Chunked Requests

If you’re handling HTTP POSTs, it’s very possible that your browser or non-browser clients will send requests using chunked transfer encoding. This part of HTTP 1.1 is great for keeping messages short, but not so great for short and simple NIO servers.

An Inconvenient Party Line

The challenge for your server, as it is handling many concurrent requests, is to maintain the state of a message that is split into many chunks. For example if the request body contains url-encoded parameters, you must assemble all the chunks together to have uniform access to any parameter.

Netty provides a simple solution for cases like this: its HttpChunkAggregator assembles chunks into a single message. The caveat is that the full message is necessarily loaded into memory, and it could be arbitrarily large. The interface therefore requires you to chose a limit for the aggregated message size; any chunked request that exceeds this limit will raise a TooLongFrameException. (For general file upload support, see the netty-uploads module.)

Unfiltered’s Netty server-builder provides a convenient chunked interface for adding aggregating handlers to your pipeline:

unfiltered.netty.Server(8080).chunked(1048576).plan(hello).run()

If you want quick, easy, and limited support for chunked requests, don’t forget to call this method on your server builder.