My current use case is pretty simple, being able to push requests to the remote devices, and gather the data back, assuming the remote devices (clients) are already connected to the server, which is a client-related problem with any messaging solution.
I learn about MQTT when looking for alternatives to Google Cloud Messaging for Android (which is built on to of XMPP). Facebook Messenger uses MQTT. I don't want to develop an overkill solution that could delay deliverance of value to my customer, though I find implementing an MQ/MQTT solution intellectually challenging. I even read the standard a few months ago, and it seems to be simpler than expected. I'd love to go down the "implement MQTT server in Pharo", I would lose a real MQ scalability, but it could be a good way to learn the protocol, and an alternative to Mosquitto [1] with the benefits of having a server inside the image. Do you have experience with the scalability of Zinc WebSockets? How many of them can a single Pharo image handle? The I/O would be minimal (< 1KB) per message, and the requests would be measured in minutes instead of seconds. Although a 50 ws frames/sec peak during a couple of seconds is feasible. Regards, [1] http://mosquitto.org/ El Wed Nov 19 2014 at 4:22:56 PM, Sven Van Caekenberghe <s...@stfx.eu> escribió: > Hey Esteban, > > Since you seem to need to scale to 1000s of concurrent connections, I > would go for option 2. RabbitMQ will then work as a demultiplexer and you > gain options for using more than one Pharo worker for processing traffic, > if that ever becomes necessary. > > BTW, I never heard of MQTT and it seems pretty interesting, thanks ! I > will read about it tonight. > > Sven > > > On 19 Nov 2014, at 19:06, Esteban A. Maringolo <emaring...@gmail.com> > wrote: > > > > Hi, > > > > I'll be needing to add bidirectional messaging to our current Android > (Java) application, and as usual I'm expecting to manage the server side of > the communication with Pharo. > > > > I'm evaluating two alternatives, but I'm in open to other, proven, > options. > > > > Option 1. WebSockets > > Open a WebSocket on each device, and push/retrieve messages from each of > these, tracking the device id if I need to recreate a new socket (avoiding > recreating new sockets in case of connectivity issues, very common). > > > > Option 2. MQTT [1] > > This is basically a mobile oriented MQ, super low footprint on mobile. > > For what I saw, I could implement the server using an intermediate MQ > (RabbitMQ) and use STOMP to connect to it. > > > > Option 3. XMPP [3] > > Provides several features I'll need in the future, like file transfer in > addition to regular text messaging. It is very well supported in Android > with Smack [4], but I don't know if we have a Pharo server for it, or if > somebody ever played with it. > > > > By means of simplicity and use load I favor option 1, because I can > understand it better, and as everything moves towards web based > technologies, I could implement WAMP [5] on top of that in the future. > > > > Right now I'd need to have a hundred websockets opened at the same time, > which doesn't sound like a heavy load to me, but I certainly don't know. In > the future it could be an order of magnitude bigger, and that's why I don't > discard more complex solutions like XMPP or MQTT. > > > > Regards! > > > > > > [1] http://mqtt.org/ > > [2] https://github.com/svenvc/docs/blob/master/neo/stamp.md > > [3] http://xmpp.org/ > > [4] http://www.igniterealtime.org/projects/smack/ > > [5] http://wamp.ws/ > > > > > > >
