seanmonstar
No way to set resolver or pre-resolved IP address per request.
My use case is a generic link checker for repology.org. For that I need precise control over HTTP client for predictable and stable behavior and performance. Among other things, I handle domain resolution manually, and feed pre-resolved address to HTTP client for each request.
The problem is that it's not possible to specify an address (or equally a resolver which resolves to a predefined address) during request construction, so I have to build a Client for each request. I've noticed that with native-tls this takes excessive amount of CPU spent in native_tls::TlsConnectorBuilder::build:
I've tried switching to rustls backend and it's much better, but I suspect there's its own overhead.
I've glanced through reqwest code and I see that a lot of stuff takes resolver in Client construction, so I believe it won't be trivial to move this setting to Request construction phase. Alternatively, it may be that we can leave with per-request client, if native-tls overhead is fixed, like maybe caching of whetever openssl is loading during client init.
Hi @seanmonstar, I took a look at this. It appears that DynResolver is part of our HttpConnector, and making it per-request would require significant changes. Would it be a good idea to build the HTTP connector each time? Do you have any suggestions?
