Limit download file width / speed in Servlet

Question

we got a high load java application that works in cluster mode.

I need to add the ability to download and upload files for our clients. I am going to store the files in the user’s gridFs, but I'm not sure if this is the best choice, but mongo can be clustered, and mongo can replicate data between diff nodes. This is exactly what I need.

Different user groups should be limited by different bandwidth. Based on some business rules, I should limit the download speed for some users. I saw several solutions for this

Most of them work the same.

• Read a bunch of bytes
• Sleepy thread
• Repeat

Mongo just provided me with an InputStrem, and I can read from this stream and write to the servlet output stream. I am not sure if this is a valid approach. In addition, I am afraid that users may create many juicy threads at boot time, and this may hurt performance.

Could this be a problem for the servlet container?

If this can be a problem, how can it be avoided? perhaps using nio?

I prefer to use a purely java solution.

Any help would be greatly appreciated.

Answer 1

A leaky bucket or token can be used to control network bandwidth.

EDIT: I did a little prototyping and implemented an algorithm using asynchronous servlet 3.0 processing. The results are pretty good. Full source code can be found on GitHub . Enjoy!

Answer 2

I am also afraid that users might create a lot of juicy threads at boot time, and that could hurt performance.

Could this be a problem for the servlet container?

Yes it is possible.

If this can be a problem, how can it be avoided? perhaps using nio?

NIO will not help on its own. This, of course, does not interfere with low-bandwidth responses linking streams over long periods of time.

I think that you will need to do the download in a special web container. I'm not sure, but I think Servlet 3.0 with asynchronous mode can do the trick.