EnhancedBigtableStubSettings.java

/*
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.cloud.bigtable.data.v2.stub;

import com.google.api.core.BetaApi;
import com.google.api.gax.batching.BatchingCallSettings;
import com.google.api.gax.batching.BatchingSettings;
import com.google.api.gax.batching.FlowControlSettings;
import com.google.api.gax.batching.FlowController.LimitExceededBehavior;
import com.google.api.gax.core.FixedCredentialsProvider;
import com.google.api.gax.core.GoogleCredentialsProvider;
import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
import com.google.api.gax.retrying.RetrySettings;
import com.google.api.gax.rpc.*;
import com.google.api.gax.rpc.StatusCode.Code;
import com.google.auth.Credentials;
import com.google.cloud.bigtable.Version;
import com.google.cloud.bigtable.data.v2.models.ConditionalRowMutation;
import com.google.cloud.bigtable.data.v2.models.KeyOffset;
import com.google.cloud.bigtable.data.v2.models.Query;
import com.google.cloud.bigtable.data.v2.models.ReadModifyWriteRow;
import com.google.cloud.bigtable.data.v2.models.Row;
import com.google.cloud.bigtable.data.v2.models.RowMutation;
import com.google.cloud.bigtable.data.v2.stub.metrics.*;
import com.google.cloud.bigtable.data.v2.stub.mutaterows.MutateRowsBatchingDescriptor;
import com.google.cloud.bigtable.data.v2.stub.readrows.ReadRowsBatchingDescriptor;
import com.google.common.base.MoreObjects;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;
import javax.annotation.Nonnull;
import org.threeten.bp.Duration;

/**
 * Settings class to configure an instance of {@link EnhancedBigtableStub}.
 *
 * <p>Sane defaults are provided for most settings:
 *
 * <ul>
 *   <li>The default service address (bigtable.googleapis.com) and default port (443) are used.
 *   <li>Credentials are acquired automatically through Application Default Credentials.
 *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
 * </ul>
 *
 * <p>The only required setting is the instance name.
 *
 * <p>The builder of this class is recursive, so contained classes are themselves builders. When
 * build() is called, the tree of builders is called to create the complete settings object.
 *
 * <pre>{@code
 * BigtableDataSettings.Builder settingsBuilder = BigtableDataSettings.newBuilder()
 *   .setProjectId("my-project-id")
 *   .setInstanceId("my-instance-id")
 *   .setAppProfileId("default");
 *
 * settingsBuilder.readRowsSettings()
 *  .setRetryableCodes(Code.DEADLINE_EXCEEDED, Code.UNAVAILABLE);
 *
 * BigtableDataSettings settings = builder.build();
 * }</pre>
 */
public class EnhancedBigtableStubSettings extends StubSettings<EnhancedBigtableStubSettings> {
  private static final Logger logger =
      Logger.getLogger(EnhancedBigtableStubSettings.class.getName());

  // The largest message that can be received is a 256 MB ReadRowsResponse.
  private static final int MAX_MESSAGE_SIZE = 256 * 1024 * 1024;
  private static final String SERVER_DEFAULT_APP_PROFILE_ID = "";

  private static final Set<Code> IDEMPOTENT_RETRY_CODES =
      ImmutableSet.of(Code.DEADLINE_EXCEEDED, Code.UNAVAILABLE);

  // Copy of default retrying settings in the yaml
  private static final RetrySettings IDEMPOTENT_RETRY_SETTINGS =
      RetrySettings.newBuilder()
          .setInitialRetryDelay(Duration.ofMillis(10))
          .setRetryDelayMultiplier(2)
          .setMaxRetryDelay(Duration.ofMinutes(1))
          .setInitialRpcTimeout(Duration.ofSeconds(20))
          .setRpcTimeoutMultiplier(1.0)
          .setMaxRpcTimeout(Duration.ofSeconds(20))
          .setTotalTimeout(Duration.ofMinutes(10))
          .build();

  // Allow retrying ABORTED statuses. These will be returned by the server when the client is
  // too slow to read the rows. This makes sense for the java client because retries happen
  // after the row merging logic. Which means that the retry will not be invoked until the
  // current buffered chunks are consumed.
  private static final Set<Code> READ_ROWS_RETRY_CODES =
      ImmutableSet.<Code>builder().addAll(IDEMPOTENT_RETRY_CODES).add(Code.ABORTED).build();

  private static final RetrySettings READ_ROWS_RETRY_SETTINGS =
      RetrySettings.newBuilder()
          .setInitialRetryDelay(Duration.ofMillis(10))
          .setRetryDelayMultiplier(2.0)
          .setMaxRetryDelay(Duration.ofMinutes(1))
          .setMaxAttempts(10)
          .setJittered(true)
          .setInitialRpcTimeout(Duration.ofMinutes(5))
          .setRpcTimeoutMultiplier(2.0)
          .setMaxRpcTimeout(Duration.ofMinutes(5))
          .setTotalTimeout(Duration.ofHours(12))
          .build();

