adding more stats (#429)

- Feature: Add detailed stats on requests and data sizes on a per-bucket level, use parameter `cachestorestats=true` on the `/stats/z$` endpoint to enable
- Feature: Add detailed stats on requests and data sizes on cidstore, use parameter `cidstorestats=true` on the `/stats/z$` endpoint to enable
- Feature: Dashboard now accepts parameters in the URL which is passed on to the `/stats/z$` endpoint

2 files changed, 133 insertions, 3 deletions

diff --git a/src/zencore/include/zencore/stats.h b/src/zencore/include/zencore/stats.h
index 1a0817b99..e8e08f96a 100644
--- a/src/zencore/include/zencore/stats.h
+++ b/src/zencore/include/zencore/stats.h
@@ -222,6 +222,39 @@ private:
 	Histogram m_Histogram;
 };
 
+struct MeterSnapshot
+{
+	uint64_t Count;
+	double	 MeanRate;
+	double	 Rate1;
+	double	 Rate5;
+	double	 Rate15;
+};
+
+struct HistogramSnapshot
+{
+	double Count;
+	double Avg;
+	double Min;
+	double Max;
+	double P75;
+	double P95;
+	double P99;
+	double P999;
+};
+
+struct StatsSnapshot
+{
+	MeterSnapshot	  Meter;
+	HistogramSnapshot Histogram;
+};
+
+struct RequestStatsSnapshot
+{
+	StatsSnapshot Requests;
+	StatsSnapshot Bytes;
+};
+
 /** Metrics for network requests
 
 	Aggregates tracking of duration, payload sizes into a single
@@ -261,19 +294,39 @@ public:
 
 	struct Scope
 	{
-		Scope(OperationTiming& Outer);
+		Scope(RequestStats& Outer, int64_t Bytes);
 		~Scope();
 
+		void SetBytes(int64_t Bytes) { m_Bytes = Bytes; }
+		void Stop();
 		void Cancel();
 
 	private:
-		OperationTiming& m_Outer;
-		uint64_t		 m_StartTick;
+		RequestStats& m_Outer;
+		uint64_t	  m_StartTick;
+		int64_t		  m_Bytes;
 	};
 
 	void EmitSnapshot(std::string_view Tag, CbObjectWriter& Cbo);
 
+	RequestStatsSnapshot Snapshot();
+
 private:
+	static StatsSnapshot GetSnapshot(Meter& M, Histogram& H, double ConversionFactor)
+	{
+		SampleSnapshot Snap = H.Snapshot();
+		return StatsSnapshot{
+			.Meter	   = {.Count = M.Count(), .MeanRate = M.MeanRate(), .Rate1 = M.Rate1(), .Rate5 = M.Rate5(), .Rate15 = M.Rate15()},
+			.Histogram = {.Count = H.Count() * ConversionFactor,
+						  .Avg	 = H.Mean() * ConversionFactor,
+						  .Min	 = H.Min() * ConversionFactor,
+						  .Max	 = H.Max() * ConversionFactor,
+						  .P75	 = Snap.Get75Percentile() * ConversionFactor,
+						  .P95	 = Snap.Get95Percentile() * ConversionFactor,
+						  .P99	 = Snap.Get99Percentile() * ConversionFactor,
+						  .P999	 = Snap.Get999Percentile() * ConversionFactor}};
+	}
+
 	Meter	  m_RequestMeter;
 	Meter	  m_BytesMeter;
 	Histogram m_RequestTimeHistogram;
@@ -286,6 +339,11 @@ void EmitSnapshot(std::string_view Tag, Meter& Stat, CbObjectWriter& Cbo);
 
 void EmitSnapshot(const Histogram& Stat, CbObjectWriter& Cbo, double ConversionFactor);
 
