Create and manage Lite topics

This document explains how to create, view, and delete a Pub/Sub Lite topic.

Overview of a Lite topic

A Pub/Sub Lite service requires a topic to which publishers can send messages so that subscribers can receive those messages. Within Pub/Sub Lite, you can choose to create a zonal or regional Lite topic.

A zonal Lite and a regional Lite topic differ only in the way they replicate data. All other topic properties are the same as described in a later section of this document.

Data replication in a Lite topic

Pub/Sub Lite replicates data asynchronously.

The following list describes the data replication process for different types of Pub/Sub Lite topics:

  • Pub/Sub Lite regional topics store data in two zones. Replication between the two zones is asynchronous. Pub/Sub Lite replication is within just one region.

  • Pub/Sub Lite zonal topics replicate data within just one zone.

The availability of Pub/Sub Lite depends on the availability of its underlying components, which include both the application frontend and storage.

The availability of a Pub/Sub Lite zonal topic depends on the availability of both the application frontend and storage in its configured zone. If the application frontend or storage experiences a zonal failure, the zonal Lite topic becomes unavailable for the duration of the outage.

The availability of a Pub/Sub Lite regional topic depends on the availability of the application frontend and storage in its configured region. The following types of failure are possible:

  • If the application frontend or storage experiences a zonal failure, the regional Lite topic remains available.

  • If both the application frontend and storage experience a zonal failure, the regional Lite topic remains available as long as both the components don't start failing at the same time.

  • If both the application frontend and storage fail simultaneously, the regional Lite topic remains unavailable for the duration of the outage. During this time, clients may fail to publish or consume messages, but messages are still delivered in the right order.

A regional Lite topic provides protection from most types of single-zone failures. However in some rare cases, the asynchronous nature of replication may cause a simultaneous failure of multiple components in a single zone. As a result, a regional Lite topic becomes unavailable.

Properties of a Lite topic

Lite topics have the following properties:

  • Number of partitions. A partition is the basic unit of parallelism in Pub/Sub Lite. A Lite topic can have one or more partitions.

  • Capacity of a partition. The capacity of a partition is described by the following three properties:

    • Publish throughput (MiBps). The maximum rate at which you can publish messages.

    • Subscribe throughput (MiBps). The maximum rate at which messages are forwarded to Lite subscriptions.

    • Storage (GiB). The maximum size of the messages in the partition. The minimum configurable capacity of a partition is 30 GiB.

  • Storage capacity of a Lite topic. All the partitions in a Lite topic have the same configured storage capacity. The total storage capacity of a Lite topic is the sum of the storage capacity of all the partitions in the topic. For example, if a Lite topic has 8 partitions and each partition is of size 30 GiB, the total storage capacity of the Lite topic is 240 GiB (8 x 30).

  • Throughput capacity of a Lite topic. Throughput capacity consists of the total publish and subscribe throughput capacity of all the partitions in the Lite topic. Even if you have a topic that, in aggregate, can support 1 GiBps of publish throughput, it is the per-partition publish limit that effectively limits throughput.

  • Limit of subscriber client and subscriptions. Pub/Sub Lite supports a single subscriber client for a single partition and a single subscription. For example, a subscription to a topic with 5 partitions can have, at most, 5 subscriber clients that consume messages from it. If more subscriber clients are configured, the excess clients remain idle. The same topic with 2 subscriptions can have up to 10 subscriber clients, 5 clients for each subscription.

  • Reservations. A reservation is the easiest way to provision and manage throughput capacity for a number of topics. Provisioning throughput capacity with reservations is required for regional Lite and is optional for zonal Lite topics.

    If you do not use reservations for a zonal Lite topic, you must explicitly provision the publish and subscribe throughput capacity of the topic. Without a reservation, all the partitions in a Lite topic have the same configured throughput capacity. To know more, see Configure throughput capacity without reservations.

  • Storage configuration. To configure storage, you must specify both the storage capacity and optionally, the message retention period.

    • Message retention period. The maximum amount of time for which a Lite topic stores messages. If you don't specify a message retention period, the Lite topic stores messages until you exceed the storage capacity.

