QoS

The quality of service (QoS) levels for MigratoryData messaging.

Public Attributes

	Name
	STANDARD The `[QoS.STANDARD]()` should be used for noncritical messages which will not be included in the cache of the MigratoryData cluster.
	GUARANTEED The `[QoS.GUARANTEED]()` should be used for critical messages which will be included in the cache of the MigratoryData cluster.

Public Attributes Documentation

variable STANDARD

STANDARD;

The [QoS.STANDARD]() should be used for noncritical messages which will not be included in the cache of the MigratoryData cluster.

In this way, after a connection recovery, a client will not receive as part of the recovery process the messages with [QoS.STANDARD](/docs/client-api/php/classes/interfaceqos/#variable-standard).

Note: This QoS level corresponds to the at-most-once delivery semantics.

variable GUARANTEED

GUARANTEED;

The [QoS.GUARANTEED]() should be used for critical messages which will be included in the cache of the MigratoryData cluster.

In this way, after a connection recovery, a client will receive as part of the recovery process the messages with [QoS.GUARANTEED](/docs/client-api/php/classes/interfaceqos/#variable-guaranteed).

Note: This QoS level corresponds to the at-least-once delivery semantics. Also, it might correspond to the exactly-once delivery semantics provided that subscribers are responsible for filtering out duplicate receptions, if it at all matters for the application. Typically, a small buffer containing the identifiers of recently-received messages is sufficient for this task.