Restore "netty:Auto adjust BDP ping frequency" with fix (#9847)

* Revert "Revert "netty:Auto adjust BDP ping frequency (#9650)" (#9821)"

This reverts commit a2bbe84.

* Eliminate half RTT delay in sending BDP Pings when starting up.
* Eliminate delay for bdp ping when current read would push us over the threshold.

netty/src/main/java/io/grpc/netty/AbstractNettyHandler.java

@@ -16,10 +16,12 @@
 
 package io.grpc.netty;
 
+import static com.google.common.base.Preconditions.checkNotNull;
 import static io.netty.handler.codec.http2.Http2CodecUtil.getEmbeddedHttp2Exception;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Ticker;
 import io.grpc.ChannelLogger;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
@@ -44,6 +46,7 @@ abstract class AbstractNettyHandler extends GrpcHttp2ConnectionHandler {
  private boolean autoTuneFlowControlOn;
  private ChannelHandlerContext ctx;
  private boolean initialWindowSent = false;
+ private final Ticker ticker;
 
  private static final long BDP_MEASUREMENT_PING = 1234;
 
@@ -54,20 +57,22 @@ abstract class AbstractNettyHandler extends GrpcHttp2ConnectionHandler {
  Http2Settings initialSettings,
  ChannelLogger negotiationLogger,
  boolean autoFlowControl,
- PingLimiter pingLimiter) {
+ PingLimiter pingLimiter,
+ Ticker ticker) {
  super(channelUnused, decoder, encoder, initialSettings, negotiationLogger);
 
  // During a graceful shutdown, wait until all streams are closed.
  gracefulShutdownTimeoutMillis(GRACEFUL_SHUTDOWN_NO_TIMEOUT);
 
  // Extract the connection window from the settings if it was set.
  this.initialConnectionWindow = initialSettings.initialWindowSize() == null ? -1 :
-  initialSettings.initialWindowSize();
+ initialSettings.initialWindowSize();
  this.autoTuneFlowControlOn = autoFlowControl;
  if (pingLimiter == null) {
  pingLimiter = new AllowPingLimiter();
  }
  this.flowControlPing = new FlowControlPinger(pingLimiter);
+ this.ticker = checkNotNull(ticker, "ticker");
  }
 
  @Override
@@ -131,14 +136,17 @@ void setAutoTuneFlowControl(boolean isOn) {
  final class FlowControlPinger {
 
  private static final int MAX_WINDOW_SIZE = 8 * 1024 * 1024;
+ public static final int MAX_BACKOFF = 10;
 
  private final PingLimiter pingLimiter;
  private int pingCount;
  private int pingReturn;
  private boolean pinging;
  private int dataSizeSincePing;
- private float lastBandwidth; // bytes per second
+ private long lastBandwidth; // bytes per nanosecond
  private long lastPingTime;
+ private int lastTargetWindow;
+ private int pingFrequencyMultiplier;
 
  public FlowControlPinger(PingLimiter pingLimiter) {
  Preconditions.checkNotNull(pingLimiter, "pingLimiter");
@@ -157,10 +165,24 @@ public void onDataRead(int dataLength, int paddingLength) {
  if (!autoTuneFlowControlOn) {
  return;
  }
- if (!isPinging() && pingLimiter.isPingAllowed()) {
+
+ // Note that we are double counting around the ping initiation as the current data will be
+ // added at the end of this method, so will be available in the next check. This at worst
+ // causes us to send a ping one data packet earlier, but makes startup faster if there are
+ // small packets before big ones.
+ int dataForCheck = getDataSincePing() + dataLength + paddingLength;
+ // Need to double the data here to account for targetWindow being set to twice the data below
+ if (!isPinging() && pingLimiter.isPingAllowed()
+ && dataForCheck * 2 >= lastTargetWindow * pingFrequencyMultiplier) {
  setPinging(true);
  sendPing(ctx());
  }
+
+ if (lastTargetWindow == 0) {
+ lastTargetWindow =
+ decoder().flowController().initialWindowSize(connection().connectionStream());
+ }
+
  incrementDataSincePing(dataLength + paddingLength);
  }
 