    • Storage capacity. The Pub/Sub Lite topic capacity is determined by the number of partitions in the topic and the storage capacity of each partition. Storage per partition is the amount of storage, in bytes, for each partition. Note that regional Lite topics use two bytes of storage capacity for each byte published. Zonal Lite topics use one byte of storage capacity for each byte published.

    If you exceed the storage capacity, the Pub/Sub Lite service continues to publish messages. However, in order to create more storage capacity, the oldest message from the partition are deleted. The deletion of the oldest messages occurs even if the messages are within the message retention period. The service never deletes messages before their TTL expires, unless their removal is necessary to make space for newly published messages. For information about how capacity relates to pricing, see Pub/Sub Lite pricing.

Increase throughput capacity of a Lite topic

If you do not use Lite reservations, you can set the throughput capacity of each partition of any zonal Lite topic to a value set by the following limits:

  • Publish throughput between 4 and 16 MiBps

  • Subscribe throughput between 4 and 32 MiBps

With reservations, each partition can consume any throughput capacity within the limits described in the preceding section, as long as the total capacity of the reservation is not exceeded. Optionally, you can set a lower limit on the actual throughput per partition to make your traffic more predictable.

You can increase the number of partitions in a topic to scale it horizontally. The number of partitions in a topic cannot be decreased.

When you change the number of partitions, the relative order of messages is not preserved. Internally, messages are assigned to partitions using a hash function. Updating the number of partitions in a topic changes this hash function. Messages with the same key published after the partition count update are likely to be mapped to a different partition than those published before the update.

Additionally, the topic resize takes a few seconds to propagate to all the publishers. There is a short time when some publishers use the new hash function and some are still use the old one.

Increase storage capacity of a Lite topic

You can increase or decrease the amount of storage in a Lite topic. The Lite topic provisions the same amount of storage to each partition. If you increase the storage to 60 GiB, each of the partitions gets 60 GiB of storage.

If you decrease the amount of storage in a Lite topic, the Pub/Sub Lite service removes the oldest messages first.

For information about how capacity relates to pricing, see Pub/Sub Lite pricing

Create a Lite topic

You can create Lite topics with the Google Cloud console, the Google Cloud CLI, or the Pub/Sub Lite API.

For a list of the available regions and zones, see Pub/Sub Lite locations.

Console

  1. Go to the Lite Topics page.

    Go to Lite Topics

  2. Click Create Lite topic.

    1. To create a zonal Lite topic, select a region and a zone within the region.

    2. To create a regional Lite topic, select a region.

    You cannot update the location after a topic is created.

  3. In the Name section, enter a Lite topic ID.

    The Lite topic name includes the Lite topic ID, the location, and the project number.

  4. In the Throughput section:

    1. Select or create a reservation.

      This is optional for a zonal Lite topic and required for a regional Lite topic.

    2. Enter the peak publish throughput and the peak subscribe throughput.

      A number of partitions are set automatically based on your inputs. You can edit this number after you save the topic.

  5. In the Message storage section:

    1. Enter the storage per partition.

    2. Select one of the two options for the message retention period.

  6. Review the changes and click Create.

gcloud

To create a Lite topic, use the gcloud pubsub lite-topics create command:

gcloud pubsub lite-topics create TOPIC_ID \
  --location=LOCATION \
  --partitions=NUMBER_OF_PARTITIONS \
  --per-partition-bytes=STORAGE_PER_PARTITION \
  [--throughput-reservation=RESERVATION_NAME \]
  [--message-retention-period=MESSAGE_RETENTION_PERIOD]

Replace the following:

  • TOPIC_ID: the ID of the Lite topic

  • LOCATION: the name of a location that Pub/Sub Lite supports

  • NUMBER_OF_PARTITIONS: an integer for the number of partitions in the Lite topic

  • STORAGE_PER_PARTITION: the amount of storage for each partition, such as 30GiB

  • RESERVATION_NAME: the fully qualified path of a Lite reservation such as projects/123456789/locations/us-west1/reservations/my-reservation

  • MESSAGE_RETENTION_PERIOD: the amount of time the Lite topic stores messages, such as 1d or 2w

If the request is successful, the command line displays a confirmation:

Created [TOPIC_ID].

