Manual Acknowledgment

To manually acknowledge processed messages and remove the messages from the queue, applications use the sow_delete command with the bookmarks of the messages to remove. Notice that AMPS only supports using a bookmark with sow_delete when removing messages from a queue, not when removing records from a SOW.

For example, given a Message object to acknowledge and a client, the code below acknowledges the message.

const acknowledgeSingle = async (client, message) => {
  return client.execute(
    new Command('sow_delete')
        .topic(message.header.topic())
        .bookmark(message.header.bookmark());
  );
};

In the example above, the program creates a sow_delete command, specifies the topic and the bookmark, and then sends the command to the server.

While this method works, creating and sending an acknowledgment for each individual message can be inefficient if your application is processing a large volume of messages. Rather than acknowledging each message individually, your application can build a comma-delimited list of bookmarks from the processed messages and acknowledge all of the messages at the same time. In this case, it's important to be sure that the number of messages you wait for is less than the maximum backlog -- the number of messages your client can have unacknowledged at a given time. Notice that both automatic acknowledgment and the convenience method Client.ack() take the maximum backlog into account.