@@ -169,25 +191,32 @@ public void updateWindow() throws Http2Exception {
  return;
  }
  pingReturn++;
- long elapsedTime = (System.nanoTime() - lastPingTime);
+ setPinging(false);
+
+ long elapsedTime = (ticker.read() - lastPingTime);
  if (elapsedTime == 0) {
  elapsedTime = 1;
  }
+
  long bandwidth = (getDataSincePing() * TimeUnit.SECONDS.toNanos(1)) / elapsedTime;
- Http2LocalFlowController fc = decoder().flowController();
  // Calculate new window size by doubling the observed BDP, but cap at max window
  int targetWindow = Math.min(getDataSincePing() * 2, MAX_WINDOW_SIZE);
- setPinging(false);
+ Http2LocalFlowController fc = decoder().flowController();
  int currentWindow = fc.initialWindowSize(connection().connectionStream());
- if (targetWindow > currentWindow && bandwidth > lastBandwidth) {
- lastBandwidth = bandwidth;
- int increase = targetWindow - currentWindow;
- fc.incrementWindowSize(connection().connectionStream(), increase);
- fc.initialWindowSize(targetWindow);
- Http2Settings settings = new Http2Settings();
- settings.initialWindowSize(targetWindow);
- frameWriter().writeSettings(ctx(), settings, ctx().newPromise());
+ if (bandwidth <= lastBandwidth || targetWindow <= currentWindow) {
+ pingFrequencyMultiplier = Math.min(pingFrequencyMultiplier + 1, MAX_BACKOFF);
+ return;
  }
+
+ pingFrequencyMultiplier = 0; // react quickly when size is changing
+ lastBandwidth = bandwidth;
+ lastTargetWindow = targetWindow;
+ int increase = targetWindow - currentWindow;
+ fc.incrementWindowSize(connection().connectionStream(), increase);
+ fc.initialWindowSize(targetWindow);
+ Http2Settings settings = new Http2Settings();
+ settings.initialWindowSize(targetWindow);
+ frameWriter().writeSettings(ctx(), settings, ctx().newPromise());
  }
 
  private boolean isPinging() {
@@ -200,7 +229,7 @@ private void setPinging(boolean pingOut) {
 
  private void sendPing(ChannelHandlerContext ctx) {
  setDataSizeSincePing(0);
- lastPingTime = System.nanoTime();
+ lastPingTime = ticker.read();
  encoder().writePing(ctx, false, BDP_MEASUREMENT_PING, ctx.newPromise());
  pingCount++;
  }
@@ -229,10 +258,12 @@ private void setDataSizeSincePing(int dataSize) {
  dataSizeSincePing = dataSize;
  }
 
+ // Only used in testing
  @VisibleForTesting
  void setDataSizeAndSincePing(int dataSize) {
  setDataSizeSincePing(dataSize);
- lastPingTime = System.nanoTime() - TimeUnit.SECONDS.toNanos(1);
+ pingFrequencyMultiplier = 1;
+ lastPingTime = ticker.read() ;
  }
  }
 

netty/src/main/java/io/grpc/netty/NettyChannelBuilder.java

@@ -23,6 +23,7 @@
 import static io.grpc.internal.GrpcUtil.KEEPALIVE_TIME_NANOS_DISABLED;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Ticker;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.annotations.CheckReturnValue;
 import com.google.errorprone.annotations.InlineMe;
@@ -738,7 +739,7 @@ public void run() {
  maxMessageSize, maxHeaderListSize, keepAliveTimeNanosState.get(), keepAliveTimeoutNanos,
  keepAliveWithoutCalls, options.getAuthority(), options.getUserAgent(),
  tooManyPingsRunnable, transportTracerFactory.create(), options.getEagAttributes(),
- localSocketPicker, channelLogger, useGetForSafeMethods);
+ localSocketPicker, channelLogger, useGetForSafeMethods, Ticker.systemTicker());
  return transport;
  }
 