Protocol

To create a Lite topic, send a POST request like the following:

POST https://REGION-pubsublite.googleapis.com/v1/admin/projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
Authorization: Bearer $(gcloud auth print-access-token)

Replace the following:

Specify the following fields in the request body:

{
  "partitionConfig": {
       "count": NUMBER_OF_PARTITIONS,
       "capacity": {
         "publishMibPerSec": publish_CAPACITY,
         "subscribeMibPerSec": subscribe_CAPACITY,
       }
  },
  "retentionConfig": {
       "perPartitionBytes": STORAGE_PER_PARTITION,
       "period": MESSAGE_RETENTION_PERIOD,
  },
  "reservationConfig": {
       "throughputReservation": RESERVATION_NAME
  }
}

Replace the following:

  • NUMBER_OF_PARTITIONS: an integer for the number of partitions in the Lite topic

  • STORAGE_PER_PARTITION: the amount of storage for each partition, such as 30GiB

  • publish_CAPACITY: an integer for the publish throughput capacity of each partition

  • subscribe_CAPACITY: an integer for the subscribe throughput capacity of each partition

  • MESSAGE_RETENTION_PERIOD: the amount of time the Lite topic stores messages, such as 1d or 2w

  • RESERVATION_NAME: the fully qualified path of a Lite reservation such as projects/123456789/locations/us-west1/reservations/my-reservation

If the request is successful, the response is the Lite topic in JSON format:

{
  "name": projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID,
  "partitionConfig": {
       "count": NUMBER_OF_PARTITIONS,
       "capacity": {
         "publishMibPerSec": publish_CAPACITY,
         "subscribeMibPerSec": subscribe_CAPACITY,
       }
  },
  "retentionConfig": {
       "perPartitionBytes": STORAGE_PER_PARTITION,
       "period": MESSAGE_RETENTION_PERIOD,
  },
  "reservationConfig": {
       "throughputReservation": RESERVATION_NAME
  }
}

Go

Before running this sample, follow the Go setup instructions in Pub/Sub Lite Client Libraries.

import (
	"context"
	"fmt"
	"io"

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

func createTopic(w io.Writer, projectID, region, location, topicID, reservation string) error {
	// projectID := "my-project-id"
	// region := "us-central1" // see https://cloud.google.com/pubsub/lite/docs/locations
	// 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: %v", err)
	}
	defer client.Close()

	const gib = 1 << 30

	topicPath := fmt.Sprintf("projects/%s/locations/%s/topics/%s", projectID, location, topicID)
	// For ranges of fields in TopicConfig, see https://pkg.go.dev/cloud.google.com/go/pubsublite/#TopicConfig
	topic, err := client.CreateTopic(ctx, pubsublite.TopicConfig{
		Name:                       topicPath,
		PartitionCount:             2, // Must be >= 1 and cannot decrease after creation.
		PublishCapacityMiBPerSec:   4,
		SubscribeCapacityMiBPerSec: 8,
		PerPartitionBytes:          30 * gib,
		RetentionDuration:          pubsublite.InfiniteRetention,
		ThroughputReservation:      reservation,
	})
	if err != nil {
		return fmt.Errorf("client.CreateTopic got err: %v", err)
	}
	fmt.Fprintf(w, "Created topic: %#v\n", topic)
	return nil
}

Java

Before running this sample, follow the Java setup instructions in Pub/Sub Lite Client Libraries.

import com.google.api.gax.rpc.AlreadyExistsException;
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.util.Durations;
import java.util.concurrent.ExecutionException;

public class CreateTopicExample {

  public static void main(String... args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String cloudRegion = "your-cloud-region";
    char zoneId = 'a';
    String topicId = "your-topic-id";
    String reservationId = "your-reservation-id";
    long projectNumber = Long.parseLong("123456789");
    int partitions = 1;
    // True if using a regional location. False if using a zonal location.
    // https://cloud.google.com/pubsub/lite/docs/topics
    boolean regional = false;

    createTopicExample(
        cloudRegion, zoneId, projectNumber, topicId, reservationId, partitions, regional);
  }

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

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

    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();

