Jon Pretty

I'm sure @alxarchambault knows this, but basically every Ivy resolution with SBT seems to involve a 302 redirect to another 302 which leads to a 404, for a couple of resolvers before getting a 200. Those 302s and 404s (as per protocol) don't get cached.

Only one repository (Central) should be involved in the benchmark project, which should limit these kind of failed attempts. That said, I haven't checked whether sbt checks other repositories too here (might be good to ensure that it doesn't).

I was trying to improve downloads at Scala World, so with a "default" configuration, I ran SBT through a proxy server, and noticed about 6 HTTP requests to various repositories (e.g. typesafe) before fetching most files. I think this is typical.

Isn't that just the order your resolvers are declared in though?

There are more repositories for plugins for sure. I re-order them in sbt-coursier, to avoid those that feel slow (https://github.com/coursier/coursier/blob/06322622188f2e458b15204e05f4cefa99321df3/sbt-coursier/src/main/scala/coursier/Tasks.scala#L101 …).

Reordering seems worthwhile. Though IIRC (I don't have it set up any more) the default settings search the Typesafe repo for every file prior to Maven Central, which just adds a fraction of a second to each dependency, because only a few files actually exist on Typesafe.

Yeah, but that only applies to plugins then (the benchmark here is ok).