (hit/miss/put) but this should be extended to include more metrics after additional evaluation

2 files changed, 99 insertions, 0 deletions

diff --git a/src/zenserver/stats/statsreporter.cpp b/src/zenserver/stats/statsreporter.cpp
new file mode 100644
index 000000000..5d5ef4bfa
--- /dev/null
+++ b/src/zenserver/stats/statsreporter.cpp
@@ -0,0 +1,60 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "statsreporter.h"
+
+#include <zencore/logging.h>
+#include <zennet/statsdclient.h>
+
+namespace zen {
+
+StatsReporter::StatsReporter()
+{
+}
+
+StatsReporter::~StatsReporter()
+{
+}
+
+void
+StatsReporter::Initialize(const ZenStatsConfig& Config)
+{
+	RwLock::ExclusiveLockScope _(m_Lock);
+
+	if (Config.Enabled)
+	{
+		ZEN_INFO("initializing stats reporter: {}:{}", Config.StatsdHost, Config.StatsdPort)
+		m_Statsd = CreateStatsDaemonClient(Config.StatsdHost, gsl::narrow<uint16_t>(Config.StatsdPort));
+		m_Statsd->SetMessageSize(1500, false);
+	}
+}
+
+void
+StatsReporter::Shutdown()
+{
+	RwLock::ExclusiveLockScope _(m_Lock);
+	m_Statsd.reset();
+}
+
+void
+StatsReporter::AddProvider(StatsProvider* Provider)
+{
+	RwLock::ExclusiveLockScope _(m_Lock);
+	m_Providers.push_back(Provider);
+}
+
+void
+StatsReporter::ReportStats()
+{
+	RwLock::ExclusiveLockScope _(m_Lock);
+	if (m_Statsd)
+	{
+		for (StatsProvider* Provider : m_Providers)
+		{
+			Provider->ReportMetrics(*m_Statsd);
+		}
+
+		m_Statsd->Flush();
+	}
+}
+
+}  // namespace zen
diff --git a/src/zenserver/stats/statsreporter.h b/src/zenserver/stats/statsreporter.h
new file mode 100644
index 000000000..ed6ec6c55
--- /dev/null
+++ b/src/zenserver/stats/statsreporter.h
@@ -0,0 +1,39 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include "config.h"
+
+#include <zencore/thread.h>
+
+namespace zen {
+
+class StatsDaemonClient;
+
+class StatsProvider
+{
+public:
+	virtual void ReportMetrics(StatsDaemonClient& Statsd) = 0;
+};
+
+class StatsReporter
+{
+public:
+	StatsReporter();
+	~StatsReporter();
+
+	StatsReporter& operator=(const StatsReporter&) = delete;
+	StatsReporter(const StatsReporter&)			   = delete;
+
+	void Initialize(const ZenStatsConfig& Config);
+	void Shutdown();
+	void AddProvider(StatsProvider* Provider);
+	void ReportStats();
+
+private:
+	RwLock							   m_Lock;
+	std::unique_ptr<StatsDaemonClient> m_Statsd;
+	std::vector<StatsProvider*>		   m_Providers;
+};
+
+}  // namespace zen