    Topic topic =
        Topic.newBuilder()
            .setPartitionConfig(
                PartitionConfig.newBuilder()
                    // Set throughput capacity per partition in MiB/s.
                    .setCapacity(
                        Capacity.newBuilder()
                            // Must be 4-16 MiB/s.
                            .setPublishMibPerSec(4)
                            // Must be 4-32 MiB/s.
                            .setSubscribeMibPerSec(8)
                            .build())
                    .setCount(partitions))
            .setRetentionConfig(
                RetentionConfig.newBuilder()
                    // How long messages are retained.
                    .setPeriod(Durations.fromDays(1))
                    // Set storage per partition to 30 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`.
                    .setPerPartitionBytes(30 * 1024 * 1024 * 1024L))
            .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 response = adminClient.createTopic(topic).get();
      if (regional) {
        System.out.println(response.getAllFields() + " (regional topic) created successfully.");
      } else {
        System.out.println(response.getAllFields() + " (zonal topic) created successfully.");
      }
    } catch (ExecutionException e) {
      try {
        throw e.getCause();
      } catch (AlreadyExistsException alreadyExists) {
        System.out.println("This topic already exists.");
      } catch (Throwable throwable) {
        throwable.printStackTrace();
      }
    }
  }
}

Python

Before running this sample, follow the Python setup instructions in Pub/Sub Lite Client Libraries.

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

# TODO(developer):
# project_number = 1122334455
# cloud_region = "us-central1"
# zone_id = "a"
# topic_id = "your-topic-id"
# reservation_id = "your-reservation-id"
# num_partitions = 1
# regional = True

cloud_region = CloudRegion(cloud_region)
reservation_path = ReservationPath(project_number, cloud_region, reservation_id)

topic_path = None
if regional:
    #  A regional topic.
    topic_path = TopicPath(project_number, cloud_region, topic_id)
else:
    #  A zonal topic
    topic_path = TopicPath(
        project_number, CloudZone(cloud_region, zone_id), topic_id
    )

topic = Topic(
    name=str(topic_path),
    partition_config=Topic.PartitionConfig(
        # A topic must have at least one partition.
        count=num_partitions,
        # Set throughput capacity per partition in MiB/s.
        capacity=Topic.PartitionConfig.Capacity(
            # Set publish throughput capacity per partition to 4 MiB/s. Must be >= 4 and <= 16.
            publish_mib_per_sec=4,
            # Set subscribe throughput capacity per partition to 4 MiB/s. Must be >= 4 and <= 32.
            subscribe_mib_per_sec=8,
        ),
    ),
    retention_config=Topic.RetentionConfig(
        # Set storage per partition to 30 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`.
        per_partition_bytes=30 * 1024 * 1024 * 1024,
        # Allow messages to be retained for 7 days.
        period=Duration(seconds=60 * 60 * 24 * 7),
    ),
    reservation_config=Topic.ReservationConfig(
        throughput_reservation=str(reservation_path),
    ),
)

client = AdminClient(cloud_region)
try:
    response = client.create_topic(topic)
    if regional:
        print(f"{response.name} (regional topic) created successfully.")
    else:
        print(f"{response.name} (zonal topic) created successfully.")
except AlreadyExists:
    print(f"{topic_path} already exists.")

After creating the Lite topic, you can scale the per-partition throughput and storage capacity. You can also increase, but not decrease the number of partitions.

Update a Lite topic

You can update the following properties of a Lite topic:

  • The reservation associated with the Lite topic

  • The number of partitions in the topic (can only be increased)

  • The publish and subscribe throughput capacity limits

  • The storage per partition

  • The type of message retention

Before you scale either the throughput capacity or the storage capacity of a topic, refer to Scale throughput capacity and Scale storage capacity.

You can update a Lite topic with the Google Cloud console, the Google Cloud CLI, or the Pub/Sub Lite API.

Console

  1. Go to the Lite Topics page.

    Go to Lite Topics

  2. Click the Lite topic ID.

  3. Click Edit.

  4. You can make any or all the following updates:

    • Use a different reservation. For zonal topics, you can opt to not use a reservation.
    • Enter the number of partitions. This value can be increased but not decreased.
    • Enable or disable the maximum allowed publish and subscribe throughput.
    • For zonal topics, update the reserved publish and subscribe throughput. For topics with a reservation attached, the updated throughput reflects the new maximum limit.
    • Edit the storage capacity per partition.
    • Edit the message retention period.
  5. Click Update.

