Improve testTransportStatsWithException test (#28554)

This commit modifies the transport stats with exception test to remove
the requirement that we calculate the published address size when
comparing bytes received. This is tricky and is currently broken as we
also place the address string in the transport exception, however we do
not adjust the bytes for that.

The solution in this commit is to just serialize the transport exception
in the test and use that for the calculation.

test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java

@@ -30,7 +30,9 @@ import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListenerResponseHandler;
 import org.elasticsearch.action.support.PlainActionFuture;
 import org.elasticsearch.cluster.node.DiscoveryNode;
+import org.elasticsearch.common.io.stream.BytesStreamOutput;
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
+import org.elasticsearch.common.io.stream.ReleasableBytesStreamOutput;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.network.NetworkService;
@@ -2390,6 +2392,7 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
         serviceC.start();
         serviceC.acceptIncomingRequests();
         CountDownLatch responseLatch = new CountDownLatch(1);
+        AtomicReference<TransportException> receivedException = new AtomicReference<>(null);
         TransportResponseHandler<TransportResponse> transportResponseHandler = new TransportResponseHandler<TransportResponse>() {
             @Override
             public TransportResponse newInstance() {
@@ -2403,6 +2406,7 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
             @Override
             public void handleException(TransportException exp) {
+                receivedException.set(exp);
                 responseLatch.countDown();
             }
 
@@ -2427,7 +2431,7 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
             TransportRequestOptions.Type.STATE);
         try (Transport.Connection connection = serviceC.openConnection(serviceB.getLocalNode(), builder.build())) {
             assertBusy(() -> { // netty for instance invokes this concurrently so we better use assert busy here
-                TransportStats transportStats = serviceC.transport.getStats(); // request has ben send
+                TransportStats transportStats = serviceC.transport.getStats(); // request has been sent
                 assertEquals(1, transportStats.getRxCount());
                 assertEquals(1, transportStats.getTxCount());
                 assertEquals(25, transportStats.getRxSize().getBytes());
@@ -2437,7 +2441,7 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
                 transportResponseHandler);
             receivedLatch.await();
             assertBusy(() -> { // netty for instance invokes this concurrently so we better use assert busy here
-                TransportStats transportStats = serviceC.transport.getStats(); // request has ben send
+                TransportStats transportStats = serviceC.transport.getStats(); // request has been sent
                 assertEquals(1, transportStats.getRxCount());
                 assertEquals(2, transportStats.getTxCount());
                 assertEquals(25, transportStats.getRxSize().getBytes());
@@ -2448,10 +2452,14 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
             stats = serviceC.transport.getStats(); // exception response has been received
             assertEquals(2, stats.getRxCount());
             assertEquals(2, stats.getTxCount());
-            int addressLen = serviceB.boundAddress().publishAddress().address().getAddress().getAddress().length;
+            TransportException exception = receivedException.get();
-            // if we are bound to a IPv6 address the response address is serialized with the exception so it will be different depending
+            assertNotNull(exception);
-            // on the stack. The emphemeral port will always be in the same range
+            BytesStreamOutput streamOutput = new BytesStreamOutput();
-            assertEquals(183 + addressLen, stats.getRxSize().getBytes());
+            exception.writeTo(streamOutput);
+            String failedMessage = "Unexpected read bytes size. The transport exception that was received=" + exception;
+            // 49 bytes are the non-exception message bytes that have been received. It should include the initial
+            // handshake message and the header, version, etc bytes in the exception message.
+            assertEquals(failedMessage, 49 + streamOutput.bytes().length(), stats.getRxSize().getBytes());
             assertEquals(91, stats.getTxSize().getBytes());
         } finally {
             serviceC.close();