feat: increase default number of channels when gRPC-GCP channel pool is enabled

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

@@ -696,6 +696,7 @@ public static class Builder
  private CloseableExecutorProvider asyncExecutorProvider;
  private String compressorName;
  private String emulatorHost = System.getenv("SPANNER_EMULATOR_HOST");
+ private boolean userSpecifiedNumChannels = false;
 
  private Builder() {
  // Manually set retry and polling settings that work.
@@ -815,6 +816,7 @@ public Builder setInterceptorProvider(GrpcInterceptorProvider interceptorProvide
  */
  public Builder setNumChannels(int numChannels) {
  this.numChannels = numChannels;
+ this.userSpecifiedNumChannels = true;
  return this;
  }
 
@@ -1123,6 +1125,9 @@ public Builder setHost(String host) {
  /** Enables gRPC-GCP extension with the default settings. */
  public Builder enableGrpcGcpExtension() {
  this.grpcGcpExtensionEnabled = true;
+ if (!userSpecifiedNumChannels) { // If numChannels is not set through options
+ this.numChannels = 8; // default when grpc-gcp channel pool is enabled
+ }
  return this;
  }
 

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

@@ -0,0 +1,64 @@
+package com.google.cloud.spanner;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class DefaultNumChannelsTest {
+
+ // With GRPC GCP channel pool enabled
+ @Test
+ public void testDefaultNumChannelsWithGrpcGcpEnabled() {
+ SpannerOptions.Builder builder = SpannerOptions.newBuilder()
+ .setProjectId("test-project")
+ .enableGrpcGcpExtension();
+
+ SpannerOptions options = builder.build();
+ assertThat(options.getNumChannels()).isEqualTo(8);
+ }
+
+ @Test
+ public void testNumChannelsWithGrpcGcpEnabledLater() {
+ SpannerOptions.Builder builder = SpannerOptions.newBuilder()
+ .setProjectId("test-project")
+ .setNumChannels(5)
+ .enableGrpcGcpExtension();
+
+ SpannerOptions options = builder.build();
+ assertThat(options.getNumChannels()).isEqualTo(5);
+ }
+
+ @Test
+ public void testNumChannelsWithGrpcGcpEnabled() {
+ SpannerOptions.Builder builder = SpannerOptions.newBuilder()
+ .setProjectId("test-project")
+ .enableGrpcGcpExtension()
+ .setNumChannels(5);
+
+ SpannerOptions options = builder.build();
+ assertThat(options.getNumChannels()).isEqualTo(5);
+ }
+
+ // Without enabling GRPC GCP channel pool
+ @Test
+ public void testDefaultNumChannelsWithOutGrpcGcpEnabled() {
+ SpannerOptions.Builder builder = SpannerOptions.newBuilder()
+ .setProjectId("test-project");
+
+ SpannerOptions options = builder.build();
+ assertThat(options.getNumChannels()).isEqualTo(4);
+ }
+
+ @Test
+ public void testNumChannelsWithOutGrpcGcpEnabled() {
+ SpannerOptions.Builder builder = SpannerOptions.newBuilder()
+ .setProjectId("test-project")
+ .setNumChannels(7);
+
+ SpannerOptions options = builder.build();
+ assertThat(options.getNumChannels()).isEqualTo(7);
+ }
+}