Add load test for cross db txn

v2/datastream-to-spanner/src/test/java/com/google/cloud/teleport/v2/templates/loadtesting/DataStreamToSpanner100GbLT.java

@@ -53,4 +53,28 @@ public void backfill100Gb() throws IOException, ParseException, InterruptedExcep
     JDBCSource mySQLSource = getMySQLSource(hostIp, username, password);
     runLoadTest(tables100GB, mySQLSource);
   }
+
+  @Test
+  public void crossDbTxn_backfill100Gb() throws IOException, ParseException, InterruptedException {
+    setUpResourceManagers(
+        "DataStreamToSpanner100GbLT/spanner-schema.sql", /* separateShadowTableDb= */ true);
+    HashMap<String, Integer> tables100GB = new HashMap<>();
+    for (int i = 1; i <= 10; i++) {
+      tables100GB.put("person" + i, 6500000);
+    }
+
+    // Setup Datastream
+    String hostIp =
+        secretClient.accessSecret(
+            "projects/269744978479/secrets/nokill-datastream-mysql-to-spanner-cloudsql-ip-address/versions/1");
+    String username =
+        secretClient.accessSecret(
+            "projects/269744978479/secrets/nokill-datastream-mysql-to-spanner-cloudsql-username/versions/1");
+    String password =
+        secretClient.accessSecret(
+            "projects/269744978479/secrets/nokill-datastream-mysql-to-spanner-cloudsql-password/versions/1");
+
+    JDBCSource mySQLSource = getMySQLSource(hostIp, username, password);
+    runLoadTest(tables100GB, mySQLSource);
+  }
 }

v2/datastream-to-spanner/src/test/java/com/google/cloud/teleport/v2/templates/loadtesting/DataStreamToSpannerLTBase.java

@@ -69,16 +69,22 @@ public class DataStreamToSpannerLTBase extends TemplateLoadTestBase {
   protected final int numWorkers = 50;
   public PubsubResourceManager pubsubResourceManager;
   public SpannerResourceManager spannerResourceManager;
+  protected SpannerResourceManager shadowTableSpannerResourceManager = null;
   protected GcsResourceManager gcsResourceManager;
   public DatastreamResourceManager datastreamResourceManager;
   protected SecretManagerResourceManager secretClient;
 
+  public void setUpResourceManagers(String spannerDdlResource) throws IOException {
+    setUpResourceManagers(spannerDdlResource, false);
+  }
+
   /**
    * Setup resource managers.
    *
    * @throws IOException
    */
-  public void setUpResourceManagers(String spannerDdlResource) throws IOException {
+  public void setUpResourceManagers(String spannerDdlResource, boolean separateShadowTableDb)
+      throws IOException {
     testRootDir = getClass().getSimpleName();
     spannerResourceManager =
         SpannerResourceManager.builder(testName, project, region)
@@ -98,6 +104,18 @@ public void setUpResourceManagers(String spannerDdlResource) throws IOException
             .setCredentialsProvider(CREDENTIALS_PROVIDER)
             .build();
     secretClient = SecretManagerResourceManager.builder(project, CREDENTIALS_PROVIDER).build();
+
+    // Initialize shadowTableSpannerResourceManager only if separateShadowTableDb is true
+    if (separateShadowTableDb) {
+      shadowTableSpannerResourceManager =
+          SpannerResourceManager.builder("shadow_" + testName, project, region)
+              .maybeUseStaticInstance()
+              .setNodeCount(10)
+              .setMonitoringClient(monitoringClient)
+              .build();
+      shadowTableSpannerResourceManager.ensureUsableAndCreateResources();
+    }
+
     createSpannerDDL(spannerResourceManager, spannerDdlResource);
   }
 
@@ -148,6 +166,21 @@ public void runLoadTest(
             put("inputFileFormat", "avro");
           }
         };
+
+    // Add shadow table parameters if shadowTableSpannerResourceManager is not null
+    if (shadowTableSpannerResourceManager != null) {
+      params.putAll(
+          new HashMap<>() {
+            {
+              put(
+                  "shadowTableSpannerInstanceId",
+                  shadowTableSpannerResourceManager.getInstanceId());
+              put(
+                  "shadowTableSpannerDatabaseId",
+                  shadowTableSpannerResourceManager.getDatabaseId());
+            }
+          });
+    }
     // Add all parameters for the template
     params.putAll(templateParameters);
 
@@ -206,6 +239,7 @@ public void cleanUp() throws IOException {
     ResourceManagerUtils.cleanResources(
         secretClient,
         spannerResourceManager,
+        shadowTableSpannerResourceManager,
         pubsubResourceManager,
         gcsResourceManager,
         datastreamResourceManager);