We launched DNSSEC late last year and are already signing 56.9 billion DNS record sets per day. At this scale, we care a great deal about compute cost. One of the ways we save CPU cycles is our unique implementation of negative answers in DNSSEC. CC BY-SA 2.0
Go coverage with external tests
The Go test coverage implementation is quite ingenious: when asked to, the Go compiler will preprocess the source so that when each code portion is executed a bit is set in a coverage bitmap. This is integrated in the go test tool: go test -cover enables it and -coverprofile= allows
Creative foot-shooting with Go RWMutex
Hi, I'm Filippo and today I managed to surprise myself! (And not in a good way.) I'm developing a new module ("filter" as we call them) for RRDNS, CloudFlare's Go DNS server. It's a rewrite of the authoritative module, the one that adds the IP addresses to DNS answers. It
DNS parser, meet Go fuzzer
Here at CloudFlare we are heavy users of the github.com/miekg/dns Go DNS library and we make sure to contribute to its development as much as possible. Therefore when Dmitry Vyukov published go-fuzz and started to uncover tens of bugs in the Go standard library, our task was
Quick and dirty annotations for Go stack traces
CloudFlare’s DNS server, RRDNS, is entirely written in Go and typically runs tens of thousands goroutines. Since goroutines are cheap and Go I/O is blocking we run one goroutine per file descriptor we listen on and queue new packets for processing. CC BY-SA 2.0 image by wiredforlego
Go has a debugger—and it's awesome!
Something that often, uh... bugs Go developers is the lack of a proper debugger. Sure, builds are ridiculously fast and easy, and println(hex.Dump(b)) is your friend, but sometimes it would be nice to just set a breakpoint and step through that endless if chain or print a
What we've been doing with Go
Almost two years ago CloudFlare started working with Go. What started as an experiment on one network and concurrency heavy project has turned into full, production use of Go for multiple services. Today Go is at the heart of CloudFlare's services including handling compression for high-latency HTTP connections,
CloudFlare: Fastest Free DNS, Among Fastest DNS Period
CloudFlare runs one of the largest networks of DNS servers in the world. Over the last few months, we've invested in making our DNS as fast and responsive as possible. We were happy to see these efforts pay off in third-party DNS test results. The good folks at