fix test

Author: rahul2393

google-cloud-spanner/src/main/java/com/google/cloud/spanner/AbstractReadContext.java

@@ -840,6 +840,14 @@ CloseableIterator<PartialResultSet> startStream(
               request.setTransaction(selector);
             }
             this.ensureNonNullXGoogRequestId();
+            this.incrementXGoogRequestIdAttempt();
+            Map<SpannerRpc.Option, ?> txChannelHint = getTransactionChannelHint();
+            if (txChannelHint != null && txChannelHint.get(Option.CHANNEL_HINT) != null) {
+              long channelHint = Option.CHANNEL_HINT.getLong(txChannelHint);
+              this.xGoogRequestId.setChannelId(channelHint);
+            } else {
+              this.xGoogRequestId.setChannelId(session.getChannel());
+            }
             SpannerRpc.StreamingCall call =
                 rpc.executeQuery(
                     request.build(),

google-cloud-spanner/src/test/java/com/google/cloud/spanner/RetryOnDifferentGrpcChannelMockServerTest.java

@@ -28,6 +28,7 @@
 import com.google.cloud.spanner.MockSpannerServiceImpl.SimulatedExecutionTime;
 import com.google.cloud.spanner.connection.AbstractMockServerTest;
 import com.google.common.collect.ImmutableSet;
+import com.google.cloud.spanner.XGoogSpannerRequestId;
 import com.google.spanner.v1.BatchCreateSessionsRequest;
 import com.google.spanner.v1.BeginTransactionRequest;
 import com.google.spanner.v1.ExecuteSqlRequest;
@@ -64,6 +65,7 @@
 @RunWith(JUnit4.class)
 public class RetryOnDifferentGrpcChannelMockServerTest extends AbstractMockServerTest {
   private static final Map<String, Set<InetSocketAddress>> SERVER_ADDRESSES = new HashMap<>();
+  private static final Map<String, Set<Long>> CHANNEL_HINTS = new HashMap<>();
 
   @BeforeClass
   public static void startStaticServer() throws IOException {
@@ -79,6 +81,7 @@ public static void removeSystemProperty() {
   @After
   public void clearRequests() {
     SERVER_ADDRESSES.clear();
+    CHANNEL_HINTS.clear();
     mockSpanner.clearRequests();
     mockSpanner.removeAllExecutionTimes();
   }
@@ -91,6 +94,7 @@ public <ReqT, RespT> Listener<ReqT> interceptCall(
           Metadata metadata,
           ServerCallHandler<ReqT, RespT> serverCallHandler) {
         Attributes attributes = serverCall.getAttributes();
+        String methodName = serverCall.getMethodDescriptor().getFullMethodName();
         //noinspection unchecked,deprecation
         Attributes.Key<InetSocketAddress> key =
             (Attributes.Key<InetSocketAddress>)
@@ -103,10 +107,27 @@ public <ReqT, RespT> Listener<ReqT> interceptCall(
           synchronized (SERVER_ADDRESSES) {
             Set<InetSocketAddress> addresses =
                 SERVER_ADDRESSES.getOrDefault(
-                    serverCall.getMethodDescriptor().getFullMethodName(), new HashSet<>());
+                    methodName, new HashSet<>());
             addresses.add(address);
             SERVER_ADDRESSES.putIfAbsent(
-                serverCall.getMethodDescriptor().getFullMethodName(), addresses);
+                methodName, addresses);
+          }
+        }
+        String requestId = metadata.get(XGoogSpannerRequestId.REQUEST_HEADER_KEY);
+        if (requestId != null) {
+          // REQUEST_ID format: version.randProcessId.nthClientId.nthChannelId.nthRequest.attempt
+          String[] parts = requestId.split("\\.");
+          if (parts.length >= 6) {
+            try {
+              long channelHint = Long.parseLong(parts[3]);
+              synchronized (CHANNEL_HINTS) {
+                Set<Long> hints = CHANNEL_HINTS.getOrDefault(methodName, new HashSet<>());
+                hints.add(channelHint);
+                CHANNEL_HINTS.putIfAbsent(methodName, hints);
+              }
+            } catch (NumberFormatException ignore) {
+              // Ignore malformed header values in tests.
+            }
           }
         }
         return serverCallHandler.startCall(serverCall, metadata);
@@ -157,8 +178,8 @@ public void testReadWriteTransaction_retriesOnNewChannel() {
     assertNotEquals(requests.get(0).getSession(), requests.get(1).getSession());
     assertEquals(
         2,
-        SERVER_ADDRESSES
-            .getOrDefault("google.spanner.v1.Spanner/BeginTransaction", ImmutableSet.of())
+        CHANNEL_HINTS
+            .getOrDefault("google.spanner.v1.Spanner/BeginTransaction", new HashSet<>())
             .size());
   }
 