gcloud

To update a Lite topic, use the gcloud pubsub lite-topics update command:

gcloud pubsub lite-topics update TOPIC_ID \
  --location=LOCATION \
  --partitions=NUMBER_OF_PARTITIONS \
  --per-partition-publish-mib=publish_CAPACITY \
  --per-partition-subscribe-mib=subscribe_CAPACITY \
  --per-partition-bytes=STORAGE_PER_PARTITION \
  --message-retention-period=MESSAGE_RETENTION_PERIOD

Replace the following:

  • TOPIC_ID: the ID of the Lite topic

  • LOCATION: the name of the location that the Lite topic is in

  • NUMBER_OF_PARTITIONS: the number of partitions to configure for the Lite topic.

  • publish_CAPACITY: an integer for the publish throughput capacity of each partition

  • subscribe_CAPACITY: an integer for the subscribe throughput capacity of each partition

  • STORAGE_PER_PARTITION: the amount of storage for each partition, such as 30GiB

  • MESSAGE_RETENTION_PERIOD: the amount of time the Lite topic stores messages, such as 1d or 2w

If the request is successful, the command line displays the Lite topic:

name: projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
partitionConfig:
  count: NUMBER_OF_PARTITIONS
  capacity:
    publishMibPerSec: publish_CAPACITY
    subscribeMibPerSec: subscribe_CAPACITY
retentionConfig:
  perPartitionBytes: STORAGE_PER_PARTITION
  period: MESSAGE_RETENTION_PERIOD

Protocol

To update a Lite topic, send a PATCH request like the following:

PATCH https://REGION-pubsublite.googleapis.com/v1/admin/projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID?updateMask=partitionConfig.capacity,retentionConfig.perPartitionBytes,retentionConfig.period,partitionConfig.count
Authorization: Bearer $(gcloud auth print-access-token)

Replace the following:

  • REGION: the region that the Lite topic is in

  • PROJECT_NUMBER: the project number of the project with the Lite topic

  • LOCATION: the name of the location that the Lite topic is in

  • TOPIC_ID: the ID of the Lite topic

Specify the following fields in the request body:

{
  "partitionConfig": {
      "count": NUMBER_OF_PARTITIONS,
      "capacity": {
         "publishMibPerSec": publish_CAPACITY,
         "subscribeMibPerSec": subscribe_CAPACITY,
      }
   },
   "retentionConfig": {
       "perPartitionBytes": STORAGE_PER_PARTITION,
       "period": MESSAGE_RETENTION_PERIOD,
   },
}

Replace the following:

  • publish_CAPACITY: an integer for the publish throughput capacity of each partition

  • subscribe_CAPACITY: an integer for the subscribe throughput capacity of each partition

  • STORAGE_PER_PARTITION: the amount of storage for each partition, such as 30GiB

  • MESSAGE_RETENTION_PERIOD: the amount of time the Lite topic stores messages, such as 1d or 2w

  • NUMBER_OF_PARTITIONS: the number of partitions to configure for the Lite topic.

If the request is successful, the response is the Lite topic in JSON format:

{
  "name": projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID,
  "partitionConfig": {
      "count": NUMBER_OF_PARTITIONS,
      "capacity": {
         "publishMibPerSec": publish_CAPACITY,
         "subscribeMibPerSec": subscribe_CAPACITY,
      }
   },
   "retentionConfig": {
       "perPartitionBytes": STORAGE_PER_PARTITION,
       "period": MESSAGE_RETENTION_PERIOD,
   },
}

Go

Before running this sample, follow the Go setup instructions in Pub/Sub Lite Client Libraries.

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: %v", 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: %v", err)
	}
	fmt.Fprintf(w, "Updated topic: %v\n", updatedCfg)
	return nil
}

Java

Before running this sample, follow the Java setup instructions in Pub/Sub Lite Client Libraries.

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

Before running this sample, follow the Python setup instructions in Pub/Sub Lite Client Libraries.

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.")

View Lite topic details

You can get details about a Lite topic using the Google Cloud console, the Google Cloud CLI, or the Pub/Sub Lite API.

