How to disable Nagle's algorithm in ServiceStack?

Question

We're using ServiceStack 3.9.71.0 and we're currently experiencing unexplained latency issues with clients over a WAN connection.

A reply with a very small payload (<100 bytes) is received after 200ms+.

The round-trip-time (RTT) on the link is about 40ms due to the geographical distance. This has been verified by pinging the other host and using a simple echo service to test the latency of a TCP connection.

Both ping and echo test show latencies which are in line with expectations. Getting a reply from our ServiceStack host takes much longer than expected.

We've verified that:

• WAN link is only running at 25% of capacity (no congestion)
• No QOS is employed on the WAN link
• same host gives fast reply to same request from a different host on local network
• delay is not caused by our code processing the request

We've now stumbled across Nagle's algorithm and that it can mean delays for small requests on WAN networks (http://blogs.msdn.com/b/windowsazurestorage/archive/2010/06/25/nagle-s-algorithm-is-not-friendly-towards-small-requests.aspx).

In .NET it can be disabled by setting TcpClient.NoDelay = true (https://msdn.microsoft.com/en-us/en-US/library/system.net.sockets.tcpclient.nodelay(v=vs.110).aspx).

How can this be disabled for ServiceStack's TCP handling?

EDIT: I don't think that this is a duplicate of HttpWebRequest is slow with chunked data. The mentioned question covers HttpWebRequest which isn't used by ServiceStack. ServiceStack uses HttpListener which also happens to be controlled / managed by the mentioned ServicePointManager. We're going to conduct a test to see whether setting ServicePointManager.UseNagleAlgorithm = false solves the issue.

Answer 1

I think you provided an answer in your Update UseNagleAlgorithm = false should solve this issue. But be careful because ServicePointManager.UseNagleAlgorithm = false; is a global settings which means it will turn off this algorithm for all of your endpoint and for all of your requests in the entire App Domain. When you call more than one service endpoints (usually that is the case) with mixed sized of Request it will bite back. So you should consider setting this only for one specific ServicePoint, you can acquire it by:

ServicePoint sp = ServicePointManager.FindServicePoint(<uri>);
sp.UseNagleAlgorithm = false;

and not set it globally

Here is an article about it: https://technet2.github.io/Wiki/blogs/windowsazurestorage/nagles-algorithm-is-not-friendly-towards-small-requests.html