diff --git a/java/google/registry/proxy/handler/BackendMetricsHandler.java b/java/google/registry/proxy/handler/BackendMetricsHandler.java
index 7f0d81844..640118aad 100644
--- a/java/google/registry/proxy/handler/BackendMetricsHandler.java
+++ b/java/google/registry/proxy/handler/BackendMetricsHandler.java
@@ -113,6 +113,10 @@ public class BackendMetricsHandler extends ChannelDuplexHandler {
     }
     FullHttpRequest request = (FullHttpRequest) msg;
 
+    // Record request size now because the content would have read by the time the listener is
+    // called and the readable bytes would be zero by then.
+    int bytes = request.content().readableBytes();
+
     // Record sent time before write finishes allows us to take network latency into account.
     DateTime sentTime = clock.nowUtc();
     ChannelFuture unusedFuture =
@@ -121,7 +125,7 @@ public class BackendMetricsHandler extends ChannelDuplexHandler {
                 future -> {
                   if (future.isSuccess()) {
                     // Only instrument request metrics when the request is actually sent to GAE.
-                    metrics.requestSent(relayedProtocolName, clientCertHash, request);
+                    metrics.requestSent(relayedProtocolName, clientCertHash, bytes);
                     requestSentTimeQueue.add(sentTime);
                   }
                 });
diff --git a/java/google/registry/proxy/metric/BackendMetrics.java b/java/google/registry/proxy/metric/BackendMetrics.java
index c6fa4310d..3682a910e 100644
--- a/java/google/registry/proxy/metric/BackendMetrics.java
+++ b/java/google/registry/proxy/metric/BackendMetrics.java
@@ -23,7 +23,6 @@ import com.google.monitoring.metrics.IncrementableMetric;
 import com.google.monitoring.metrics.LabelDescriptor;
 import com.google.monitoring.metrics.MetricRegistryImpl;
 import google.registry.util.NonFinalForTesting;
-import io.netty.handler.codec.http.FullHttpRequest;
 import io.netty.handler.codec.http.FullHttpResponse;
 import javax.inject.Inject;
 import javax.inject.Singleton;
@@ -112,9 +111,9 @@ public class BackendMetrics {
   }
 
   @NonFinalForTesting
-  public void requestSent(String protocol, String certHash, FullHttpRequest request) {
+  public void requestSent(String protocol, String certHash, int bytes) {
     requestsCounter.increment(protocol, certHash);
-    requestBytes.record(request.content().readableBytes(), protocol, certHash);
+    requestBytes.record(bytes, protocol, certHash);
   }
 
   @NonFinalForTesting
diff --git a/javatests/google/registry/proxy/handler/BackendMetricsHandlerTest.java b/javatests/google/registry/proxy/handler/BackendMetricsHandlerTest.java
index 58a09495a..1a34644e4 100644
--- a/javatests/google/registry/proxy/handler/BackendMetricsHandlerTest.java
+++ b/javatests/google/registry/proxy/handler/BackendMetricsHandlerTest.java
@@ -114,7 +114,8 @@ public class BackendMetricsHandlerTest {
     // outbound message passed to the next handler.
     assertThat(channel.writeOutbound(request)).isTrue();
     assertHttpRequestEquivalent(request, channel.readOutbound());
-    verify(metrics).requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request);
+    verify(metrics)
+        .requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request.content().readableBytes());
     verifyNoMoreInteractions(metrics);
   }
 
@@ -130,7 +131,8 @@ public class BackendMetricsHandlerTest {
     assertThat(channel.writeInbound(response)).isTrue();
     assertHttpResponseEquivalent(response, channel.readInbound());
 
-    verify(metrics).requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request);
+    verify(metrics)
+        .requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request.content().readableBytes());
     verify(metrics).responseReceived(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, response, 1);
     verifyNoMoreInteractions(metrics);
   }
@@ -150,7 +152,8 @@ public class BackendMetricsHandlerTest {
     assertThat(channel.writeInbound(response)).isTrue();
     assertHttpResponseEquivalent(response, channel.readInbound());
 
