github.com/loveholidays/ripley

ripley - replay HTTP

Ripley replays HTTP traffic at multiples of the original rate. It simulates traffic ramp up or down by specifying rate phases for each run. For example, you can replay HTTP requests at twice the original rate for ten minutes, then three times the original rate for five minutes, then ten times the original rate for an hour and so on. Ripley's original use case is load testing by replaying HTTP access logs from production applications.

Quickstart

Clone and build ripley

git clone [e-mail]:loveholidays/ripley.git
cd ripley
go build -o ripley main.go

Run a web server to replay traffic against

go run etc/dummyweb.go

Loop 10 times over a set of HTTP requests at 1x rate for 10 seconds, then at 5x for 10 seconds, then at 10x for the remaining requests

seq 10 | xargs -i cat etc/requests.jsonl | ./ripley -pace "10s@1 10s@5 1h@10"

Replaying HTTP traffic

Ripley reads a representation of HTTP requests in JSON Lines format from STDIN and replays them at different rates in phases as specified by the -pace flag.

An example ripley request:

{
    "url": "http://localhost:8080/",
    "verb": "GET",
    "timestamp": "2021-11-08T18:59:59.9Z",
    "headers": {"Accept": "text/plain"}
}

url, verb and timestamp are required, headers are optional.

-pace specifies rate phases in [duration]@[rate] format. For example, 10s@5 5m@10 1h30m@100 means replay traffic at 5x for 10 seconds, 10x for 5 minutes and 100x for one and a half hours. The run will stop either when ripley stops receiving requests from STDIN or when the last phase elapses, whichever happens first.

Ripley writes request results as JSON Lines to STDOUT

echo '{"url": "http://localhost:8080/", "verb": "GET", "timestamp": "2021-11-08T18:59:50.9Z"}' | ./ripley | jq

produces

{
  "statusCode": 200,
  "latency": 3915447,
  "request": {
    "verb": "GET",
    "url": "http://localhost:8080/",
    "body": "",
    "timestamp": "2021-11-08T18:59:50.9Z",
    "headers": null
  }
}

Results output can be suppressed using the -silent flag.

It is possible to collect and print a run's statistics:

seq 10 | xargs -i cat etc/requests.jsonl | ./ripley -pace "10s@1 10s@5 1h@10" -silent -stats | jq

{
  "totalRequests": 100,
  "statusCodes": {
    "200": 100
  },
  "latencyMicroseconds": {
    "max": 2960,
    "mean": 2008.25,
    "median": 2085.5,
    "min": 815,
    "p95": 2577,
    "p99": 2876,
    "stdDev": 449.1945986986041
  }
}

Running the tests

go test pkg/*go