On Aug 11, 12:27 pm, "Yaroslav G." <[email protected]> wrote: > Hello! > > I’d like to share some concepts with community regarding asynchronous > operations in Rails, hoping for feedback and advice. > We (Helicon Tech) currently work on Ruby > on Rails implementation for > Microsoft IIS. Our goal is to make RoR available for shared Windows > hostings and developers. We currently work with several small hostings > to implement RoR shared hosting solution with them as proof of concept. > > So I was thinking… since we already have a working asynchronous server > implementation and asynchronous (after some tweaking) implementation of > FastCGI, we may utilize it to bring async into the RoR applications. > > Our concept is quite easy. I will show it on a simple chat application > example: Our server creates a fiber and puts a Rack call into the fiber > body, so all RoR code, like controller is executed inside a fiber. There > is a script to wait for new messages, which simply yields (suspends) a > fiber. So there could be number, maybe thousands of suspended fibers at > a time. When new message is received it is put into the storage and all > fibers waiting for it are resumed. They process messages, return > responses to their clients and then clients makes another request to a > wait script. > > We have working proof of concept for it, but I need a feedback from the > community. Whether this future is needed at all and what possible > problems and flaws I need to take into consideration? >
Personally I worry slightly about ruby's ability to handle several thousand IO streams. Does it use efficient select alternatives like epoll or queues on platforms that support them? The last time I did something like this I wrote the comet part as a C++ daemon. When events like a message being posted occurred, the rails code notified the C++ daemon, that in turn notified any clients that had registered an interest in the relevant event. I'd also worry about how your model handles the case where your web front ends are spread across several servers - if the request with a new chat message arrives at server A but some of the waiting fibers are on server B, how does the message get passed across ? > Also I am thinking on how to extend this concept to bring more > asynchronous operations into RoR. Imagine we have some time consuming > operation in the script. Like we are requesting whether forecast data > from remote server for analysis. We could start an asynchronous http > request operation, setting up a resume of current fiber as a callback, > and then suspend current fiber, allowing other requests to be served. > Such system could handle much more load that a synchronous system. > Unfortunately I cannot find appropriate concept of asynchronous > operations for Ruby – how to do an async HTTP request? Some use > 'eventmachine' to do this. But while providing some asynchronous > operation support inside event loop, the loop itself completely blocks > execution thread. I think we may try to put our entire client-server > conversation into the event loop, need to try it first. > Anyway any feedback and suggestions are greatly appreciated. I think with event machine you do pretty much have to give yourself over entirely to event machine and do everything using the event driven mechanisms it provides. Fred > > Thank you! > > -- > Posted viahttp://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