-    verify(metrics).requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request);
+    verify(metrics)
+        .requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request.content().readableBytes());
     verify(metrics).responseReceived(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, response, 1);
     verifyNoMoreInteractions(metrics);
   }
@@ -167,10 +170,10 @@ public class BackendMetricsHandlerTest {
   public void testSuccess_pipelinedResponses() {
     FullHttpRequest request1 = makeHttpPostRequest("request 1", HOST, "/");
     FullHttpResponse response1 = makeHttpResponse("response 1", HttpResponseStatus.OK);
-    FullHttpRequest request2 = makeHttpPostRequest("request 2", HOST, "/");
-    FullHttpResponse response2 = makeHttpResponse("response 2", HttpResponseStatus.OK);
-    FullHttpRequest request3 = makeHttpPostRequest("request 3", HOST, "/");
-    FullHttpResponse response3 = makeHttpResponse("response 3", HttpResponseStatus.OK);
+    FullHttpRequest request2 = makeHttpPostRequest("request 22", HOST, "/");
+    FullHttpResponse response2 = makeHttpResponse("response 22", HttpResponseStatus.OK);
+    FullHttpRequest request3 = makeHttpPostRequest("request 333", HOST, "/");
+    FullHttpResponse response3 = makeHttpResponse("response 333", HttpResponseStatus.OK);
 
     // First request, time = 0
     assertThat(channel.writeOutbound(request1)).isTrue();
@@ -216,9 +219,12 @@ public class BackendMetricsHandlerTest {
     long latency2 = new Duration(sentTime2, receivedTime2).getMillis();
     long latency3 = new Duration(sentTime3, receivedTime3).getMillis();
 
-    verify(metrics).requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request1);
-    verify(metrics).requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request2);
-    verify(metrics).requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request3);
+    verify(metrics)
+        .requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request1.content().readableBytes());
+    verify(metrics)
+        .requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request2.content().readableBytes());
+    verify(metrics)
+        .requestSent(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, request3.content().readableBytes());
     verify(metrics).responseReceived(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, response1, latency1);
     verify(metrics).responseReceived(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, response2, latency2);
     verify(metrics).responseReceived(RELAYED_PROTOCOL_NAME, CLIENT_CERT_HASH, response3, latency3);
diff --git a/javatests/google/registry/proxy/metric/BackendMetricsTest.java b/javatests/google/registry/proxy/metric/BackendMetricsTest.java
index db7d021fe..ea6dfd7b9 100644
--- a/javatests/google/registry/proxy/metric/BackendMetricsTest.java
+++ b/javatests/google/registry/proxy/metric/BackendMetricsTest.java
@@ -47,7 +47,7 @@ public class BackendMetricsTest {
   public void testSuccess_oneRequest() {
     String content = "some content";
     FullHttpRequest request = makeHttpPostRequest(content, host, "/");
-    metrics.requestSent(protocol, certHash, request);
+    metrics.requestSent(protocol, certHash, request.content().readableBytes());
 
     assertThat(BackendMetrics.requestsCounter)
         .hasValueForLabels(1, protocol, certHash)
@@ -68,8 +68,8 @@ public class BackendMetricsTest {
     String content2 = "some other content";
     FullHttpRequest request1 = makeHttpPostRequest(content1, host, "/");
     FullHttpRequest request2 = makeHttpPostRequest(content2, host, "/");
-    metrics.requestSent(protocol, certHash, request1);
-    metrics.requestSent(protocol, certHash, request2);
+    metrics.requestSent(protocol, certHash, request1.content().readableBytes());
+    metrics.requestSent(protocol, certHash, request2.content().readableBytes());
 
     assertThat(BackendMetrics.requestsCounter)
         .hasValueForLabels(2, protocol, certHash)
@@ -146,7 +146,7 @@ public class BackendMetricsTest {
     String responseContent = "the only response";
     FullHttpRequest request = makeHttpPostRequest(requestContent, host, "/");
     FullHttpResponse response = makeHttpResponse(responseContent, HttpResponseStatus.OK);
-    metrics.requestSent(protocol, certHash, request);
+    metrics.requestSent(protocol, certHash, request.content().readableBytes());
     metrics.responseReceived(protocol, certHash, response, 10);
 
     assertThat(BackendMetrics.requestsCounter)