Add stats for control messages rate limited

Summary: We're adding a counter that's bumped when we drop a control message (pings, settings, priorities, resets)

Reviewed By: afrind, lnicco

Differential Revision: D49616270

fbshipit-source-id: ad8a2b6162c5fbcf9935f01510d6438d569feaf0

proxygen/lib/http/codec/ControlMessageRateLimitFilter.h

@@ -35,10 +35,12 @@ class ControlMessageRateLimitFilter : public PassThroughHTTPCodecFilter {
                                          HTTPSessionStats* httpSessionStats)
       : resetControlMessages_(numControlMsgsInCurrentInterval_,
                               httpSessionStats),
-        timer_(timer) {
+        timer_(timer),
+        httpSessionStats_(httpSessionStats) {
   }
 
   void setSessionStats(HTTPSessionStats* httpSessionStats) {
+    httpSessionStats_ = httpSessionStats;
     resetControlMessages_.httpSessionStats = httpSessionStats;
   }
 
@@ -117,6 +119,9 @@ class ControlMessageRateLimitFilter : public PassThroughHTTPCodecFilter {
     }
 
     if (++numControlMsgsInCurrentInterval_ > maxControlMsgsPerInterval_) {
+      if (httpSessionStats_) {
+        httpSessionStats_->recordControlMsgRateLimited();
+      }
       HTTPException ex(
           HTTPException::Direction::INGRESS_AND_EGRESS,
           folly::to<std::string>(
@@ -199,6 +204,7 @@ class ControlMessageRateLimitFilter : public PassThroughHTTPCodecFilter {
   ResetCounterTimeout resetDirectErrors_{
       numDirectErrorHandlingInCurrentInterval_};
   folly::HHWheelTimer* timer_{nullptr};
+  HTTPSessionStats* httpSessionStats_{nullptr};
 };
 
 } // namespace proxygen

proxygen/lib/http/session/HTTPSessionStats.h

@@ -36,6 +36,8 @@ class HTTPSessionStats : public TTLBAStats {
 
   virtual void recordControlMsgsInInterval(int64_t) noexcept {
   }
+  virtual void recordControlMsgRateLimited() noexcept {
+  }
 };
 
 } // namespace proxygen

proxygen/lib/http/stats/ThreadLocalHTTPSessionStats.cpp

@@ -37,6 +37,8 @@ TLHTTPSessionStats::TLHTTPSessionStats(const std::string& prefix)
       ttbtxTimeout(prefix + "_ttbtx_timeout", facebook::fb303::SUM),
       ttbtxNotFound(prefix + "_ttbtx_not_found", facebook::fb303::SUM),
       ttbtxExceedLimit(prefix + "_ttbtx_exceed_limit", facebook::fb303::SUM),
+      ctrlMsgsRateLimited(prefix + "_ctrl_msgs_rate_limited",
+                          facebook::fb303::SUM),
       txnsPerSession(prefix + "_txn_per_session",
                      1,
                      0,
@@ -166,4 +168,8 @@ void TLHTTPSessionStats::recordControlMsgsInInterval(
   ctrlMsgsInInterval.add(quantity);
 }
 
+void TLHTTPSessionStats::recordControlMsgRateLimited() noexcept {
+  ctrlMsgsRateLimited.add(1);
+}
+
 } // namespace proxygen

proxygen/lib/http/stats/ThreadLocalHTTPSessionStats.h

@@ -43,6 +43,7 @@ class TLHTTPSessionStats : public HTTPSessionStats {
   void recordSessionPeriodicPingProbeTimeout() noexcept override;
 
   void recordControlMsgsInInterval(int64_t quantity) noexcept override;
+  void recordControlMsgRateLimited() noexcept override;
 
   BaseStats::TLCounter txnsOpen;
   BaseStats::TLCounter pendingBufferedReadBytes;
@@ -66,6 +67,7 @@ class TLHTTPSessionStats : public HTTPSessionStats {
   BaseStats::TLTimeseries ttbtxTimeout;
   BaseStats::TLTimeseries ttbtxNotFound;
   BaseStats::TLTimeseries ttbtxExceedLimit;
+  BaseStats::TLTimeseries ctrlMsgsRateLimited;
   BaseStats::TLHistogram txnsPerSession;
   BaseStats::TLHistogram sessionIdleTime;
   BaseStats::TLHistogram ctrlMsgsInInterval;