### Motivation Right now, If Consumer does cumulative ack then Ack-Tracker continuously acking with invalid messageId and continuously sending unnecessary cmds to broker. which very first cumulative-ack, client sets `lastCumulativeAck` other than `MessageId.earliest` and because of that ack-tracker flushes ack on every timer task.
### Modifications avoid sending unnecessary ack-cmd to broker. [ Full content available at: https://github.com/apache/incubator-pulsar/pull/2498 ] This message was relayed via gitbox.apache.org for [email protected]
