docker-dangling-http

A small node webservice to be used under HTTP load test. Use querystring parameters to modify how quickly (or not) the service responds.

Development

1. Clone repo, cd docker-dangling-http
2. Install dependencies, npm i
3. Run the app npm start or node index

Usage (Docker)

• Available on Docker Hub bryanlatten/docker-dangling-http
• docker run --rm -p 3000:3000 bryanlatten/docker-dangling-http
• Make HTTP requests against the docker-machine IP + port (3000) or localhost:3000 (linux + docker4mac/win) with the following querystring variables, which may be combined:

Querystring	Name	Example	Default	Description
d	Delay	/?d=30	0	Seconds to delay before HTTP response is sent
r	Random	/?r=30	0	Adds time to delay, randomly, up to provided value
e	Empty	/?e=1	0	Prematurely breaks HTTP connection, with empty response

Example

Note: service is running locally (on 127.0.0.1:3000) via npm start

• Request completed, immediately

$ curl 127.0.0.1:3000
[Response from 127.0.0.1]
  - not delayed

• Request completed, after 30 seconds delay

$ curl 127.0.0.1:3000/\?d=30
[Response from 127.0.0.1]
  - delayed 30s

• Request completed, minimum 10 seconds delay, with additional random 5 seconds

$ curl 127.0.0.1:3000/\?d=10\&r=5
[Response from 127.0.0.1]
  - adding 3s random delay (max 5s)
  - delayed 13s

• Request ended, broken, after 15 seconds delay

$ curl 127.0.0.1:3000/\?d=15\&e=1
curl: (52) Empty reply from server

Console log from the above request "broken" confirms:

Request from ::ffff:127.0.0.1, delayed 15s, prematurely breaking connection

Load testing example

$ ab -c 3 -n 10 127.0.0.1:3000/\?d=1

Results:

This is ApacheBench, Version 2.3 <$Revision: 1796539 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient).....done


Server Software:
Server Hostname:        127.0.0.1
Server Port:            3000

Document Path:          /?d=1
Document Length:        40 bytes

Concurrency Level:      3
Time taken for tests:   4.009 seconds
Complete requests:      10
Failed requests:        0
Total transferred:      1380 bytes
HTML transferred:       400 bytes
Requests per second:    2.49 [#/sec] (mean)
Time per request:       1202.723 [ms] (mean)
Time per request:       400.908 [ms] (mean, across all concurrent requests)
Transfer rate:          0.34 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.1      0       0
Processing:  1002 1002   0.3   1002    1002
Waiting:     1001 1002   0.2   1002    1002
Total:       1002 1002   0.2   1002    1003

Percentage of the requests served within a certain time (ms)
  50%   1002
  66%   1002
  75%   1002
  80%   1002
  90%   1003
  95%   1003
  98%   1003
  99%   1003
 100%   1003 (longest request)

Run with Kubernetes

Responds to HTTP traffic from standard benchmarking tools (ab, jmeter, gatling, locust.io)

• kubernetes.yaml: sample Kubernetes Pod definition