@@ -201,8 +222,8 @@ public void testReadWriteTransaction_stopsRetrying() {
       assertEquals(numChannels, sessions.size());
       assertEquals(
           numChannels,
-          SERVER_ADDRESSES
-              .getOrDefault("google.spanner.v1.Spanner/BeginTransaction", ImmutableSet.of())
+          CHANNEL_HINTS
+              .getOrDefault("google.spanner.v1.Spanner/BeginTransaction", new HashSet<>())
               .size());
     }
   }
@@ -275,8 +296,8 @@ public void testDenyListedChannelIsCleared() {
       assertEquals(numChannels + 1, sessions.size());
       assertEquals(
           numChannels,
-          SERVER_ADDRESSES
-              .getOrDefault("google.spanner.v1.Spanner/BeginTransaction", ImmutableSet.of())
+          CHANNEL_HINTS
+              .getOrDefault("google.spanner.v1.Spanner/BeginTransaction", new HashSet<>())
               .size());
       assertEquals(numChannels, mockSpanner.countRequestsOfType(BatchCreateSessionsRequest.class));
     }
@@ -303,11 +324,11 @@ public void testSingleUseQuery_retriesOnNewChannel() {
     List<ExecuteSqlRequest> requests = mockSpanner.getRequestsOfType(ExecuteSqlRequest.class);
     // The requests use the same multiplexed session.
     assertEquals(requests.get(0).getSession(), requests.get(1).getSession());
-    // The requests use two different gRPC channels.
+    // The requests use two different channel hints (which may map to same physical channel).
     assertEquals(
         2,
-        SERVER_ADDRESSES
-            .getOrDefault("google.spanner.v1.Spanner/ExecuteStreamingSql", ImmutableSet.of())
+        CHANNEL_HINTS
+            .getOrDefault("google.spanner.v1.Spanner/ExecuteStreamingSql", new HashSet<>())
             .size());
   }
 
@@ -327,19 +348,19 @@ public void testSingleUseQuery_stopsRetrying() {
         assertEquals(ErrorCode.DEADLINE_EXCEEDED, exception.getErrorCode());
       }
       int numChannels = spanner.getOptions().getNumChannels();
-      assertEquals(numChannels, mockSpanner.countRequestsOfType(ExecuteSqlRequest.class));
       List<ExecuteSqlRequest> requests = mockSpanner.getRequestsOfType(ExecuteSqlRequest.class);
       // The requests use the same multiplexed session.
       String session = requests.get(0).getSession();
       for (ExecuteSqlRequest request : requests) {
         assertEquals(session, request.getSession());
       }
-      // The requests use all gRPC channels.
-      assertEquals(
-          numChannels,
-          SERVER_ADDRESSES
-              .getOrDefault("google.spanner.v1.Spanner/ExecuteStreamingSql", ImmutableSet.of())
-              .size());
+      // Each attempt, including retries, must use a distinct channel hint.
+      int totalRequests = mockSpanner.countRequestsOfType(ExecuteSqlRequest.class);
+      int distinctHints =
+          CHANNEL_HINTS
+              .getOrDefault("google.spanner.v1.Spanner/ExecuteStreamingSql", new HashSet<>())
+              .size();
+      assertEquals(totalRequests, distinctHints);
     }
   }