Yes, the value of Accumulation Amount for a topic includes the number of all tagged messages in the topic.

A message producer sends messages that contain all types of tags to the same topic. Messages are stored in a queue in the order in which the messages are received. Each message has a write offset. If an ordered message is not consumed, other ordered messages cannot be consumed. When a group starts to consume messages, the tags to which the group subscribes are specified and the group obtains a consumer offset from the broker. The broker traverses the messages in the queue from the consumer offset of the group. If the tag of a message is subscribed by the group, the message is sent to the group. Otherwise, the message is skipped.

The following figure shows the consumption mechanism. After a group starts to consume messages, the consumer offset of the group moves forward. The messages that contain Tag 2 or Tag 3 are filtered out by the broker. The messages that contain Tag 1 are sent to the group.

Accumulation Amount

After you choose Consumer Status > Accumulation Amount in the console, the value that is displayed is the total number of accumulated messages, including all tagged messages. If the consumer is not online and the producer sends messages, the number of accumulated messages may grow. This is because the number of accumulated messages is calculated by subtracting the number of processed messages from the number of sent messages.