Subscriptions have a specific lifecycle with a set of states and related properties. Its important to understand these states as well as their transitions.

Subscriptions cannot be modified once created. In order to "change" a subscription, you must cancel the existing subscription and create a new one. Once a subscription is CANCELED it cannot return to any other state.

Once allocated, listeners will attempt to reconnect until the subscription is canceled. However state transitions only happen under certain conditions.

PENDING

When a subscription is created it is defaulted to a PENDING state. This means that a listener has not been allocated yet. In the event that a listener cannot obtained, you would not be charged while a subscription remains in this state.

CONNECTING

In this state, a listener has been allocated for your subscription and begins the connection process. The subscription will remain in this state until a successful connection has been made to the resource. This state can also be rentered in the event that the connection is dropped.

LISTENING

Once a listener has succesfully connected to the endpoint, it enters the LISTENING state. In this state the listener receives messages and forwards them to your http endpoint.

In the event that a connection drops, the listener will attempt to reconnect while in this state. If after 5 attempts a connection cannot be made, the subscription will transtion back to the CONNECTING state. This is intended to prevent trashing between the connecting and listening states.

CANCELED

When a subscription is canceled, it reaches the CANCELED state. This state is an end state. This means once a subscription is canceled it cannnot transition to any other state. The subscription enters this state immediately when it is canceled. Subsequently Antenny closes and cleans up any listener allocated to this subscription.