This topic describes messages that are published to Message Service (MNS) topics. You can specify Message, MessageTag and other parameters when publishing messages. The maximum retention period of messages in topics is one day. After the specified retention period, messages are collected by garbage collector no matter whether messages have been pushed to subscribers.


  • The ID of the message.
  • Each message in a topic has a unique message ID.
The message content.
The MD5 hash of the message content.
  • The tag of the message.
  • If you specify a message tag when publishing messages, MNS push messages to subscribers based on the tag.
The time when the message was published. This value is a UNIX timestamp representing the number of milliseconds that have elapsed since the epoch time January 1, 1970, 00:00:00 UTC.