Console

  1. Go to the Lite Topics page.

    Go to Lite Topics

  2. Click the Lite topic ID.

gcloud

To get details about a Lite topic, use the gcloud pubsub lite-topics describe command:

gcloud pubsub lite-topics describe TOPIC_ID \
--location=LOCATION

Replace the following:

  • TOPIC_ID: the ID of the Lite topic

  • LOCATION: the name of the location that the Lite topic is in

If the request is successful, the command line displays the Lite topic:

name: projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
partitionConfig:
  count: NUMBER_OF_PARTITIONS
  capacity:
    publishMibPerSec: publish_CAPACITY
    subscribeMibPerSec: subscribe_CAPACITY
retentionConfig:
  perPartitionBytes: STORAGE_PER_PARTITION
  period: MESSAGE_RETENTION_PERIOD

Protocol

To get details about a Lite topic, send a GET request like the following:

GET https://REGION-pubsublite.googleapis.com/v1/admin/projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
Authorization: Bearer $(gcloud auth print-access-token)

Replace the following:

  • REGION: the region that the Lite topic is in

  • PROJECT_NUMBER: the project number of the project with the Lite topic

  • LOCATION: the name of the location that the Lite topic is in

  • TOPIC_ID: the ID of the Lite topic

If the request is successful, the response is the Lite topic in JSON format:

{
  "name": projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID,
  "partitionConfig": {
      "count": NUMBER_OF_PARTITIONS,
      "capacity": {
         "publishMibPerSec": publish_CAPACITY,
         "subscribeMibPerSec": subscribe_CAPACITY,
      }
   },
   "retentionConfig": {
       "perPartitionBytes": STORAGE_PER_PARTITION,
       "period": MESSAGE_RETENTION_PERIOD,
   },
}

Go

Before running this sample, follow the Go setup instructions in Pub/Sub Lite Client Libraries.

import (
	"context"
	"fmt"
	"io"

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

func getTopic(w io.Writer, projectID, region, location, topicID 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"
	ctx := context.Background()
	client, err := pubsublite.NewAdminClient(ctx, region)
	if err != nil {
		return fmt.Errorf("pubsublite.NewAdminClient: %v", err)
	}
	defer client.Close()

	topicPath := fmt.Sprintf("projects/%s/locations/%s/topics/%s", projectID, location, topicID)
	topic, err := client.Topic(ctx, topicPath)
	if err != nil {
		return fmt.Errorf("client.Topic got err: %v", err)
	}
	fmt.Fprintf(w, "Got topic: %#v\n", *topic)
	return nil
}

Java

Before running this sample, follow the Java setup instructions in Pub/Sub Lite Client Libraries.

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.TopicName;
import com.google.cloud.pubsublite.TopicPath;
import com.google.cloud.pubsublite.proto.Topic;
import java.util.concurrent.ExecutionException;

public class GetTopicExample {

  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';
    // Choose an existing topic.
    String topicId = "your-topic-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;

    getTopicExample(cloudRegion, zoneId, projectNumber, topicId, regional);
  }

  public static void getTopicExample(
      String cloudRegion, char zoneId, long projectNumber, String topicId, 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();

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

    try (AdminClient adminClient = AdminClient.create(adminClientSettings)) {
      Topic topic = adminClient.getTopic(topicPath).get();
      long numPartitions = adminClient.getTopicPartitionCount(topicPath).get();
      System.out.println(topic.getAllFields() + "\nhas " + numPartitions + " partition(s).");
    } catch (ExecutionException e) {
      try {
        throw e.getCause();
      } catch (NotFoundException notFound) {
        System.out.println("This topic is not found.");
      } catch (Throwable throwable) {
        throwable.printStackTrace();
      }
    }
  }
}

Python

Before running this sample, follow the Python setup instructions in Pub/Sub Lite Client Libraries.

from google.api_core.exceptions import NotFound
from google.cloud.pubsublite import AdminClient
from google.cloud.pubsublite.types import CloudRegion, CloudZone, TopicPath

# TODO(developer):
# project_number = 1122334455
# cloud_region = "us-central1"
# zone_id = "a"
# topic_id = "your-topic-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)

client = AdminClient(cloud_region)
try:
    response = client.get_topic(topic_path)
    num_partitions = client.get_topic_partition_count(topic_path)
    print(f"{response.name} has {num_partitions} partition(s).")
except NotFound:
    print(f"{topic_path} not found.")

