Pub/Sub topic properties are the characteristics of a topic. You can set topic properties when you create or update a topic.
This document describes the different topic properties you can set for a topic.
Before you begin
- Learn about topics and the publish messages workflow.
- Create a topic.
Common topic properties
When you create a topic, you must specify a number of options to set up the topic. Some of these properties are common to all types of topics and are discussed in the next sections.
Add a default subscription
Adds a default subscription to the Pub/Sub topic. You can create another subscription for the topic after the topic is created. The default subscription has the following properties:
- Subscription ID of
-sub - Pull delivery type
- Message retention duration of seven days
- Expiration after 31 days of inactivity
- Acknowledgment deadline of 10 seconds
- Immediate retry policy
Schema
A schema is a format that the message data field must follow. A schema is a contract between the publisher and subscriber that Pub/Sub enforces.