  private static final RetrySettings MUTATE_ROWS_RETRY_SETTINGS =
      RetrySettings.newBuilder()
          .setInitialRetryDelay(Duration.ofMillis(10))
          .setRetryDelayMultiplier(2)
          .setMaxRetryDelay(Duration.ofMinutes(1))
          .setInitialRpcTimeout(Duration.ofMinutes(1))
          .setRpcTimeoutMultiplier(1.0)
          .setMaxRpcTimeout(Duration.ofMinutes(1))
          .setTotalTimeout(Duration.ofMinutes(10))
          .build();

  /**
   * Scopes that are equivalent to JWT's audience.
   *
   * <p>When the credentials provider contains any of these scopes (default behavior) and the
   * application default credentials point to a service account, then OAuth2 tokens will be replaced
   * with JWT tokens. This removes the need for access token refreshes.
   */
  private static final ImmutableList<String> JWT_ENABLED_SCOPES =
      ImmutableList.<String>builder()
          .add("https://www.googleapis.com/auth/bigtable.data")
          .add("https://www.googleapis.com/auth/cloud-bigtable.data")
          .add("https://www.googleapis.com/auth/cloud-platform")
          .build();

  private final String projectId;
  private final String instanceId;
  private final String appProfileId;
  private final boolean isRefreshingChannel;
  private ImmutableList<String> primedTableIds;
  private HeaderTracer headerTracer;

  private final ServerStreamingCallSettings<Query, Row> readRowsSettings;
  private final UnaryCallSettings<Query, Row> readRowSettings;
  private final UnaryCallSettings<String, List<KeyOffset>> sampleRowKeysSettings;
  private final UnaryCallSettings<RowMutation, Void> mutateRowSettings;
  private final BigtableBatchingCallSettings bulkMutateRowsSettings;
  private final BigtableBulkReadRowsCallSettings bulkReadRowsSettings;
  private final UnaryCallSettings<ConditionalRowMutation, Boolean> checkAndMutateRowSettings;
  private final UnaryCallSettings<ReadModifyWriteRow, Row> readModifyWriteRowSettings;

  private EnhancedBigtableStubSettings(Builder builder) {
    super(builder);

    // Since point reads, streaming reads, bulk reads share the same base callable that converts
    // grpc errors into ApiExceptions, they must have the same retry codes.
    Preconditions.checkState(
        builder
            .readRowSettings
            .getRetryableCodes()
            .equals(builder.readRowsSettings.getRetryableCodes()),
        "Single ReadRow retry codes must match ReadRows retry codes");
    Preconditions.checkState(
        builder
            .bulkReadRowsSettings
            .getRetryableCodes()
            .equals(builder.readRowsSettings.getRetryableCodes()),
        "Bulk ReadRow retry codes must match ReadRows retry codes");

    projectId = builder.projectId;
    instanceId = builder.instanceId;
    appProfileId = builder.appProfileId;
    isRefreshingChannel = builder.isRefreshingChannel;
    primedTableIds = builder.primedTableIds;
    headerTracer = builder.headerTracer;

    // Per method settings.
    readRowsSettings = builder.readRowsSettings.build();
    readRowSettings = builder.readRowSettings.build();
    sampleRowKeysSettings = builder.sampleRowKeysSettings.build();
    mutateRowSettings = builder.mutateRowSettings.build();
    bulkMutateRowsSettings = builder.bulkMutateRowsSettings.build();
    bulkReadRowsSettings = builder.bulkReadRowsSettings.build();
    checkAndMutateRowSettings = builder.checkAndMutateRowSettings.build();
    readModifyWriteRowSettings = builder.readModifyWriteRowSettings.build();
  }

  /** Create a new builder. */
  public static Builder newBuilder() {
    return new Builder();
  }

  /** Returns the project id of the target instance. */
  public String getProjectId() {
    return projectId;
  }

  /** Returns the target instance id. */
  public String getInstanceId() {
    return instanceId;
  }

  /** Returns the configured AppProfile to use */
  public String getAppProfileId() {
    return appProfileId;
  }

  /** Returns if channels will gracefully refresh connections to Cloud Bigtable service */
  @BetaApi("This API depends on experimental gRPC APIs")
  public boolean isRefreshingChannel() {
    return isRefreshingChannel;
  }

  /** Gets the tables that will be primed during a channel refresh. */
  @BetaApi("Channel priming is not currently stable and might change in the future")
  public List<String> getPrimedTableIds() {
    return primedTableIds;
  }

