Confirm whether the consumer group has a message backlog. If no backlog exists, empty messages will be returned after the fetch.max.wait time. This parameter is configured on the consumer client, with a default value of 500ms. Configuration item:
# Fetch request waiting time.
fetch.max.wait.ms=500
Solutions
If a message backlog exists but the messages pulled are empty, it is recommended to check the version of the client SDK. If the SDK version is outdated, it is recommended to upgrade the SDK version. See SDK Reference.
