Create and run performance tests using Clojure (and get fancy reports). For reporting clj-gatling uses Gatling under the hood.

Add the following to your project.clj :dependencies:

[clj-gatling "0.4.0"]

This will make 100 simultaneous http get requests to localhost. Single request is considered to be ok if it returns http status code 200.

(use 'clj-gatling.core)

(run-simulation
  [{:name "Localhost test cenario"
   :requests [{:name "Root request" :http "http://localhost"}]}] 100)

Simulation run shows some important statistics in console and also generates exactly the same kind of a html report that Gatling does. (clj-gatling uses Gatling internally to do this)

clj-gatling runs scenarios concurrently. Scenario consists of one or more steps called requests. Scenario is defined as a Clojure map.

{:name "Order book scenario"
 :requests [{:name "Open frontpage" :fn open-frontpage}
            {:name "Select book"    :fn select-book
             :name "Pay order"      :fn pay-order}]}

Scenario above consists of three requests. Requests are defined as a Clojure maps. In request you can specify actual action either by giving keyword :http which will do http get request or by giving :fn keyword which lets you to specify your own function. The latter option is a preferred way in clj-gatling.

Your own functions should look like this:

(defn open-frontpage [user-id context callback]
  (let [was-call-succesful? (do-your-call-here)
    (callback was-call-succesful? context)))

Ideally your calls should be asynchronous and non-blocking. That's why in function signature clj-gatling uses callback instead of function return value. When calling callback function the first parameter is boolean which tells clj-gatling whether call was succesful.

The second parameter to callback is context that is passed through requests within same scenario and virtual user. You can utilize it in a following way:

;In "Select book" request
(callback true (assoc context :book-id 1}))

;And then in next requst
(defn pay-order [user-id context callback]
  (pay-order-call-with-book-id (:book-id context))
    ...)

By default clj-gatling uses timeout for 5000 ms for all functions. You can override that behaviour by setting option :timeout-in-ms

You can run same scenario multiple times to generate constant load within a longer time period by specifying option :requests. Default number of requests is same as number of users (which means run only once)

(run-simulation [test-scenario] 10 {:requests 500})

You can run same scenario multiple times within given time period to generate constant load by specifying option :duration.

(require '[clj-time.core :as t])

(run-simulation [test-scenario] 10 {:duration (t/minutes 2)})

Copyright (C) 2014 Markus Hjort

Distributed under the Eclipse Public License, the same as Clojure.