  /** Gets the tracer for capturing metrics in the header. */
  @BetaApi("This API is not currently stable and might change in the future")
  public HeaderTracer getHeaderTracer() {
    return headerTracer;
  }

  /** Returns a builder for the default ChannelProvider for this service. */
  public static InstantiatingGrpcChannelProvider.Builder defaultGrpcTransportProviderBuilder() {
    return BigtableStubSettings.defaultGrpcTransportProviderBuilder()
        .setPoolSize(getDefaultChannelPoolSize())
        .setMaxInboundMessageSize(MAX_MESSAGE_SIZE)
        .setKeepAliveTime(Duration.ofSeconds(10)) // sends ping in this interval
        .setKeepAliveTimeout(
            Duration.ofSeconds(10)) // wait this long before considering the connection dead
        .setKeepAliveWithoutCalls(true) // sends ping without active streams
        // Attempts direct access to CBT service over gRPC to improve throughput,
        // whether the attempt is allowed is totally controlled by service owner.
        .setAttemptDirectPath(true)
        .setInterceptorProvider(BigtableInterceptorProvider.createDefault());
  }

  static int getDefaultChannelPoolSize() {
    // TODO: tune channels
    return 2 * Runtime.getRuntime().availableProcessors();
  }

  @SuppressWarnings("WeakerAccess")
  public static TransportChannelProvider defaultTransportChannelProvider() {
    return defaultGrpcTransportProviderBuilder().build();
  }

  /** Returns a builder for the default credentials for this service. */
  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
    return BigtableStubSettings.defaultCredentialsProviderBuilder()
        .setJwtEnabledScopes(JWT_ENABLED_SCOPES);
  }

  /**
   * Returns the object with the settings used for calls to ReadRows.
   *
   * <p>This is idempotent and streaming operation.
   *
   * <p>Default retry and timeout settings:
   *
   * <ul>
   *   <li>{@link ServerStreamingCallSettings.Builder#setIdleTimeout Default idle timeout} is set to
   *       5 mins.
   *   <li>Retry {@link ServerStreamingCallSettings.Builder#setRetryableCodes error codes} are:
   *       {@link Code#DEADLINE_EXCEEDED}, {@link Code#UNAVAILABLE} and {@link Code#ABORTED}.
   *   <li>RetryDelay between failed attempts {@link RetrySettings.Builder#setInitialRetryDelay
   *       starts} at 10ms and {@link RetrySettings.Builder#setRetryDelayMultiplier increases
   *       exponentially} by a factor of 2 until a {@link RetrySettings.Builder#setMaxRetryDelay
   *       maximum of} 1 minute.
   *   <li>The default read timeout for {@link RetrySettings.Builder#setMaxRpcTimeout each row} in a
   *       response stream is 5 minutes with {@link RetrySettings.Builder#setMaxAttempts maximum
   *       attempt} count of 10 times and the timeout to read the {@link
   *       RetrySettings.Builder#setTotalTimeout entire stream} is 12 hours.
   * </ul>
   */
  public ServerStreamingCallSettings<Query, Row> readRowsSettings() {
    return readRowsSettings;
  }

  /**
   * Returns the object with the settings used for calls to SampleRowKeys.
   *
   * <p>This is idempotent and non-streaming operation.
   *
   * <p>Default retry and timeout settings:
   *
   * <ul>
   *   <li>Retry {@link UnaryCallSettings.Builder#setRetryableCodes error codes} are: {@link
   *       Code#DEADLINE_EXCEEDED} and {@link Code#UNAVAILABLE}.
   *   <li>RetryDelay between failed attempts {@link RetrySettings.Builder#setInitialRetryDelay
   *       starts} at 10ms and {@link RetrySettings.Builder#setRetryDelayMultiplier increases
   *       exponentially} by a factor of 2 until a {@link RetrySettings.Builder#setMaxRetryDelay
   *       maximum of} 1 minute.
   *   <li>The default timeout for {@link RetrySettings.Builder#setMaxRpcTimeout each attempt} is 20
   *       seconds and the timeout for the {@link RetrySettings.Builder#setTotalTimeout entire
   *       operation} across all of the attempts is 10 mins.
   * </ul>
   */
  public UnaryCallSettings<String, List<KeyOffset>> sampleRowKeysSettings() {
    return sampleRowKeysSettings;
  }

