[yoda] > I really need help because my application currently can't scale. Some > user's end up getting their data 30 seconds after generation(best case) > and up to 5 minutes after content generation. This is simply > unacceptable. The subscribers deserve much better service if my > startup is to survive in the market.
> My questions therefore are: > 1)Should I switch to stackless python or should I carry out experiments > with mutlithreading the application? > 2)What architectural suggestions can you give me? > 3)Has anyone encountered such a situation before? How did you deal with > it? > 4)Lastly, and probably most controversial: Is python the right language > for this? I really don't want to switch to Lisp, Icon or Erlang as yet. I highly recommend reading the following paper on the architecture of highly concurrent systems. A Design Framework for Highly Concurrent Systems, Welsh et al. http://www.eecs.harvard.edu/~mdw/papers/events.pdf The key principle that I see being applicable to your scenario is to have a fixed number of delivery processes/threads. Welsh terms this the "width" of your delivery channel. The number should match the number of "delivery channels" that your infrastructure can support. If you are delivering your SMSs by SMPP, then there is probably a limit to the number of messages/second that your outgoing SMPP server can handle. If you go above that limit, then you might cause thrashing or overload in that server. If you're delivering by an actual GSM mobile connected serially connected to your server/pc, then you should have a single delivery process/thread for each connected mobile. These delivery processes/threads would be fed by queues of outgoing SMSs. If you want to use a multithreaded design, then simply use a python Queue.Queue for each delivery channel. If you want to use a multi-process design, devise a simple protocol for communicating those messages from your generating database/process to your delivery channel over TCP sockets. As explained in Welsh's paper, you will get the highest stability ensuring that your delivery channels only receive as many messages as the outgoing transmission mechanism can actually handle. If you devise a multi-process solution, using TCP sockets to distribute messages from your generating application to your delivery channels, then it would be very straightforward to scale that up to multiple processes running on a either a multiple-core-cpu, a multiple-cpu-server, or a multiple-server-network. All of this should be achievable with python. Some questions: 1. How are you transmitting your SMSs? 2. If you disable the actual transmission, how many SMSs can your application generate per second? HTH, -- alan kennedy ------------------------------------------------------ email alan: http://xhaus.com/contact/alan -- http://mail.python.org/mailman/listinfo/python-list
