feat: remove grpclb (#2760)

* chore: add DirectPath fallback integration test

* feat: remove grpclb

* feat: remove grpclb

* feat: remove grpclb

* feat: remove grpclb

---------

Co-authored-by: Knut Olav Løite <[email protected]>

Author: mohanli-ml

google-cloud-spanner/pom.xml

@@ -151,7 +151,7 @@
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-dependency-plugin</artifactId>
           <configuration>
-            <ignoredDependencies>io.grpc:grpc-protobuf-lite,org.hamcrest:hamcrest,org.hamcrest:hamcrest-core,com.google.errorprone:error_prone_annotations,org.openjdk.jmh:jmh-generator-annprocess,com.google.api.grpc:grpc-google-cloud-spanner-v1,com.google.api.grpc:grpc-google-cloud-spanner-admin-instance-v1,com.google.api.grpc:grpc-google-cloud-spanner-admin-database-v1,javax.annotation:javax.annotation-api,io.opencensus:opencensus-impl,org.graalvm.sdk:graal-sdk,io.grpc:grpc-grpclb,io.grpc:grpc-googleapis,io.grpc:grpc-rls,com.google.api.grpc:proto-google-cloud-spanner-executor-v1,com.google.api.grpc:grpc-google-cloud-spanner-executor-v1</ignoredDependencies>
+            <ignoredDependencies>io.grpc:grpc-protobuf-lite,org.hamcrest:hamcrest,org.hamcrest:hamcrest-core,com.google.errorprone:error_prone_annotations,org.openjdk.jmh:jmh-generator-annprocess,com.google.api.grpc:grpc-google-cloud-spanner-v1,com.google.api.grpc:grpc-google-cloud-spanner-admin-instance-v1,com.google.api.grpc:grpc-google-cloud-spanner-admin-database-v1,javax.annotation:javax.annotation-api,io.opencensus:opencensus-impl,org.graalvm.sdk:graal-sdk,io.grpc:grpc-googleapis,io.grpc:grpc-rls,com.google.api.grpc:proto-google-cloud-spanner-executor-v1,com.google.api.grpc:grpc-google-cloud-spanner-executor-v1</ignoredDependencies>
           </configuration>
         </plugin>
       </plugins>
@@ -325,11 +325,6 @@
       <groupId>io.grpc</groupId>
       <artifactId>grpc-alts</artifactId>
     </dependency>
-    <dependency>
-      <groupId>io.grpc</groupId>
-      <artifactId>grpc-grpclb</artifactId>
-      <scope>runtime</scope>
-    </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-googleapis</artifactId>

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java

@@ -54,7 +54,6 @@
 import com.google.api.gax.rpc.UnavailableException;
 import com.google.api.gax.rpc.WatchdogProvider;
 import com.google.api.pathtemplate.PathTemplate;
-import com.google.cloud.NoCredentials;
 import com.google.cloud.RetryHelper;
 import com.google.cloud.RetryHelper.RetryHelperException;
 import com.google.cloud.grpc.GcpManagedChannelBuilder;
@@ -344,19 +343,11 @@ public GapicSpannerRpc(final SpannerOptions options) {
                       // This sets the response compressor (Server -> Client).
                       .withEncoding(compressorName))
               .setHeaderProvider(headerProviderWithUserAgent)
-              .setAllowNonDefaultServiceAccount(true)
-              // Attempts direct access to spanner service over gRPC to improve throughput,
-              // whether the attempt is allowed is totally controlled by service owner.
-              // We'll only attempt DirectPath if we are using real credentials.
-              // NoCredentials is used for plain text connections, for example when connecting to
-              // the emulator.
-              .setAttemptDirectPath(
-                  options.isAttemptDirectPath()
-                      && !Objects.equals(
-                          options.getScopedCredentials(), NoCredentials.getInstance()));
+              .setAllowNonDefaultServiceAccount(true);
       String directPathXdsEnv = System.getenv("GOOGLE_SPANNER_ENABLE_DIRECT_ACCESS");
       boolean isAttemptDirectPathXds = Boolean.parseBoolean(directPathXdsEnv);
       if (isAttemptDirectPathXds) {
+        defaultChannelProviderBuilder.setAttemptDirectPath(true);
         defaultChannelProviderBuilder.setAttemptDirectPathXds();
       }
       if (options.isUseVirtualThreads()) {

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

@@ -97,6 +97,7 @@ public GceTestEnvConfig() {
       customChannelProviderBuilder
           .setEndpoint(DIRECT_PATH_ENDPOINT)
           .setAttemptDirectPath(true)
+          .setAttemptDirectPathXds()
           .setInterceptorProvider(interceptorProvider);
       builder.setChannelProvider(customChannelProviderBuilder.build());
     }