  /**
   * Returns the object with the settings used for point reads via ReadRows.
   *
   * <p>This is an idempotent and non-streaming operation.
   *
   * <p>Default retry and timeout settings:
   *
   * <ul>
   *   <li>Retry {@link UnaryCallSettings.Builder#setRetryableCodes error codes} are: {@link
   *       Code#DEADLINE_EXCEEDED}, {@link Code#UNAVAILABLE} and {@link Code#ABORTED}.
   *   <li>RetryDelay between failed attempts {@link RetrySettings.Builder#setInitialRetryDelay
   *       starts} at 10ms and {@link RetrySettings.Builder#setRetryDelayMultiplier increases
   *       exponentially} by a factor of 2 until a {@link RetrySettings.Builder#setMaxRetryDelay
   *       maximum of} 1 minute.
   *   <li>The default timeout for {@link RetrySettings.Builder#setMaxRpcTimeout each attempt} is 20
   *       seconds and the timeout for the {@link RetrySettings.Builder#setTotalTimeout entire
   *       operation} across all of the attempts is 10 mins.
   * </ul>
   *
   * @see RetrySettings for more explanation.
   */
  public UnaryCallSettings<Query, Row> readRowSettings() {
    return readRowSettings;
  }

  /**
   * Returns the object with the settings used for calls to MutateRow.
   *
   * <p>This is an idempotent and non-streaming operation.
   *
   * <p>Default retry and timeout settings:
   *
   * <ul>
   *   <li>Retry {@link UnaryCallSettings.Builder#setRetryableCodes error codes} are: {@link
   *       Code#DEADLINE_EXCEEDED} and {@link Code#UNAVAILABLE}.
   *   <li>RetryDelay between failed attempts {@link RetrySettings.Builder#setInitialRetryDelay
   *       starts} at 10ms and {@link RetrySettings.Builder#setRetryDelayMultiplier increases
   *       exponentially} by a factor of 2 until a {@link RetrySettings.Builder#setMaxRetryDelay
   *       maximum of} 60 seconds.
   *   <li>The default timeout for {@link RetrySettings.Builder#setMaxRpcTimeout each attempt} is 20
   *       seconds and the timeout for the {@link RetrySettings.Builder#setTotalTimeout entire
   *       operation} across all of the attempts is 10 mins.
   * </ul>
   *
   * @see RetrySettings for more explanation.
   */
  public UnaryCallSettings<RowMutation, Void> mutateRowSettings() {
    return mutateRowSettings;
  }

  /**
   * Returns the object with the settings used for calls to MutateRows.
   *
   * <p>Please note that these settings will affect both manually batched calls
   * (bulkMutateRowsCallable) and automatic batched calls (bulkMutateRowsBatchingCallable). The
   * {@link RowMutation} request signature is ignored for the manual batched calls.
   *
   * <p>Default retry and timeout settings:
   *
   * <ul>
   *   <li>Retry {@link BatchingCallSettings.Builder#setRetryableCodes error codes} are: {@link
   *       Code#DEADLINE_EXCEEDED} and {@link Code#UNAVAILABLE}.
   *   <li>RetryDelay between failed attempts {@link RetrySettings.Builder#setInitialRetryDelay
   *       starts} at 10ms and {@link RetrySettings.Builder#setRetryDelayMultiplier increases
   *       exponentially} by a factor of 2 until a {@link RetrySettings.Builder#setMaxRetryDelay
   *       maximum of} 1 minute.
   *   <li>The default timeout for {@link RetrySettings.Builder#setMaxRpcTimeout each attempt} is 1
   *       minute and the timeout for the {@link RetrySettings.Builder#setTotalTimeout entire
   *       operation} across all of the attempts is 10 mins.
   * </ul>
   *
   * <p>On breach of certain triggers, the operation initiates processing of accumulated request for
   * which the default settings are:
   *
   * <ul>
   *   <li>When the {@link BatchingSettings.Builder#setElementCountThreshold request count} reaches
   *       100.
   *   <li>When accumulated {@link BatchingSettings.Builder#setRequestByteThreshold request size}
   *       reaches to 20MB.
   *   <li>When an {@link BatchingSettings.Builder#setDelayThreshold interval of} 1 second passes
   *       after batching initialization or last processed batch.
   * </ul>
   *
   * <p>When the pending {@link FlowControlSettings.Builder#setMaxOutstandingElementCount request
   * count} reaches a default of 1000 entries per channel or their {@link
   * FlowControlSettings.Builder#setMaxOutstandingRequestBytes accumulated size} reaches default
   * value of 100MB, then this operation will by default be {@link
   * FlowControlSettings.Builder#setLimitExceededBehavior blocked} until some of the pending batch
   * are resolved.
   *
   * @see RetrySettings for more explanation.
   * @see BatchingSettings for batch related configuration explanation.
   */
  public BigtableBatchingCallSettings bulkMutateRowsSettings() {
    return bulkMutateRowsSettings;
  }

