System with two asynchronous processes

Question

I'm planning to write a system which should accept input from users (from browser), make some calculations and show updated data to all users, currently visiting certain website.

Input can come one time in a hour, but can also come 100 times each second. It is VERY important not to loose any of user inputs, but really register and process ALL of them.

So, the idea was to create two programs. One will receive data (input) from browser and store it somehow in a queue (maybe an array, to be really fast?). Second program should wait until there are new items in the queue (saving resources) and then became active and begin to process the queue items. Both programs should run asynchronously.

I can php, so I would write first program using php. But I'm not sure about second part.. I'm not sure about how to send an event from first to second program. I need some advice at this point. Threads are not possible with php? I need some ideas how to create the system like i discribed.

I would use comet server to communicate feedback to the website the input came from (this part already tested)

Answer 1

As per the comments above, trivially you appear to be describing a message queueing / processing system, however looking at your question in more depth this is probably not the case:

Both programs should run asynchronously.

Having a program which process a request from a browser but does it asynchronously is an oxymoron. While you could handle the enqueueing of a message after dealing with the HTTP request, its still a synchronous process.

It is VERY important not to loose any of user inputs

PHP is not a good language for writing control systems for nuclear reactors (nor, according to Microsoft, is Java). HTTP and TCP/IP are not ideal for real time systems either.

100 times each second

Sorry - I thought you meant there could be a lot of concurrent requests. This is not a huge amount.

You seem to be confusing the objective of using COMET / Ajax with asynchronous processing of the application. Even with very large amounts of data, it should be possible to handle the interaction using a single php script working synchronously.