Net.QuicSession.OutOfOrderLargePacketsReceived

The number of times the current received packet had a lower sequence number
than the previously received packet sequence number, and the size of the
current packet is larger than the size of the previous packet.

Review URL: https://codereview.chromium.org/905593002

Cr-Commit-Position: refs/heads/master@{#315087}

net/quic/quic_connection_logger.cc

@@ -326,9 +326,11 @@ QuicConnectionLogger::QuicConnectionLogger(QuicSession* session,
       session_(session),
       last_received_packet_sequence_number_(0),
       last_received_packet_size_(0),
+      previous_received_packet_size_(0),
       largest_received_packet_sequence_number_(0),
       largest_received_missing_packet_sequence_number_(0),
       num_out_of_order_received_packets_(0),
+      num_out_of_order_large_received_packets_(0),
       num_packets_received_(0),
       num_truncated_acks_sent_(0),
       num_truncated_acks_received_(0),
@@ -345,6 +347,8 @@ QuicConnectionLogger::QuicConnectionLogger(QuicSession* session,
 QuicConnectionLogger::~QuicConnectionLogger() {
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.OutOfOrderPacketsReceived",
                        num_out_of_order_received_packets_);
+  UMA_HISTOGRAM_COUNTS("Net.QuicSession.OutOfOrderLargePacketsReceived",
+                       num_out_of_order_large_received_packets_);
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.TruncatedAcksSent",
                        num_truncated_acks_sent_);
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.TruncatedAcksReceived",
@@ -496,6 +500,7 @@ void QuicConnectionLogger::OnPacketReceived(const IPEndPoint& self_address,
                               ADDRESS_FAMILY_LAST);
   }
 
+  previous_received_packet_size_ = last_received_packet_size_;
   last_received_packet_size_ = packet.length();
   net_log_.AddEvent(
       NetLog::TYPE_QUIC_SESSION_PACKET_RECEIVED,
@@ -546,6 +551,8 @@ void QuicConnectionLogger::OnPacketHeader(const QuicPacketHeader& header) {
   }
   if (header.packet_sequence_number < last_received_packet_sequence_number_) {
     ++num_out_of_order_received_packets_;
+    if (previous_received_packet_size_ < last_received_packet_size_)
+      ++num_out_of_order_large_received_packets_;
     UMA_HISTOGRAM_COUNTS(
         "Net.QuicSession.OutOfOrderGapReceived",
         static_cast<base::HistogramBase::Sample>(

net/quic/quic_connection_logger.h

@@ -118,6 +118,8 @@ class NET_EXPORT_PRIVATE QuicConnectionLogger
   QuicPacketSequenceNumber last_received_packet_sequence_number_;
   // The size of the most recently received packet.
   size_t last_received_packet_size_;
+  // The size of the previously received packet.
+  size_t previous_received_packet_size_;
   // The largest packet sequence number received.  In the case where a packet is
   // received late (out of order), this value will not be updated.
   QuicPacketSequenceNumber largest_received_packet_sequence_number_;
@@ -127,6 +129,11 @@ class NET_EXPORT_PRIVATE QuicConnectionLogger
   // Number of times that the current received packet sequence number is
   // smaller than the last received packet sequence number.
   size_t num_out_of_order_received_packets_;
+  // Number of times that the current received packet sequence number is
+  // smaller than the last received packet sequence number and where the
+  // size of the current packet is larger than the size of the previous
+  // packet.
+  size_t num_out_of_order_large_received_packets_;
   // The number of times that OnPacketHeader was called.
   // If the network replicates packets, then this number may be slightly
   // different from the real number of distinct packets received.

tools/metrics/histograms/histograms.xml

@@ -18527,6 +18527,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Net.QuicSession.OutOfOrderLargePacketsReceived">
+  <owner>rch@chromium.org</owner>
+  <summary>
+    The number of times the current received packet had a lower sequence number
+    than the previously received packet sequence number, and the size of the
+    current packet is larger than the size of the previous packet.
+  </summary>
+</histogram>
+
 <histogram name="Net.QuicSession.OutOfOrderPacketsReceived">
   <owner>rch@chromium.org</owner>
   <summary>