  /**
   * Returns the call settings used for bulk read rows.
   *
   * <p>Default retry and timeout settings:
   *
   * <ul>
   *   <li>Retry {@link BatchingCallSettings.Builder#setRetryableCodes error codes} are: {@link
   *       Code#DEADLINE_EXCEEDED}, {@link Code#UNAVAILABLE} and {@link Code#ABORTED}.
   *   <li>RetryDelay between failed attempts {@link RetrySettings.Builder#setInitialRetryDelay
   *       starts} at 10ms and {@link RetrySettings.Builder#setRetryDelayMultiplier increases
   *       exponentially} by a factor of 2 until a {@link RetrySettings.Builder#setMaxRetryDelay
   *       maximum of} 1 minute.
   *   <li>The default timeout for {@link RetrySettings.Builder#setMaxRpcTimeout each attempt} is 5
   *       minute and the timeout for the {@link RetrySettings.Builder#setTotalTimeout entire
   *       operation} across all of the attempts is 10 mins.
   * </ul>
   *
   * <p>On breach of certain triggers, the operation initiates processing of accumulated request for
   * which the default settings are:
   *
   * <ul>
   *   <li>When the {@link BatchingSettings.Builder#setElementCountThreshold request count} reaches
   *       100.
   *   <li>When accumulated {@link BatchingSettings.Builder#setRequestByteThreshold request size}
   *       reaches to 400KB.
   *   <li>When an {@link BatchingSettings.Builder#setDelayThreshold interval of} 1 second passes
   *       after batching initialization or last processed batch.
   * </ul>
   *
   * <p>When the pending {@link FlowControlSettings.Builder#setMaxOutstandingElementCount request
   * count} reaches a default of 1000 outstanding row keys per channel then this operation will by
   * default be {@link FlowControlSettings.Builder#setLimitExceededBehavior blocked} until some of
   * the pending batch are resolved.
   *
   * @see RetrySettings for more explanation.
   * @see BatchingSettings for batch related configuration explanation.
   */
  public BigtableBulkReadRowsCallSettings bulkReadRowsSettings() {
    return bulkReadRowsSettings;
  }

  /**
   * Returns the object with the settings used for calls to CheckAndMutateRow.
   *
   * <p>This is a non-idempotent and non-streaming operation.
   *
   * <p>By default this operation does not reattempt in case of RPC failure. The default timeout for
   * the {@link RetrySettings.Builder#setTotalTimeout entire operation} is 20 seconds.
   *
   * @see RetrySettings for more explanation.
   */
  public UnaryCallSettings<ConditionalRowMutation, Boolean> checkAndMutateRowSettings() {
    return checkAndMutateRowSettings;
  }

  /**
   * Returns the object with the settings used for calls to ReadModifyWriteRow.
   *
   * <p>This is a non-idempotent and non-streaming operation.
   *
   * <p>By default this operation does not reattempt in case of RPC failure. The default timeout for
   * the {@link RetrySettings.Builder#setTotalTimeout entire operation} is 20 seconds.
   *
   * @see RetrySettings for more explanation.
   */
  public UnaryCallSettings<ReadModifyWriteRow, Row> readModifyWriteRowSettings() {
    return readModifyWriteRowSettings;
  }

  /** Returns a builder containing all the values of this settings class. */
  public Builder toBuilder() {
    return new Builder(this);
  }

  /** Builder for BigtableDataSettings. */
  public static class Builder extends StubSettings.Builder<EnhancedBigtableStubSettings, Builder> {

    private String projectId;
    private String instanceId;
    private String appProfileId;
    private boolean isRefreshingChannel;
    private ImmutableList<String> primedTableIds;
    private HeaderTracer headerTracer;

    private final ServerStreamingCallSettings.Builder<Query, Row> readRowsSettings;
    private final UnaryCallSettings.Builder<Query, Row> readRowSettings;
    private final UnaryCallSettings.Builder<String, List<KeyOffset>> sampleRowKeysSettings;
    private final UnaryCallSettings.Builder<RowMutation, Void> mutateRowSettings;
    private final BigtableBatchingCallSettings.Builder bulkMutateRowsSettings;
    private final BigtableBulkReadRowsCallSettings.Builder bulkReadRowsSettings;
    private final UnaryCallSettings.Builder<ConditionalRowMutation, Boolean>
        checkAndMutateRowSettings;
    private final UnaryCallSettings.Builder<ReadModifyWriteRow, Row> readModifyWriteRowSettings;

    /**
     * Initializes a new Builder with sane defaults for all settings.
     *
     * <p>Most defaults are extracted from BaseBigtableDataSettings, however some of the more
     * complex defaults are configured explicitly here. Once the overlayed defaults are configured,
     * the base settings are augmented to work with overlayed functionality (like disabling retries
     * in the underlying GAPIC client for batching).
     */
    private Builder() {
      this.appProfileId = SERVER_DEFAULT_APP_PROFILE_ID;
      this.isRefreshingChannel = false;
      primedTableIds = ImmutableList.of();
      headerTracer = new HeaderTracer();
      setCredentialsProvider(defaultCredentialsProviderBuilder().build());