List Lite topics

You can list Lite topics in a project using the Google Cloud console, the Google Cloud CLI, or the Pub/Sub Lite API.

Console

  • To view a list of the Lite topics in a project, go to the Lite Topics page.

    Go to Lite Topics

gcloud

gcloud pubsub lite-topics list \
  --location=LOCATION

Replace LOCATION with the name of the location that the Lite topic is in.

If the request is successful, the command line displays the Lite topics:

---
name: projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
partitionConfig:
  count: NUMBER_OF_PARTITIONS
  capacity:
    publishMibPerSec: publish_CAPACITY
    subscribeMibPerSec: subscribe_CAPACITY
retentionConfig:
  perPartitionBytes: STORAGE_PER_PARTITION
  period: MESSAGE_RETENTION_PERIOND
---
name: projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
partitionConfig:
  count: NUMBER_OF_PARTITIONS
  capacity:
    publishMibPerSec: publish_CAPACITY
    subscribeMibPerSec: subscribe_CAPACITY
retentionConfig:
  perPartitionBytes: STORAGE_PER_PARTITION
  period: MESSAGE_RETENTION_PERIOND

Protocol

To list the Lite topics in a project, send a GET request like the following:

GET https://REGION-pubsublite.googleapis.com/v1/admin/projects/PROJECT_NUMBER/topics
Authorization: Bearer $(gcloud auth print-access-token)

Replace the following:

  • REGION: the region that the Lite topic is in

  • PROJECT_NUMBER: the project number of the project with the Lite topic

If the request is successful, the response is a list of Lite topics in JSON format:

{
  "topics": [
      {
          "name": "projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID",
      },
      {
          "name": "projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID",
      }
  ]
}

Go

Before running this sample, follow the Go setup instructions in Pub/Sub Lite Client Libraries.

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/pubsublite"
	"google.golang.org/api/iterator"
)

func listTopics(w io.Writer, projectID, region, zone string) error {
	// projectID := "my-project-id"
	// region := "us-central1"
	// zone := "us-central1-a"
	ctx := context.Background()
	client, err := pubsublite.NewAdminClient(ctx, region)
	if err != nil {
		return fmt.Errorf("pubsublite.NewAdminClient: %v", err)
	}
	defer client.Close()

	parent := fmt.Sprintf("projects/%s/locations/%s", projectID, zone)
	topicIter := client.Topics(ctx, parent)
	for {
		topic, err := topicIter.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return fmt.Errorf("topicIter.Next got err: %v", err)
		}
		fmt.Fprintf(w, "Got topic: %#v\n", topic)
	}
	return nil
}

Java

Before running this sample, follow the Java setup instructions in Pub/Sub Lite Client Libraries.

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.LocationPath;
import com.google.cloud.pubsublite.ProjectNumber;
import com.google.cloud.pubsublite.proto.Topic;
import java.util.List;

public class ListTopicsExample {

  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';
    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;

    listTopicsExample(cloudRegion, zoneId, projectNumber, regional);
  }

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

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

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

    LocationPath locationPath =
        LocationPath.newBuilder()
            .setProject(ProjectNumber.of(projectNumber))
            .setLocation(location)
            .build();

    try (AdminClient adminClient = AdminClient.create(adminClientSettings)) {
      List<Topic> topics = adminClient.listTopics(locationPath).get();
      for (Topic topic : topics) {
        System.out.println(topic.getAllFields());
      }
      System.out.println(topics.size() + " topic(s) listed.");
    }
  }
}

Python

Before running this sample, follow the Python setup instructions in Pub/Sub Lite Client Libraries.

from google.cloud.pubsublite import AdminClient
from google.cloud.pubsublite.types import CloudRegion, CloudZone, LocationPath

# TODO(developer):
# project_number = 1122334455
# cloud_region = "us-central1"
# zone_id = "a"
# regional = True

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

location_path = LocationPath(project_number, location)

client = AdminClient(cloud_region)
response = client.list_topics(location_path)

for topic in response:
    print(topic)

print(f"{len(response)} topic(s) listed in your project and location.")

Delete a Lite topic

You can delete Lite topics with the Google Cloud console, the Google Cloud CLI, or the Pub/Sub Lite API.

