flush command

Sends a command to AMPS that returns an acknowledgment when all previous commands from this client have been processed. This command helps applications that use AMPS determine when AMPS has received all of the messages that have been sent, making it safe for the client to exit.

tip

Notice that the publishFlush command available in the AMPS client libraries includes additional logic (when a PublishStore is present) to ensure that messages published to AMPS have been safely persisted.

Header Fields

The following table contains the header fields available to a flush command.

Field	Description
cmd	The command to be executed. Value: flush
client_name	A string identifier used to give a client a unique ID.
ack_type	Acknowledgment type for the given command. Value is a comma separated list of one or more of the following: none, completed or processed.

Returns

A flush message specifying an AckType of completed or processed will receive an ack message when all previous messages from this client have been processed by AMPS.

The following table contains the acknowledgment messages that can be returned by a flush command.

Acknowledgment	Description
none	No ack message is returned. This is the default behavior.
completed	All previous commands have been processed by AMPS.
persisted	All previous commands from this publisher have been persisted by AMPS (or have failed and produced the requested acknowledgments).
processed	AMPS has processed the flush message.
received	The flush command has been received.
stats	Not supported at this time.