      // Defaults provider
      BigtableStubSettings.Builder baseDefaults = BigtableStubSettings.newBuilder();

      setEndpoint(baseDefaults.getEndpoint());

      setTransportChannelProvider(defaultTransportChannelProvider());
      setStreamWatchdogCheckInterval(baseDefaults.getStreamWatchdogCheckInterval());
      setStreamWatchdogProvider(baseDefaults.getStreamWatchdogProvider());

      // Inject the UserAgent in addition to api-client header
      Map<String, String> headers =
          ImmutableMap.<String, String>builder()
              .putAll(
                  BigtableStubSettings.defaultApiClientHeaderProviderBuilder().build().getHeaders())
              // GrpcHeaderInterceptor treats the `user-agent` as a magic string
              .put("user-agent", "bigtable-java/" + Version.VERSION)
              .build();
      setInternalHeaderProvider(FixedHeaderProvider.create(headers));

      // Per-method settings using baseSettings for defaults.
      readRowsSettings = ServerStreamingCallSettings.newBuilder();

      readRowsSettings
          .setRetryableCodes(READ_ROWS_RETRY_CODES)
          .setRetrySettings(READ_ROWS_RETRY_SETTINGS)
          .setIdleTimeout(Duration.ofMinutes(5));

      // Point reads should use same defaults as streaming reads, but with a shorter timeout
      readRowSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
      readRowSettings
          .setRetryableCodes(readRowsSettings.getRetryableCodes())
          .setRetrySettings(
              readRowsSettings()
                  .getRetrySettings()
                  .toBuilder()
                  .setTotalTimeout(IDEMPOTENT_RETRY_SETTINGS.getTotalTimeout())
                  .build());

      sampleRowKeysSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
      sampleRowKeysSettings
          .setRetryableCodes(IDEMPOTENT_RETRY_CODES)
          .setRetrySettings(IDEMPOTENT_RETRY_SETTINGS);

      mutateRowSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
      copyRetrySettings(baseDefaults.mutateRowSettings(), mutateRowSettings);

      long maxBulkMutateElementPerBatch = 100L;
      // Enables bulkMutate to support 10 outstanding batches upto per channel or up to 20K entries.
      long maxBulkMutateOutstandingElementCount =
          Math.min(20_000L, 10L * maxBulkMutateElementPerBatch * getDefaultChannelPoolSize());

      bulkMutateRowsSettings =
          BigtableBatchingCallSettings.newBuilder(new MutateRowsBatchingDescriptor())
              .setRetryableCodes(IDEMPOTENT_RETRY_CODES)
              .setRetrySettings(MUTATE_ROWS_RETRY_SETTINGS)
              .setBatchingSettings(
                  BatchingSettings.newBuilder()
                      .setIsEnabled(true)
                      .setElementCountThreshold(maxBulkMutateElementPerBatch)
                      .setRequestByteThreshold(20L * 1024 * 1024)
                      .setDelayThreshold(Duration.ofSeconds(1))
                      .setFlowControlSettings(
                          FlowControlSettings.newBuilder()
                              .setLimitExceededBehavior(LimitExceededBehavior.Block)
                              .setMaxOutstandingRequestBytes(100L * 1024 * 1024)
                              .setMaxOutstandingElementCount(maxBulkMutateOutstandingElementCount)
                              .build())
                      .build());

      long maxBulkReadElementPerBatch = 100L;
      long maxBulkReadRequestSizePerBatch = 400L * 1024L;
      // Enables bulkRead to support 10 outstanding batches per channel
      long maxBulkReadOutstandingElementCount =
          10L * maxBulkReadElementPerBatch * getDefaultChannelPoolSize();

      bulkReadRowsSettings =
          BigtableBulkReadRowsCallSettings.newBuilder(new ReadRowsBatchingDescriptor())
              .setRetryableCodes(readRowsSettings.getRetryableCodes())
              .setRetrySettings(IDEMPOTENT_RETRY_SETTINGS)
              .setBatchingSettings(
                  BatchingSettings.newBuilder()
                      .setElementCountThreshold(maxBulkReadElementPerBatch)
                      .setRequestByteThreshold(maxBulkReadRequestSizePerBatch)
                      .setDelayThreshold(Duration.ofSeconds(1))
                      .setFlowControlSettings(
                          FlowControlSettings.newBuilder()
                              .setLimitExceededBehavior(LimitExceededBehavior.Block)
                              .setMaxOutstandingElementCount(maxBulkReadOutstandingElementCount)
                              .build())
                      .build());

      checkAndMutateRowSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
      copyRetrySettings(baseDefaults.checkAndMutateRowSettings(), checkAndMutateRowSettings);

      readModifyWriteRowSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
      copyRetrySettings(baseDefaults.readModifyWriteRowSettings(), readModifyWriteRowSettings);
    }

    private Builder(EnhancedBigtableStubSettings settings) {
      super(settings);
      projectId = settings.projectId;
      instanceId = settings.instanceId;
      appProfileId = settings.appProfileId;
      isRefreshingChannel = settings.isRefreshingChannel;
      primedTableIds = settings.primedTableIds;
      headerTracer = settings.headerTracer;

