The subscription relationships of a topic display the subscription status of all current consumers, including the consumer list, online status, and message consumption status. By viewing this information, you can confirm whether messages are consumed normally, promptly detect abnormal topics without consumer subscriptions, and assess the impact scope of business changes.
Prerequisites
You have created a corresponding namespace and topic.
You have created a message producer and consumer based on the software development kit (SDK) provided by TDMQ for Apache Pulsar, and they are running properly.
2. On the Topic list page, locate the topic you want to view, click View Subscription/Consumer in the operation column to go to the subscription list.
3. In the subscription list, the top-level list displays all subscriptions to the current topic. When expanded, you can see each subscription's consumer connection instances and the consumption progress of each shard.
Setting the Offset
1. In the subscription list, click Offset Settings in the operation column to manually set the consumption offset for each subscription based on a time dimension, which specifies the starting point from which consumers under this subscription begin consuming messages.
2. Click Save to complete the setup.
Recreating Retry and Dead Letter Queues
Since users can manually delete topics, if a user deletes the topics for retry/dead letter queues and wants the system to regenerate these two types of queues, the user can follow the operations in Recreate Retry/Dead Letter Queues in the subscription settings.
To ensure compatibility with users of legacy SDKs (where retry and dead letter SDKs use lowercase suffixes in their naming rules), two suffix rules are provided. New users are advised to adopt the Apache Pulsar SDK (uppercase suffix), for which no configuration change is required.
Deleting a Subscription
Note
After deleting a subscription under a certain topic, if that subscription is also associated with other topics (including system-created retry/dead letter queues), it will still exist under those other topics and will not be completely deleted.
1. In the subscription list, locate the subscription to be deleted, choose More > Delete in the operation column, or select multiple subscriptions and click Delete at the top of the subscription list.
2. In the pop-up dialog box, click Delete to complete the deletion.
Note:
When the forced deletion feature is enabled, a subscription can be forcibly deleted even if it has active consumer connections.