netty/src/main/java/io/grpc/netty/NettyClientHandler.java

@@ -24,6 +24,7 @@
 import com.google.common.base.Preconditions;
 import com.google.common.base.Stopwatch;
 import com.google.common.base.Supplier;
+import com.google.common.base.Ticker;
 import io.grpc.Attributes;
 import io.grpc.ChannelLogger;
 import io.grpc.InternalChannelz;
@@ -143,7 +144,8 @@ static NettyClientHandler newHandler(
  TransportTracer transportTracer,
  Attributes eagAttributes,
  String authority,
- ChannelLogger negotiationLogger) {
+ ChannelLogger negotiationLogger,
+ Ticker ticker) {
  Preconditions.checkArgument(maxHeaderListSize > 0, "maxHeaderListSize must be positive");
  Http2HeadersDecoder headersDecoder = new GrpcHttp2ClientHeadersDecoder(maxHeaderListSize);
  Http2FrameReader frameReader = new DefaultHttp2FrameReader(headersDecoder);
@@ -169,7 +171,8 @@ static NettyClientHandler newHandler(
  transportTracer,
  eagAttributes,
  authority,
- negotiationLogger);
+ negotiationLogger,
+ ticker);
  }
 
  @VisibleForTesting
@@ -187,7 +190,8 @@ static NettyClientHandler newHandler(
  TransportTracer transportTracer,
  Attributes eagAttributes,
  String authority,
- ChannelLogger negotiationLogger) {
+ ChannelLogger negotiationLogger,
+ Ticker ticker) {
  Preconditions.checkNotNull(connection, "connection");
  Preconditions.checkNotNull(frameReader, "frameReader");
  Preconditions.checkNotNull(lifecycleManager, "lifecycleManager");
@@ -237,7 +241,8 @@ static NettyClientHandler newHandler(
  eagAttributes,
  authority,
  autoFlowControl,
- pingCounter);
+ pingCounter,
+ ticker);
  }
 
  private NettyClientHandler(
@@ -253,9 +258,10 @@ private NettyClientHandler(
  Attributes eagAttributes,
  String authority,
  boolean autoFlowControl,
- PingLimiter pingLimiter) {
+ PingLimiter pingLimiter,
+ Ticker ticker) {
  super(/* channelUnused= */ null, decoder, encoder, settings,
- negotiationLogger, autoFlowControl, pingLimiter);
+ negotiationLogger, autoFlowControl, pingLimiter, ticker);
  this.lifecycleManager = lifecycleManager;
  this.keepAliveManager = keepAliveManager;
  this.stopwatchFactory = stopwatchFactory;

netty/src/main/java/io/grpc/netty/NettyClientTransport.java

@@ -23,6 +23,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Ticker;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.SettableFuture;
 import io.grpc.Attributes;
@@ -102,6 +103,7 @@ class NettyClientTransport implements ConnectionClientTransport {
  private final LocalSocketPicker localSocketPicker;
  private final ChannelLogger channelLogger;
  private final boolean useGetForSafeMethods;
+ private final Ticker ticker;
 