      // Per method settings.
      readRowsSettings = settings.readRowsSettings.toBuilder();
      readRowSettings = settings.readRowSettings.toBuilder();
      sampleRowKeysSettings = settings.sampleRowKeysSettings.toBuilder();
      mutateRowSettings = settings.mutateRowSettings.toBuilder();
      bulkMutateRowsSettings = settings.bulkMutateRowsSettings.toBuilder();
      bulkReadRowsSettings = settings.bulkReadRowsSettings.toBuilder();
      checkAndMutateRowSettings = settings.checkAndMutateRowSettings.toBuilder();
      readModifyWriteRowSettings = settings.readModifyWriteRowSettings.toBuilder();
    }
    // <editor-fold desc="Private Helpers">

    /**
     * Copies settings from unary RPC to another. This is necessary when modifying request and
     * response types while trying to retain retry settings.
     */
    private static void copyRetrySettings(
        UnaryCallSettings.Builder<?, ?> source, UnaryCallSettings.Builder<?, ?> dest) {
      dest.setRetryableCodes(source.getRetryableCodes());
      dest.setRetrySettings(source.getRetrySettings());
    }
    // </editor-fold>

    // <editor-fold desc="Public API">
    /**
     * Sets the project id of that target instance. This setting is required. All RPCs will be made
     * in the context of this setting.
     */
    public Builder setProjectId(@Nonnull String projectId) {
      Preconditions.checkNotNull(projectId);
      this.projectId = projectId;
      return this;
    }

    /** Gets the project id of the target instance that was previously set on this Builder. */
    public String getProjectId() {
      return projectId;
    }

    /**
     * Sets the target instance id. This setting is required. All RPCs will be made in the context
     * of this setting.
     */
    public Builder setInstanceId(@Nonnull String instanceId) {
      Preconditions.checkNotNull(instanceId);
      this.instanceId = instanceId;
      return this;
    }

    /** Gets the target instance id that was previously set on this Builder. */
    public String getInstanceId() {
      return instanceId;
    }

    /**
     * Sets the AppProfile to use. An application profile (sometimes also shortened to "app
     * profile") is a group of configuration parameters for an individual use case. A client will
     * identify itself with an application profile ID at connection time, and the requests will be
     * handled according to that application profile.
     */
    public Builder setAppProfileId(@Nonnull String appProfileId) {
      Preconditions.checkNotNull(appProfileId, "AppProfileId can't be null");
      this.appProfileId = appProfileId;
      return this;
    }

    /**
     * Resets the AppProfile id to the default for the instance.
     *
     * <p>An application profile (sometimes also shortened to "app profile") is a group of
     * configuration parameters for an individual use case. A client will identify itself with an
     * application profile ID at connection time, and the requests will be handled according to that
     * application profile.
     *
     * <p>Every Bigtable Instance has a default application profile associated with it, this method
     * configures the client to use it.
     */
    public Builder setDefaultAppProfileId() {
      setAppProfileId(SERVER_DEFAULT_APP_PROFILE_ID);
      return this;
    }

    /** Gets the app profile id that was previously set on this Builder. */
    public String getAppProfileId() {
      return appProfileId;
    }

    /**
     * Sets if channels will gracefully refresh connections to Cloud Bigtable service.
     *
     * <p>When enabled, this will wait for the connection to complete the SSL handshake. The effect
     * can be enhanced by configuring table ids that can be used warm serverside caches using {@link
     * #setPrimedTableIds(String...)}.
     *
     * @see com.google.cloud.bigtable.data.v2.BigtableDataSettings.Builder#setRefreshingChannel
     */
    @BetaApi("This API depends on experimental gRPC APIs")
    public Builder setRefreshingChannel(boolean isRefreshingChannel) {
      this.isRefreshingChannel = isRefreshingChannel;
      return this;
    }

    /** Configures which tables will be primed when a connection is created. */
    @BetaApi("Channel priming is not currently stable and might change in the future")
    public Builder setPrimedTableIds(String... tableIds) {
      this.primedTableIds = ImmutableList.copyOf(tableIds);
      return this;
    }