+void EmitSnapshot(std::string_view Tag, const MeterSnapshot& Snapshot, CbObjectWriter& Cbo);
+void EmitSnapshot(std::string_view Tag, const HistogramSnapshot& Snapshot, CbObjectWriter& Cbo);
+void EmitSnapshot(std::string_view Tag, const StatsSnapshot& Snapshot, CbObjectWriter& Cbo);
+void EmitSnapshot(std::string_view Tag, const RequestStatsSnapshot& Snapshot, CbObjectWriter& Cbo);
+
 }  // namespace zen::metrics
 
 namespace zen {
diff --git a/src/zencore/stats.cpp b/src/zencore/stats.cpp
index 372bc42f8..087319fa4 100644
--- a/src/zencore/stats.cpp
+++ b/src/zencore/stats.cpp
@@ -461,6 +461,31 @@ RequestStats::Count() const
 	return m_RequestMeter.Count();
 }
 
+RequestStats::Scope::Scope(RequestStats& Outer, int64_t Bytes) : m_Outer(Outer), m_StartTick(GetHifreqTimerValue()), m_Bytes(Bytes)
+{
+}
+
+RequestStats::Scope::~Scope()
+{
+	Stop();
+}
+
+void
+RequestStats::Scope::Stop()
+{
+	if (m_StartTick != 0)
+	{
+		m_Outer.Update(GetHifreqTimerValue() - m_StartTick, m_Bytes);
+		m_StartTick = 0;
+	}
+}
+
+void
+RequestStats::Scope::Cancel()
+{
+	m_StartTick = 0;
+}
+
 //////////////////////////////////////////////////////////////////////////
 
 void
@@ -489,6 +514,15 @@ RequestStats::EmitSnapshot(std::string_view Tag, CbObjectWriter& Cbo)
 	Cbo.EndObject();
 }
 
+RequestStatsSnapshot
+RequestStats::Snapshot()
+{
+	const double ToSeconds = GetHifreqTimerToSeconds();
+
+	return RequestStatsSnapshot{.Requests = GetSnapshot(m_RequestMeter, m_RequestTimeHistogram, ToSeconds),
+								.Bytes	  = GetSnapshot(m_BytesMeter, m_BytesHistogram, 1.0)};
+}
+
 void
 EmitSnapshot(std::string_view Tag, OperationTiming& Stat, CbObjectWriter& Cbo)
 {
@@ -540,6 +574,44 @@ EmitSnapshot(std::string_view Tag, Meter& Stat, CbObjectWriter& Cbo)
 	Cbo.EndObject();
 }
 
+void
+EmitSnapshot(const MeterSnapshot& Snapshot, CbObjectWriter& Cbo)
+{
+	Cbo << "count" << Snapshot.Count;
+	Cbo << "rate_mean" << Snapshot.MeanRate;
+	Cbo << "rate_1" << Snapshot.Rate1 << "rate_5" << Snapshot.Rate5 << "rate_15" << Snapshot.Rate15;
+}
+
+void
+EmitSnapshot(const HistogramSnapshot& Snapshot, CbObjectWriter& Cbo)
+{
+	Cbo << "t_count" << Snapshot.Count << "t_avg" << Snapshot.Avg;
+	Cbo << "t_min" << Snapshot.Min << "t_max" << Snapshot.Max;
+	Cbo << "t_p75" << Snapshot.P75 << "t_p95" << Snapshot.P95 << "t_p99" << Snapshot.P999;
+}
+
+void
+EmitSnapshot(std::string_view Tag, const StatsSnapshot& Snapshot, CbObjectWriter& Cbo)
+{
+	Cbo.BeginObject(Tag);
+	EmitSnapshot(Snapshot.Meter, Cbo);
+	EmitSnapshot(Snapshot.Histogram, Cbo);
+	Cbo.EndObject();
+}
+
+void
+EmitSnapshot(std::string_view Tag, const RequestStatsSnapshot& Snapshot, CbObjectWriter& Cbo)
+{
+	if (Snapshot.Requests.Meter.Count == 0)
+	{
+		return;
+	}
+	Cbo.BeginObject(Tag);
+	EmitSnapshot("request", Snapshot.Requests, Cbo);
+	EmitSnapshot("bytes", Snapshot.Bytes, Cbo);
+	Cbo.EndObject();
+}
+
 //////////////////////////////////////////////////////////////////////////
 
 #if ZEN_WITH_TESTS