unsubscribe command

The unsubscribe command allows a client to notify AMPS that it no longer wishes to receive messages related to a previous subscription.

There are two ways that a client can unsubscribe from an existing subscription:

Adding the all keyword to the SubId header field in the unsubscribe message will unsubscribe the client from all AMPS SOW topic subscriptions.
With each subscription command issued, AMPS will return a SubId with the processed acknowledgment message. Issuing an unsubscribe command using the same SubId header field which was returned as part of the original subscribe command's processed acknowledgment message will unsubscribe a client from a single subscription.

Header Fields

Field	Description
`cmd`	Command to be executed. Value: `unsubscribe`
`sub_id`	Subscription ID entered in AMPS by the client when the original `subscription` was placed. AMPS accepts a single subscription ID or a comma-delimited list of subscription ID. The keyword `all` can also be used to unsubscribe from all current subscriptions for the client. When both `SubId` and `QueryId` are provided, AMPS removes all matching subscriptions and SOW queries. This command requires at least one of the `SubId` or `QueryId` fields to be set.
`query_id`	To cancel an in-progress SOW query, the unsubscribe command accepts the Query ID entered in AMPS by the client when the original `sow` command was placed. AMPS accepts a single query ID or a comma-delimited list of query IDs. When both `SubId` and `QueryId` are provided, AMPS removes all matching subscriptions and SOW queries. This command requires at least one of the `SubId` or `QueryId` fields to be set.
`ack_type`	Acknowledgment type for the given command. Value is a comma separated list of one or more of the following: `none`, `received` or `persisted`.
`cmd_id`	If specified within an AMPS command requesting an acknowledgment message, all requested acknowledgment messages will contain the `CommandId` in the `ack` response header.

The unsubscribe command supports the received and processed acknowledgment message types, as described in the following table.

Acknowledgment	Description
`none`	No acknowledgment message is returned. This is the default behavior.
`completed`	Not supported at this time.
`processed`	AMPS has processed the `unsubscribe` message(s).
`persisted`	Not supported at this time.
`received`	The `unsubscribe` message has been received.
`stats`	Not supported at this time.