Comment by 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.

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tptacek

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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.

    • blibble  3 years ago

      that Write() doesn't call fsync() though, does it?

      so there's no buffering going on in the application, but the bytes almost certainly don't hit the disk before Write() returns

      they've just been staged into an OS buffer, with the OS promising to write them out to the disk at a later time (probably, maybe...? hopefully!)

      which is exactly the same as a regular TCP socket (with Nagle disabled, i.e. the default, non Go way)

      2 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.

    • lanstin  3 years ago

      Twice I have run into this behavior having known and forgotten it. Chatty non http protocols with a few small messages doing auth or whatever before bulk data flow. Pissed me off and surprised me. Now I make sure my defaults for any framework I am using are no delay, and I make sure to plug my computing device into Ethernet whenever possible.

  • 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.

Terretta  3 years ago

You guys had this convo before, in 2015, on what the interaction of the two settings should be doing:

https://news.ycombinator.com/item?id=34180239