Category: Congestion

  • Performance Diagnostics Part 5- Optimising Worker Threads

    Background A few (ok many) years ago I was working with a customer who was launching a new application and was expecting a high load on their launch, which for whatever reason was at 3pm on a Friday (1). As 3pm hit, and the load balancers started directing traffic to the now production system, there…

  • Initial Congestion Windows in Linux

    As part of my research I’ve spent a lot of time looking the performance of TCP variants and options. One of the most common questions I get asked is about the congestion window and how it reacts to change in the environment. The congestion window (CWND) is used to control how many segments (layer 4…