Comment by sneak

3 years ago

> I'd imagine most Go software is deployed in datacentres where the network is high quality

The problem is that those datacenters are plugged into the Internet, where the network is not always high quality. TFA mentions the Caddy webserver - this is "datacenter" software designed to talk to diverse clients all over the internet. The stdlib should not tamper with the OS defaults unless the OS defaults are pathological.

22 comments

sneak

Reply
tptacek  3 years ago

That doesn't make much sense. There are all sorts of socket and file descriptor parameters with defaults that are situational; NDELAY is one of them, as is buffer size, nonblockingness, address reuse, &c. Maybe disabling Nagle is a bad default, maybe it isn't, but the appeal to "OS defaults" is a red herring.

  • Teckla  3 years ago

    In my opinion, the Principle of Least Surprise applies here.

    Go is defaulting to surprising (unexpected) behavior.

    • giovannibajo1  3 years ago

      I think also “least surprise” depends on your background. In Go, also files don’t buffer by default, contrary to many languages including C. If you call Write() 100 times, you run exactly 100 syscalls. Intermediate Go programmers learn this and that they must explicitly manage buffering (eg: via bufio).

      I don’t think it’s wrong that sockets follow the same design. It gives me less surprise.

      6 replies →

    • squeaky-clean  3 years ago

      Only if you know that Nagle's algorithm exists and is used everywhere. For anyone with networking experience it's unexpected, but I still remember learning about Nagle's algorithm when trying to fix latency on a game server I was hosting as a teen. That was surprising behavior to me at the time.

    • jrockway  3 years ago

      Articles with titles like "How I spent 3 weeks discovering that Nagle's Algorithm exists" are a HN staple. Turning off Nagle follows the principle of least surprise. This article is the first time anyone has ever written about being surprised by Nagle's Algorithm being off.

    • Xorlev  3 years ago

      Have you ever had to chase down strange latency issues? Arguably, this behavior is the least surprising for Go's typical deployment environment.

      1 reply →

    • pclmulqdq  3 years ago

      In my experience, you usually don't want to be Nagling in code that lives in a datacenter. Go's default is likely set up around that idea.

drpixie  3 years ago

Also, for small packets, disabling consolidation means adding LOTS of packet overhead. You're not sending 1 million * 50 bytes of data, you're sending 1 million * (50 bytes of data + about 80 bytes of TCP+ethernet header).

Disabling Nagle makes sense for tiny request/replys (like RPC calls) but it's counterproductive for bulk transfers.

I'm not the only one who don't like the thought of a standard library quietly changing standard system behaviour ... so know I have to know the standard routines and their behaviour AND I have to know which platforms/libraries silently reverse things :(