[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: [OASIS Issue Tracker] (MQTT-279) Make SUBSCRIBE symmetric
[ https://issues.oasis-open.org/browse/MQTT-279?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Richard Coppen updated MQTT-279: -------------------------------- Affects Version/s: 5 > Make SUBSCRIBE symmetric > ------------------------ > > Key: MQTT-279 > URL: https://issues.oasis-open.org/browse/MQTT-279 > Project: OASIS Message Queuing Telemetry Transport (MQTT) TC > Issue Type: Improvement > Affects Versions: 5 > Reporter: Paul Fremantle > > This is a proposal that may sound a bit strange at first, so I'd ask you all to have a think about it before making up your minds! > There are a number of use cases where it would be useful to specify to a client what data it should publish. For example, there is no point a lightweight client publishing data over GPRS or another pay-per-use network when there are no subscribers at the broker. > To solve this, I suggest making the SUBSCRIBE message "symmetric". E.g the server can send a SUBSCRIBE packet to the client as well as the current client --> server packet. PUBLISH messages are already "symmetric". > The client should also support UNSUBSCRIBE. > If a client implementor does not want to implement this, they can simply return a 0x80 failure every time, making this trivially easy to implement in existing or very small clients. > I see a number of use cases, but these need fleshing out a bit more. > The simplest case would be that a client connects to the broker with a clientid (e.g. dev1032). The broker has some stored information that indicates that this clientid can be a source of messages for /device/dev1032. There are currently no subscribers to that topic, so the client just remains connected. When another client connects to the broker and subscribes, the broker could send a SUBSCRIBE to the client. This would save a lot of processing and bandwidth on the original clients part. -- This message was sent by Atlassian JIRA (v6.2.2#6258)
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]