  NettyClientTransport(
  SocketAddress address, ChannelFactory<? extends Channel> channelFactory,
@@ -112,7 +114,8 @@ class NettyClientTransport implements ConnectionClientTransport {
  boolean keepAliveWithoutCalls, String authority, @Nullable String userAgent,
  Runnable tooManyPingsRunnable, TransportTracer transportTracer, Attributes eagAttributes,
  LocalSocketPicker localSocketPicker, ChannelLogger channelLogger,
- boolean useGetForSafeMethods) {
+ boolean useGetForSafeMethods, Ticker ticker) {
+
  this.negotiator = Preconditions.checkNotNull(negotiator, "negotiator");
  this.negotiationScheme = this.negotiator.scheme();
  this.remoteAddress = Preconditions.checkNotNull(address, "address");
@@ -137,6 +140,7 @@ class NettyClientTransport implements ConnectionClientTransport {
  this.logId = InternalLogId.allocate(getClass(), remoteAddress.toString());
  this.channelLogger = Preconditions.checkNotNull(channelLogger, "channelLogger");
  this.useGetForSafeMethods = useGetForSafeMethods;
+ this.ticker = Preconditions.checkNotNull(ticker, "ticker");
  }
 
  @Override
@@ -225,7 +229,8 @@ public Runnable start(Listener transportListener) {
  transportTracer,
  eagAttributes,
  authorityString,
- channelLogger);
+ channelLogger,
+ ticker);
 
  ChannelHandler negotiationHandler = negotiator.newHandler(handler);
 

netty/src/main/java/io/grpc/netty/NettyServerHandler.java

@@ -34,6 +34,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
+import com.google.common.base.Ticker;
 import io.grpc.Attributes;
 import io.grpc.ChannelLogger;
 import io.grpc.ChannelLogger.ChannelLogLevel;
@@ -190,7 +191,8 @@ static NettyServerHandler newHandler(
  maxConnectionAgeGraceInNanos,
  permitKeepAliveWithoutCalls,
  permitKeepAliveTimeInNanos,
- eagAttributes);
+ eagAttributes,
+ Ticker.systemTicker());
  }
 
  static NettyServerHandler newHandler(
@@ -212,7 +214,8 @@ static NettyServerHandler newHandler(
  long maxConnectionAgeGraceInNanos,
  boolean permitKeepAliveWithoutCalls,
  long permitKeepAliveTimeInNanos,
- Attributes eagAttributes) {
+ Attributes eagAttributes,
+ Ticker ticker) {
  Preconditions.checkArgument(maxStreams > 0, "maxStreams must be positive: %s", maxStreams);
  Preconditions.checkArgument(flowControlWindow > 0, "flowControlWindow must be positive: %s",
  flowControlWindow);
@@ -245,6 +248,10 @@ static NettyServerHandler newHandler(
  settings.maxConcurrentStreams(maxStreams);
  settings.maxHeaderListSize(maxHeaderListSize);
 
+ if (ticker == null) {
+ ticker = Ticker.systemTicker();
+ }
+
  return new NettyServerHandler(
  channelUnused,
  connection,
@@ -258,7 +265,7 @@ static NettyServerHandler newHandler(
  maxConnectionAgeInNanos, maxConnectionAgeGraceInNanos,
  keepAliveEnforcer,
  autoFlowControl,
- eagAttributes);
+ eagAttributes, ticker);
  }
 
  private NettyServerHandler(
@@ -278,9 +285,10 @@ private NettyServerHandler(
  long maxConnectionAgeGraceInNanos,
  final KeepAliveEnforcer keepAliveEnforcer,
  boolean autoFlowControl,
- Attributes eagAttributes) {
+ Attributes eagAttributes,
+ Ticker ticker) {
  super(channelUnused, decoder, encoder, settings, new ServerChannelLogger(),
- autoFlowControl, null);
+ autoFlowControl, null, ticker);
 
  final MaxConnectionIdleManager maxConnectionIdleManager;
  if (maxConnectionIdleInNanos == MAX_CONNECTION_IDLE_NANOS_DISABLED) {
@@ -325,7 +333,6 @@ public void onStreamClosed(Http2Stream stream) {
  this.transportListener = checkNotNull(transportListener, "transportListener");
  this.streamTracerFactories = checkNotNull(streamTracerFactories, "streamTracerFactories");
  this.transportTracer = checkNotNull(transportTracer, "transportTracer");
-
  // Set the frame listener on the decoder.
  decoder().frameListener(new FrameListener());
  }