Agents 'n' timeouts

[flintinatux]

Lots of ooey-gooey deliciousness in this one.

First up: Agents. They help "manage connection persistence". In a nutshell, they can help you reuse a pool of sockets for a given host and port, so you don't need a new TCP connection for every request. Think about any application making lots of requests in a row to an upstream service.

Also included: timeouts. Sometimes your upstream service is unreliable, and just hangs. You'd like the option to end the relationship early and try again with another socket. Now you can pass the timeout option, and when the request times out, you can backoff based on errors with a code of 'ECONNRESET'. I'm sure you can think of other reasons to timeout, but here's a quick example:

const { backoff } = require('@articulate/funky')
const gimme = require('@articulate/gimme')
const { prop, propEq } = require('tinyfunk')

const request = () =>
  gimme({ url, timeout: 1000 }).then(prop('body'))

const when =
  propEq('code', 'ECONNRESET')

const getTheStuff =
  backoff({ base: 250, tries: 4, when }, request)

to review:

• Wait for the green check.
• Read the updated docs.
• For extra credit, try adding an Agent to a service or script of your choice:
  • Set it up with const agent = new Agent({ keepAlive: true })
  • Don't forget to agent.destroy() when everything is done. Your OS will thank you for releasing the sockets.
• Find a squirrel agent who is out of time.

Fixes #12

[spencerfdavis]

Code looks good 👍

[mgreystone]

Code review only. I attempted to bump okta-profile-monitor but tests got quite upset, & i can't fall in that rabbit hole at the moment.

[rpearce]

code lookin 👌

[mgreystone]

I am failing to figure out how to test effectively. How do i know which agent is being used or the state of the tcp socket at a given time?

Code looks good to me, though, & i definitely see the value in this. 👍

[flintinatux]

Yeah, I get that. I added it to a script of mine, and it cut the runtime by 40%, so that was the biggest sign for me that it was working.

[flintinatux]