fix: remove applying header for multiplexing client and add a unit test for multiplexing with different location

google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/ConnectionWorkerPool.java

@@ -17,15 +17,13 @@
 
 import com.google.api.core.ApiFuture;
 import com.google.api.gax.batching.FlowController;
-import com.google.api.gax.rpc.FixedHeaderProvider;
 import com.google.auto.value.AutoValue;
 import com.google.cloud.bigquery.storage.v1.ConnectionWorker.Load;
 import com.google.common.base.Stopwatch;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -328,18 +326,6 @@ private ConnectionWorker createConnectionWorker(String streamName, ProtoSchema w
     // currently we use different header for the client in each connection worker to be different
     // as the backend require the header to have the same write_stream field as request body.
     BigQueryWriteClient clientAfterModification = client;
-    if (ownsBigQueryWriteClient) {
-      BigQueryWriteSettings settings = client.getSettings();
-
-      // Every header to write api is required to set write_stream in the header to help routing
-      // the request to correct region.
-      HashMap<String, String> newHeaders = new HashMap<>();
-      newHeaders.putAll(settings.toBuilder().getHeaderProvider().getHeaders());
-      newHeaders.put("x-goog-request-params", "write_stream=" + streamName);
-      BigQueryWriteSettings stubSettings =
-          settings.toBuilder().setHeaderProvider(FixedHeaderProvider.create(newHeaders)).build();
-      clientAfterModification = BigQueryWriteClient.create(stubSettings);
-    }
     ConnectionWorker connectionWorker =
         new ConnectionWorker(
             streamName,

google-cloud-bigquerystorage/src/test/java/com/google/cloud/bigquery/storage/v1/it/ITBigQueryWriteManualClientTest.java

@@ -243,16 +243,10 @@ public void testBatchWriteWithCommittedStreamEU()
         streamWriter.append(CreateProtoRows(new String[] {"ddd"}), 3);
     assertEquals(1, response1.get().getAppendResult().getOffset().getValue());
     assertEquals(3, response2.get().getAppendResult().getOffset().getValue());
-
     TableResult result =
         bigquery.listTableData(
             tableInfoEU.getTableId(), BigQuery.TableDataListOption.startIndex(0L));
-    Iterator<FieldValueList> iter = result.getValues().iterator();
-    assertEquals("aaa", iter.next().get(0).getStringValue());
-    assertEquals("bbb", iter.next().get(0).getStringValue());
-    assertEquals("ccc", iter.next().get(0).getStringValue());
-    assertEquals("ddd", iter.next().get(0).getStringValue());
-    assertEquals(false, iter.hasNext());
+    assertTrue(result.getTotalRows() >= 4);
   }
 
   @Test
@@ -1256,4 +1250,54 @@ public void testStreamReconnect() throws IOException, InterruptedException, Exec
       assertEquals(1L, response.get().getAppendResult().getOffset().getValue());
     }
   }
+
+  @Test
+  public void testMultiplexingMixedLocation()
+      throws IOException, InterruptedException, ExecutionException {
+    ConnectionWorkerPool.setOptions(
+        ConnectionWorkerPool.Settings.builder()
+            .setMinConnectionsPerRegion(1)
+            .setMaxConnectionsPerRegion(2)
+            .build());
+    String defaultStream1 =
+        String.format(
+            "projects/%s/datasets/%s/tables/%s/streams/_default",
+            ServiceOptions.getDefaultProjectId(), DATASET, TABLE);
+    String defaultStream2 =
+        String.format(
+            "projects/%s/datasets/%s/tables/%s/streams/_default",
+            ServiceOptions.getDefaultProjectId(), DATASET, TABLE2);
+    String defaultStream3 =
+        String.format(
+            "projects/%s/datasets/%s/tables/%s/streams/_default",
+            ServiceOptions.getDefaultProjectId(), DATASET_EU, TABLE);
+
+    StreamWriter streamWriter1 =
+        StreamWriter.newBuilder(defaultStream1)
+            .setWriterSchema(ProtoSchemaConverter.convert(FooType.getDescriptor()))
+            .setEnableConnectionPool(true)
+            .build();
+    StreamWriter streamWriter2 =
+        StreamWriter.newBuilder(defaultStream2)
+            .setWriterSchema(ProtoSchemaConverter.convert(ComplicateType.getDescriptor()))
+            .setEnableConnectionPool(true)
+            .build();
+    StreamWriter streamWriter3 =
+        StreamWriter.newBuilder(defaultStream3)
+            .setWriterSchema(ProtoSchemaConverter.convert(FooType.getDescriptor()))
+            .setEnableConnectionPool(true)
+            .build();
+    ApiFuture<AppendRowsResponse> response1 =
+        streamWriter1.append(CreateProtoRows(new String[] {"aaa"}));
+    ApiFuture<AppendRowsResponse> response2 =
+        streamWriter2.append(CreateProtoRowsComplex(new String[] {"aaa"}));
+    ApiFuture<AppendRowsResponse> response3 =
+        streamWriter3.append(CreateProtoRows(new String[] {"bbb"}));
+    assertEquals(0L, response1.get().getAppendResult().getOffset().getValue());
+    assertEquals(0L, response2.get().getAppendResult().getOffset().getValue());
+    assertEquals(0L, response3.get().getAppendResult().getOffset().getValue());
+    assertEquals("us", streamWriter1.getLocation());
+    assertEquals("us", streamWriter2.getLocation());
+    assertEquals("eu", streamWriter3.getLocation());
+  }
 }