Investigate reusing HttpClient between requests

[dakrone]

It may not need to be created every time, instead, it could be reused.

Related to #371

[dakrone]

@serioga please check out 98885eb and let me know if that works for you!

[serioga]

@dakrone do you want me to check before releasing or clojars or I can wait for release?
The commit looks promising :-)

[dakrone]

@serioga if the commit looks like it will provide what you need that's good enough for me, it'll go out in the 3.9.0 release. I just released 3.8.0 though, so it may be a little bit before another release

[serioga]

@dakrone architecturally it looks perfect 👍

[dakrone]

Excellent, it'll be in the next release then!

[aleksandersumowski]

Any timeline for 3.9 release?

I'd like to instrument my clj-http calls with X-Ray and I understand this feature would allow me to pass TracedHttpClient[1] to clj-http.

[1] https://github.com/aws/aws-xray-sdk-java/blob/master/aws-xray-recorder-sdk-apache-http/src/main/java/com/amazonaws/xray/proxies/apache/http/TracedHttpClient.java

[dakrone]

Hi @aleksandersumowski I would expect a 3.9 release sometime in the next week or so, would that work for you?

[aleksandersumowski]

yes, that would work. thanks a lot for great work!

[serioga]

Hello @dakrone

Following example looks a little bit confusing about :connection-manager key usage:

;; You can also build your own, using clj-http's helper or manually building it:
(let [cm (conn/make-reusable-conn-manager {})
      hclient (core/build-http-client {} cm "https://example.com" false)]
  (client/get "http://example.com/1"
              {:connection-manager cm :http-client hclient})
  (client/get "http://example.com/2"
              {:connection-manager cm :http-client hclient})
  (client/get "http://example.com/3"
              {:connection-manager cm :http-client hclient}))

a. Should we really specify :connection-manager after using it in core/build-http-client?

b. What happened if we use one conn-manager instance in core/build-http-client but another one as :connection-manager key?

[serioga]

ah, and parameter order is wrong in (core/build-http-client {} cm "https://example.com" false)