How many concurrent upload can a Rails App handle

Question

We are expect to serve few thousands uploads within 2 or 3 minutes. Most of the uploads will be about 20 -> 200 Mb. Technically, I think upload has not much to do with Rails, but rather the WebServer (Apache/Nginx), so as long as the server can handle concurrent requests, then there not much work for Rails app to do (except to move the file to proper storage and to create database record to track the file).

Is my assumption right? Normally, how many concurrent uploads a single Rails App process can be expected to handle? (Given the Rails App could take 20 ms with all the calculation, moving file and create database record, but the connection must be kept alive for 1 minute so that the file can be successful transferred)

Answer 1

Not really but close. A single rails application instance can only handle a single request at a time but it's easy to use a server that has a pool of these instances using nginx and passenger or mongrels and a load balancer.

You should create a load test to confirm any of your assumptions.

I would use curl to simulate 10/100/1000 users uploading a few megabytes using multiple processes and tune the upload speed to simulate slow clients to see how that affects your performance. Measure the response times for 10 concurrent requests and record and observe the results.

You could use the nginx upload module and by-pass rails if you can and if that helps. Always test your assumptions.