Measuring Latency and HTTP status with elixir

[amacgregor]

I’m looking for a library that allows me to make a request to a url and measure the url latency, review the status response, headers, SSL status, etc?

Is there anything like that currently available?

[Zesky665]

You can probably use httpoison for the requests and Elixir:Time for the latency.

[Matt]

To view response, headers, etc, HTTPoison will let you do that. As far as measuring response times for a request, you could measure that with os:timestamp() or Elixir.Time.

[idi527]

I’d rather use monotonic time if the code runs on a vm to avoid skews. And keep the measurements (request, parsing, etc) in the process dictionary (if needed).

How can I get the response time of a HTTP request in elixir?

I don’t know if that would work for you (I’ve seen it being used in knutin/elli), but if all of your work is done in a single process, you can put timings into the process dictionary: defp t(key) do :erlang.put({:time, key}, :os.timestamp()) end and call it in different places inside the same process t(:start_request) # request something t(:done_requesting) t(:start_parsing_body) # parse body t(:done_parsing_body) and then collect the timings at some point later (you would need to be in th…

But replace :os.timestamp() with :erlang.monotonic_time().

[Zesky665]

@idi527

I’d rather use monotonic time if the code runs on a vm to avoid skews.

Good point

@idi527

But replace :os.timestamp() with :erlang.monotonic_time() .

There is also a monotonic_time() function in elixir System.monotonic_time().

And what cool is that in the documentation for the System module there is an example of why you should use monotonic time instead of an os:timestamp.

[cmnstmntmn]

@amacgregor have a look at https://github.com/scoutapp/elixir_plug_server_timing

[amacgregor]

Unfortunately, I’m not trying to instrument my current app but using elixir to run test against other domains.