cloud.google.com/go/pubsublite (go): Package pubsublite provides an easy way to publish and receive messages using the Pub/Sub Lite service.  Google Pub/Sub services are designed to provide reliable, many-to-many, asynchronous messaging between applications. Publisher applications can send messages to a topic and other applications can subscribe to that topic to receive the messages. By decoupling senders and receivers, Google Pub/Sub allows developers to communicate between independently written applications.  Compared to Cloud Pub/Sub, Pub/Sub Lite provides partitioned data storage with predefined throughput and storage capacity. Guidance on how to choose between Cloud Pub/Sub and Pub/Sub Lite is available at https://cloud.google.com/pubsub/docs/choosing-pubsub-or-lite.  More information about Pub/Sub Lite is available at https://cloud.google.com/pubsub/lite.  See https://pkg.go.dev/cloud.google.com/go for authentication, timeouts, connection pooling and similar aspects of this package.  Examples can be found at https://pkg.go.dev/cloud.google.com/go/pubsublite#pkg-examples and https://pkg.go.dev/cloud.google.com/go/pubsublite/pscompat#pkg-examples.  Complete sample programs can be found at https://github.com/GoogleCloudPlatform/golang-samples/tree/master/pubsublite.  The cloud.google.com/go/pubsublite/pscompat subpackage contains clients for publishing and receiving messages, which have similar interfaces to their pubsub.Topic and pubsub.Subscription counterparts in cloud.google.com/go/pubsub. The following examples demonstrate how to declare common interfaces: https://pkg.go.dev/cloud.google.com/go/pubsublite/pscompat#example-NewPublisherClient-Interface and https://pkg.go.dev/cloud.google.com/go/pubsublite/pscompat#example-NewSubscriberClient-Interface.  The following imports are required for code snippets below:  Messages are published to topics. Pub/Sub Lite topics may be created like so:  Close must be called to release resources when an AdminClient is no longer required.  See https://cloud.google.com/pubsub/lite/docs/topics for more information about how Pub/Sub Lite topics are configured.  See https://cloud.google.com/pubsub/lite/docs/locations for the list of locations where Pub/Sub Lite is available.  Pub/Sub Lite uses gRPC streams extensively for high throughput. For more differences, see https://pkg.go.dev/cloud.google.com/go/pubsublite/pscompat.  To publish messages to a topic, first create a PublisherClient:  Then call Publish:  Publish queues the message for publishing and returns immediately. When enough messages have accumulated, or enough time has elapsed, the batch of messages is sent to the Pub/Sub Lite service. Thresholds for batching can be configured in PublishSettings.  Publish returns a PublishResult, which behaves like a future; its Get method blocks until the message has been sent (or has failed to be sent) to the service:  Once you've finishing publishing all messages, call Stop to flush all messages to the service and close gRPC streams. The PublisherClient can no longer be used after it has been stopped or has terminated due to a permanent error.  PublisherClients are expected to be long-lived and used for the duration of the application, rather than for publishing small batches of messages. Stop must be called to release resources when a PublisherClient is no longer required.  See https://cloud.google.com/pubsub/lite/docs/publishing for more information about publishing.  To receive messages published to a topic, create a subscription to the topic. There may be more than one subscription per topic; each message that is published to the topic will be delivered to all of its subscriptions.  Pub/Sub Lite subscriptions may be created like so:  See https://cloud.google.com/pubsub/lite/docs/subscriptions for more information about how subscriptions are configured.  To receive messages for a subscription, first create a SubscriberClient:  Messages are then consumed from a subscription via callback. The callback may be invoked concurrently by multiple goroutines (one per partition that the subscriber client is connected to).  Receive blocks until either the context is canceled or a permanent error occurs. To terminate a call to Receive, cancel its context:  Clients must call pubsub.Message.Ack() or pubsub.Message.Nack() for every message received. Pub/Sub Lite does not have ACK deadlines. Pub/Sub Lite also does not actually have the concept of NACK. The default behavior terminates the SubscriberClient. In Pub/Sub Lite, only a single subscriber for a given subscription is connected to any partition at a time, and there is no other client that may be able to handle messages.  See https://cloud.google.com/pubsub/lite/docs/subscribing for more information about receiving messages.  Pub/Sub Lite utilizes gRPC streams extensively. gRPC allows a maximum of 100 streams per connection. Internally, the library uses a default connection pool size of 8, which supports up to 800 topic partitions. To alter the connection pool size, pass a ClientOption to pscompat.NewPublisherClient and pscompat.NewSubscriberClient:
Keywords: cloud-bigquery|cloud-datastore|cloud-pubsub|cloud-storage|go|golang|google-cloud