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更新精简版主题

更新精简版主题的保留期限、缩放比例（吞吐量容量）和每个分区字节数（存储容量）。

深入探索

如需查看包含此代码示例的详细文档，请参阅以下内容：

创建和管理精简版主题

代码示例

Go

如需向 Pub/Sub Lite 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/pubsublite"
)

func updateTopic(w io.Writer, projectID, region, location, topicID, reservation string) error {
	// projectID := "my-project-id"
	// region := "us-central1"
	// NOTE: location can be either a region ("us-central1") or a zone ("us-central1-a")
	// For a list of valid locations, see https://cloud.google.com/pubsub/lite/docs/locations.
	// location := "us-central1"
	// topicID := "my-topic"
	// reservation := "projects/my-project-id/reservations/my-reservation"
	ctx := context.Background()
	client, err := pubsublite.NewAdminClient(ctx, region)
	if err != nil {
		return fmt.Errorf("pubsublite.NewAdminClient: %w", err)
	}
	defer client.Close()

	topicPath := fmt.Sprintf("projects/%s/locations/%s/topics/%s", projectID, location, topicID)
	// For ranges of fields in TopicConfigToUpdate, see https://pkg.go.dev/cloud.google.com/go/pubsublite/#TopicConfigToUpdate
	config := pubsublite.TopicConfigToUpdate{
		Name:                       topicPath,
		PartitionCount:             3, // Partition count cannot decrease.
		PublishCapacityMiBPerSec:   8,
		SubscribeCapacityMiBPerSec: 16,
		PerPartitionBytes:          60 * 1024 * 1024 * 1024,
		RetentionDuration:          24 * time.Hour,
		ThroughputReservation:      reservation,
	}
	updatedCfg, err := client.UpdateTopic(ctx, config)
	if err != nil {
		return fmt.Errorf("client.UpdateTopic got err: %w", err)
	}
	fmt.Fprintf(w, "Updated topic: %v\n", updatedCfg)
	return nil
}

Java

如需向 Pub/Sub Lite 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

import com.google.api.gax.rpc.NotFoundException;
import com.google.cloud.pubsublite.AdminClient;
import com.google.cloud.pubsublite.AdminClientSettings;
import com.google.cloud.pubsublite.CloudRegion;
import com.google.cloud.pubsublite.CloudRegionOrZone;
import com.google.cloud.pubsublite.CloudZone;
import com.google.cloud.pubsublite.ProjectNumber;
import com.google.cloud.pubsublite.ReservationName;
import com.google.cloud.pubsublite.ReservationPath;
import com.google.cloud.pubsublite.TopicName;
import com.google.cloud.pubsublite.TopicPath;
import com.google.cloud.pubsublite.proto.Topic;
import com.google.cloud.pubsublite.proto.Topic.PartitionConfig;
import com.google.cloud.pubsublite.proto.Topic.PartitionConfig.Capacity;
import com.google.cloud.pubsublite.proto.Topic.ReservationConfig;
import com.google.cloud.pubsublite.proto.Topic.RetentionConfig;
import com.google.protobuf.FieldMask;
import com.google.protobuf.util.Durations;
import java.util.Arrays;
import java.util.concurrent.ExecutionException;

public class UpdateTopicExample {

  public static void main(String... args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String cloudRegion = "your-cloud-region";
    char zoneId = 'b';
    String topicId = "your-topic-id";
    String reservationId = "your-reservation-id";
    long projectNumber = Long.parseLong("123456789");
    // True if using a regional location. False if using a zonal location.
    // https://cloud.google.com/pubsub/lite/docs/topics
    boolean regional = true;

    updateTopicExample(cloudRegion, zoneId, projectNumber, topicId, reservationId, regional);
  }

  public static void updateTopicExample(
      String cloudRegion,
      char zoneId,
      long projectNumber,
      String topicId,
      String reservationId,
      boolean regional)
      throws Exception {

    CloudRegionOrZone location;
    if (regional) {
      location = CloudRegionOrZone.of(CloudRegion.of(cloudRegion));
    } else {
      location = CloudRegionOrZone.of(CloudZone.of(CloudRegion.of(cloudRegion), zoneId));
    }

    TopicPath topicPath =
        TopicPath.newBuilder()
            .setProject(ProjectNumber.of(projectNumber))
            .setLocation(location)
            .setName(TopicName.of(topicId))
            .build();

    ReservationPath reservationPath =
        ReservationPath.newBuilder()
            .setProject(ProjectNumber.of(projectNumber))
            .setLocation(CloudRegion.of(cloudRegion))
            .setName(ReservationName.of(reservationId))
            .build();

