Posts by Marek Majkowski

The curious case of slow downloads

Published on by Marek Majkowski.

Some time ago we discovered that certain very slow downloads were getting abruptly terminated and began investigating whether that was a client (i.e. web browser) or server (i.e. us) problem. Some users were unable to download a binary file a few megabytes in length. The story was simple—

The revenge of the listening sockets

Published on by Marek Majkowski.

Back in November we wrote a blog post about one latency spike. Today I'd like to share a continuation of that story. As it turns out, the misconfigured rmem setting wasn't the only source of added latency. It looked like Mr Wolf hadn't finished his job. After adjusting the previously

400Gbps: Winter of Whopping Weekend DDoS Attacks

Published on by Marek Majkowski.

Over the last month, we’ve been watching some of the largest distributed denial of service (DDoS) attacks ever seen unfold. As CloudFlare has grown we've brought on line systems capable of absorbing and accurately measuring attacks. Since we don't need to resort to crude techniques to block traffic we