Durable subscriptions in publish/subscribe messaging

摘要

Durable subscriptions in publish/subscribe messaging are provided. A durable subscription is received for a subscribing application. The durable subscription includes a parameter defining persistence for which a subscription is to be durable. It is detected whether the subscribing application is disconnected. In response to detecting that the subscribing application is disconnected, a filter is applies to messages to determine whether a message meets a defined persistence requirement. Only persistent messages are retained for delivery once the subscribing application is reconnected.

主权项

1. A method for durable subscriptions in publish/subscribe messaging, the method comprising:
receiving a durable subscription for a subscribing application, wherein the durable subscription includes a parameter defining persistence for which a subscription is to be durable; detecting whether the subscribing application is disconnected; responsive to detecting that the subscribing application is disconnected, applying a filter to messages to discard at a time of publication any non-persistent messages having a corresponding quality of service persistence requirement value specified by the subscribing application that identifies a message as a non-persistent message; and retaining only persistent messages having a corresponding quality of service persistence requirement value specified by the subscribing application that identifies a message as a persistent message for delivery after the subscribing application is reconnected, wherein the corresponding quality of service persistence requirement value is one of a plurality of different quality of service persistence requirement values specified by the subscribing application that identifies a particular message as a persistent message, and wherein a specified quality of service persistence requirement value of the plurality of different quality of service persistence requirement values corresponding to the particular message allows the particular message having the specified quality of service persistence requirement value to be delivered more than once to the subscribing application; wherein the parameter defining persistence is in a form of a property attached to the message.