    Iterable<String> iterablePaths =
        Arrays.asList(
            "partition_config.scale",
            "retention_config.per_partition_bytes",
            "retention_config.period",
            "reservation_config.throughput_reservation");

    FieldMask fieldMask = FieldMask.newBuilder().addAllPaths(iterablePaths).build();

    Topic topic =
        Topic.newBuilder()
            .setPartitionConfig(
                PartitionConfig.newBuilder()
                    .setCapacity(
                        Capacity.newBuilder()
                            .setPublishMibPerSec(16)
                            .setSubscribeMibPerSec(32)
                            .build())
                    .build())
            .setRetentionConfig(
                RetentionConfig.newBuilder()
                    // Set storage per partition to 32 GiB. This must be 30 GiB-10 TiB.
                    // If the number of bytes stored in any of the topic's partitions grows
                    // beyond this value, older messages will be dropped to make room for
                    // newer ones, regardless of the value of `period`.
                    // Be careful when decreasing storage per partition as it may cause
                    // lost messages.
                    .setPerPartitionBytes(32 * 1024 * 1024 * 1024L)
                    .setPeriod(Durations.fromDays(7)))
            .setReservationConfig(
                ReservationConfig.newBuilder()
                    .setThroughputReservation(reservationPath.toString())
                    .build())
            .setName(topicPath.toString())
            .build();

    AdminClientSettings adminClientSettings =
        AdminClientSettings.newBuilder().setRegion(CloudRegion.of(cloudRegion)).build();

    try (AdminClient adminClient = AdminClient.create(adminClientSettings)) {
      Topic topicBeforeUpdate = adminClient.getTopic(topicPath).get();
      System.out.println("Before update: " + topicBeforeUpdate.getAllFields());

      Topic topicAfterUpdate = adminClient.updateTopic(topic, fieldMask).get();
      System.out.println("After update: " + topicAfterUpdate.getAllFields());
    } catch (ExecutionException e) {
      try {
        throw e.getCause();
      } catch (NotFoundException notFound) {
        System.out.println("This topic is not found.");
      } catch (Throwable throwable) {
        throwable.printStackTrace();
      }
    }
  }
}

Python

如需向 Pub/Sub Lite 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

from google.api_core.exceptions import NotFound
from google.cloud.pubsublite import AdminClient, Topic
from google.cloud.pubsublite.types import (
    CloudRegion,
    CloudZone,
    ReservationPath,
    TopicPath,
)
from google.protobuf.duration_pb2 import Duration
from google.protobuf.field_mask_pb2 import FieldMask

# TODO(developer):
# project_number = 1122334455
# cloud_region = "us-central1"
# zone_id = "a"
# topic_id = "your-topic-id"
# reservation_id = "your-reservation-id"
# regional = True

location = None
if regional:
    #  A region.
    location = CloudRegion(cloud_region)
else:
    #  A zone.
    location = CloudZone(CloudRegion(cloud_region), zone_id)

topic_path = TopicPath(project_number, location, topic_id)
reservation_path = ReservationPath(project_number, cloud_region, reservation_id)

# Defines which topic fields to update.
field_mask = FieldMask(
    paths=[
        "partition_config.capacity",
        "retention_config.per_partition_bytes",
        "retention_config.period",
        "reservation_confing.throughput_reservation",
    ]
)

# Defines how to update the topic fields.
topic = Topic(
    name=str(topic_path),
    partition_config=Topic.PartitionConfig(
        capacity=Topic.PartitionConfig.Capacity(
            publish_mib_per_sec=16,
            subscribe_mib_per_sec=32,
        )
    ),
    retention_config=Topic.RetentionConfig(
        # Set storage per partition to 32 GiB. This must be in the range 30 GiB-10TiB.
        # If the number of byptes stored in any of the topic's partitions grows beyond
        # this value, older messages will be dropped to make room for newer ones,
        # regardless of the value of `period`.
        # Be careful when decreasing storage per partition as it may cuase lost messages.
        per_partition_bytes=32 * 1024 * 1024 * 1024,
        # Allow messages to be stored for 14 days.
        period=Duration(seconds=60 * 60 * 24 * 14),
    ),
    reservation_config=Topic.ReservationConfig(
        throughput_reservation=str(reservation_path),
    ),
)

client = AdminClient(cloud_region)
try:
    response = client.update_topic(topic, field_mask)
    print(f"{response.name} updated successfully.")
except NotFound:
    print(f"{topic_path} not found.")

后续步骤

如需搜索和过滤其他 Google Cloud 产品的代码示例，请参阅 Google Cloud 示例浏览器。