Stress Test noPoll

A simple client/server program to stress test noPoll library

http://www.aspl.es/nopoll/  — An OpenSource WebSocket Toolkit

The test program implements a simple client/server protocol over websocket. The client sends a text message to the server asking it to send back binary messages of a specified length repeated back to back a specified number of times. It picks random value for message size and repeat count. The server sends back the requested number of messages as fast as possible. The client verifies that all messages are retrieved properly. The client then repeats with another random value for message size and repeat count. After running this in a loop for a specified duration (in seconds) the client quits.

Both the client and server abort as soon as any unexpected event occurs.

Multiple clients can connect to a single server. The server responds to each client individually according to the requests it makes.

Compile and Run

To compile, run make. The noPoll library is expected to be installed in your home directory under folder libnopoll. Tested on Debian/Jessie.

The single executable can run as a websocket server or client depending on first argument.

First invoke the executable as a websocket server at some port (say 12020)

./test_nopoll server 12020

Then, in another console (on same or another host PC) invoke the executable as a client.

./test_nopoll client xyz 127.0.0.1 12020 5

The second argument is an 'id' that can be any random string. It is used to prefix log messages and allows to distinguish messages from multiple clients running on the same console.

The third and fourth arguments are the host IP Address and port to connect to.

The last argument is the duration of the client test run in seconds.

Debug Logs

Before running the executable, you can set two environmental variables to control debug output:

export NOPOLL_TEST_DEBUG=1

Setting this enables printing test application’s log output. These go to standard error. Each message is prefixed with its 'id'.

export NOPOLL_TEST_DEBUG_NOPOLL=1

Setting this enables printing noPoll library’s internal debug output. These all go to a file. The file is named nopoll_'id'.log for client side and nopoll_server.log for server side logs.

Stress Testing

A wrapper shell script 'nopoll_stress_test.sh' spawns off multiple test_nopoll client processes simultaneously and waits for all of them to finish.

For example, to run 5 clients for 10 seconds each connecting to a server instance running on host 10.1.2.3 at port 12020 run:

./nopoll_stress_test.sh 10.1.2.3 12020 10 5

Each client is started with a unique id (an incrementing integer). The output will give some idea of how long it took to establish each connection and the number of messages retrieved by each client. If noPolls internal logging is enabled, it will create multiple log files, one for each client.

Server Implementation in Node.js

Also available is an implementation of the server side of the test case protocol using Node.js. This can be used to compare noPoll based client performance against the alternate implementation of the server.

To install, first ensure node/npm is installed on the system. Then in the checked out test-nopoll directory run:

npm install websocket.

Then run node.js based websocket server at desired port. For example:

node test_nopoll_server.js 12020