… Is this a trick question? The object, provided by the library (net/http which is about as default as they come) sets “DefaultMaxIdleConnsPerHost” to 2. This is significant because if you finish a connection and you’ve got more than 2 idles, it slams that connection close. If you have a lot of simultaneous fast lived requests to the same IP (say a load balanced IP), your go programs will exhaust the ephemeral port list quickly. It’s one of the most common “gotchas” I see where Go programs work great in dev and blow themselves apart in prod.
It’s safe to assume that any non-trivial program written in Go is multithreaded
And yet: You’ll still be limited to two simultaneous calls to your REST API because the default HTTP client was built in the dumbest way possible.
The client object or the library?
… Is this a trick question? The object, provided by the library (net/http which is about as default as they come) sets “DefaultMaxIdleConnsPerHost” to 2. This is significant because if you finish a connection and you’ve got more than 2 idles, it slams that connection close. If you have a lot of simultaneous fast lived requests to the same IP (say a load balanced IP), your go programs will exhaust the ephemeral port list quickly. It’s one of the most common “gotchas” I see where Go programs work great in dev and blow themselves apart in prod.
https://dev.to/gkampitakis/http-connection-churn-in-go-34pl is a fairly decent write up.
Really? Huh, TIL. I guess I’ve just never run into a situation where that was the bottleneck.