Console

  1. Go to the Lite Topics page.

    Go to Lite Topics

  2. Click the Lite topic ID.

  3. In the Lite topic details page, click Delete.

  4. In the field that appears, enter delete to confirm that you want to delete the Lite topic.

  5. Click Delete.

gcloud

To delete a Lite topic, use the gcloud pubsub lite-topics delete command:

  1. Run the delete command:

    gcloud pubsub lite-topics delete TOPIC_ID \
     --location=LOCATION
    

    Replace the following:

    • TOPIC_ID: the ID of the Lite topic

    • LOCATION: the name of the location that the Lite topic is in

  2. To confirm, type Y.

If the request is successful, the response is the following:

Deleted topic [TOPIC_ID].

Protocol

To delete a Lite topic, send a DELETE request like the following:

DELETE https://REGION-pubsublite.googleapis.com/v1/admin/projects/PROJECT_NUMBER/locations/LOCATION/topics/TOPIC_ID
Authorization: Bearer $(gcloud auth print-access-token)

Replace the following:

  • REGION: the region that the Lite topic is in

  • PROJECT_NUMBER: the project number of the project with the Lite topic

  • LOCATION: the name of the location that the Lite topic is in

  • TOPIC_ID: the ID of the Lite topic

If the request is successful, the response is an empty JSON object.

Go

Before running this sample, follow the Go setup instructions in Pub/Sub Lite Client Libraries.

import (
	"context"
	"fmt"
	"io"

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

func deleteTopic(w io.Writer, projectID, region, location, topicID 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"
	ctx := context.Background()
	client, err := pubsublite.NewAdminClient(ctx, region)
	if err != nil {
		return fmt.Errorf("pubsublite.NewAdminClient: %v", err)
	}
	defer client.Close()

	topicPath := fmt.Sprintf("projects/%s/locations/%s/topics/%s", projectID, location, topicID)
	err = client.DeleteTopic(ctx, topicPath)
	if err != nil {
		return fmt.Errorf("client.DeleteTopic got err: %v", err)
	}
	fmt.Fprint(w, "Deleted topic\n")
	return nil
}

Java

Before running this sample, follow the Java setup instructions in Pub/Sub Lite Client Libraries.

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.TopicName;
import com.google.cloud.pubsublite.TopicPath;
import java.util.concurrent.ExecutionException;

public class DeleteTopicExample {

  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';
    // Choose an existing topic.
    String topicId = "your-topic-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 = false;

    deleteTopicExample(cloudRegion, zoneId, projectNumber, topicId, regional);
  }

  public static void deleteTopicExample(
      String cloudRegion, char zoneId, long projectNumber, String topicId, 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();

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

    try (AdminClient adminClient = AdminClient.create(adminClientSettings)) {
      adminClient.deleteTopic(topicPath).get();
      if (regional) {
        System.out.println(topicPath.toString() + " (regional topic) deleted successfully.");
      } else {
        System.out.println(topicPath.toString() + " (zonal topic) deleted successfully.");
      }
    } catch (ExecutionException e) {
      try {
        throw e.getCause();
      } catch (NotFoundException notFound) {
        System.out.println("This topic is not found.");
      } catch (Throwable throwable) {
        throwable.printStackTrace();
      }
    }
  }

Python

Before running this sample, follow the Python setup instructions in Pub/Sub Lite Client Libraries.

from google.api_core.exceptions import NotFound
from google.cloud.pubsublite import AdminClient
from google.cloud.pubsublite.types import CloudRegion, CloudZone, TopicPath

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

cloud_region = CloudRegion(cloud_region)
topic_path = None
if regional:
    #  A regional topic.
    topic_path = TopicPath(project_number, cloud_region, topic_id)
else:
    #  A zonal topic
    topic_path = TopicPath(
        project_number, CloudZone(cloud_region, zone_id), topic_id
    )

client = AdminClient(cloud_region)
try:
    client.delete_topic(topic_path)
    if regional:
        print(f"{topic_path} (regional topic) deleted successfully.")
    else:
        print(f"{topic_path} (zonal topic) deleted successfully.")
except NotFound:
    print(f"{topic_path} not found.")

If you delete a Lite topic, you can't publish messages to it. The Lite subscriptions to the Lite topic still exist, but you can't receive messages from the Lite subscriptions.

What's Next