    /** Gets if channels will gracefully refresh connections to Cloud Bigtable service */
    @BetaApi("This API depends on experimental gRPC APIs")
    public boolean isRefreshingChannel() {
      return isRefreshingChannel;
    }

    /** Gets the tables that will be primed during a channel refresh. */
    @BetaApi("Channel priming is not currently stable and might change in the future")
    public List<String> getPrimedTableIds() {
      return primedTableIds;
    }

    // TODO: update comments
    /** Configure the header tracer */
    @BetaApi("")
    public Builder setHeaderTracer(HeaderTracer tracer) {
      this.headerTracer = headerTracer;
      return this;
    }

    // TODO: update comments
    public HeaderTracer getHeaderTracer() {
      return headerTracer;
    }

    /** Returns the builder for the settings used for calls to readRows. */
    public ServerStreamingCallSettings.Builder<Query, Row> readRowsSettings() {
      return readRowsSettings;
    }

    /** Returns the builder for the settings used for point reads using readRow. */
    public UnaryCallSettings.Builder<Query, Row> readRowSettings() {
      return readRowSettings;
    }

    /** Returns the builder for the settings used for calls to SampleRowKeysSettings. */
    public UnaryCallSettings.Builder<String, List<KeyOffset>> sampleRowKeysSettings() {
      return sampleRowKeysSettings;
    }

    /** Returns the builder for the settings used for calls to MutateRow. */
    public UnaryCallSettings.Builder<RowMutation, Void> mutateRowSettings() {
      return mutateRowSettings;
    }

    /** Returns the builder for the settings used for calls to MutateRows. */
    public BigtableBatchingCallSettings.Builder bulkMutateRowsSettings() {
      return bulkMutateRowsSettings;
    }

    /** Returns the builder for the settings used for calls to MutateRows. */
    public BigtableBulkReadRowsCallSettings.Builder bulkReadRowsSettings() {
      return bulkReadRowsSettings;
    }

    /** Returns the builder for the settings used for calls to CheckAndMutateRow. */
    public UnaryCallSettings.Builder<ConditionalRowMutation, Boolean> checkAndMutateRowSettings() {
      return checkAndMutateRowSettings;
    }

    /** Returns the builder with the settings used for calls to ReadModifyWriteRow. */
    public UnaryCallSettings.Builder<ReadModifyWriteRow, Row> readModifyWriteRowSettings() {
      return readModifyWriteRowSettings;
    }

    @SuppressWarnings("unchecked")
    public EnhancedBigtableStubSettings build() {
      Preconditions.checkState(projectId != null, "Project id must be set");
      Preconditions.checkState(instanceId != null, "Instance id must be set");

      if (isRefreshingChannel) {
        Preconditions.checkArgument(
            getTransportChannelProvider() instanceof InstantiatingGrpcChannelProvider,
            "refreshingChannel only works with InstantiatingGrpcChannelProviders");
        InstantiatingGrpcChannelProvider.Builder channelProviderBuilder =
            ((InstantiatingGrpcChannelProvider) getTransportChannelProvider()).toBuilder();
        Credentials credentials = null;
        if (getCredentialsProvider() != null) {
          try {
            credentials = getCredentialsProvider().getCredentials();
          } catch (IOException e) {
            throw new RuntimeException(e);
          }
        }
        // Use shared credentials
        this.setCredentialsProvider(FixedCredentialsProvider.create(credentials));
        channelProviderBuilder.setChannelPrimer(
            BigtableChannelPrimer.create(
                credentials, projectId, instanceId, appProfileId, primedTableIds));
        this.setTransportChannelProvider(channelProviderBuilder.build());
      }
      return new EnhancedBigtableStubSettings(this);
    }
    // </editor-fold>
  }

  @Override
  public String toString() {
    return MoreObjects.toStringHelper(this)
        .add("projectId", projectId)
        .add("instanceId", instanceId)
        .add("appProfileId", appProfileId)
        .add("isRefreshingChannel", isRefreshingChannel)
        .add("primedTableIds", primedTableIds)
        .add("headerTracer", headerTracer)
        .add("readRowsSettings", readRowsSettings)
        .add("readRowSettings", readRowSettings)
        .add("sampleRowKeysSettings", sampleRowKeysSettings)
        .add("mutateRowSettings", mutateRowSettings)
        .add("bulkMutateRowsSettings", bulkMutateRowsSettings)
        .add("bulkReadRowsSettings", bulkReadRowsSettings)
        .add("checkAndMutateRowSettings", checkAndMutateRowSettings)
        .add("readModifyWriteRowSettings", readModifyWriteRowSettings)
        .add("parent", super.toString())
        .toString();
  }
}