Thor

Thor is WebSocket benchmarking/load generator. There are a lot of benchmarking tools for HTTP servers. You've got ab, siege, wrk and more. But all these tools only work with plain ol HTTP and have no support for WebSockets - even if they did they wouldn't be suitable, as they would be testing short running HTTP requests instead of long running HTTP requests with a lot of messaging traffic. Thor fixes all of this.

Dependencies

Thor requires Node.js to be installed on your system. If you don't have Node.js installed you can download it from http://nodejs.org or build it from the github source repository: http://github.com/joyent/node.

Once you have Node.js installed, you can use the bundled package manager npm to install this module:

npm install -g thor

The -g command flag tells npm to install the module globally on your system.

Usage

thor [options] <urls>

Thor can hit multiple URL's at once; this is useful if you are testing your reverse proxies, load balancers or just simply multiple applications. The url that you supply to thor should be written in a WebSocket compatible format using the ws or wss protocols:

thor --amount 5000 ws://localhost:8080 wss://localhost:8081

The snippet above will open up 5000 connections against the regular ws://localhost:8080 and also 5000 connections against the secured wss://localhost:8081 server, so a total of 10000 connections will be made.

One thing to keep in mind is you probably need to bump the amount of file descriptors on your local machine if you start testing WebSockets. Set the ulimit -n on machine as high as possible. If you do not know how to do this, Google it.

Options

Usage: thor [options] ws://localhost

Options:

-h, --help output usage information

-A, --amount <connections> the amount of persistent connections to generate

-C, --concurrent <connections> how many concurrent-connections per second

-M, --messages <messages> messages to be send per connection

-P, --protocol <protocol> WebSocket protocol version

-B, --buffer <size> size of the messages that are send

-W, --workers <cpus> workers to be spawned

-G, --generator <file> custom message generators

-M, --masked send the messaged with a mask

-b, --binary send binary messages instead of utf-8

-V, --version output the version number

Some small notes about the options:

--protocol is the protocol version number. If you want to use the HyBi drafts 07-12 use 8 as argument or if you want to use the HyBi drafts 13-17 drafts which are the default version use 13.

--buffer should be size of the message in bytes.

--workers as Node.js is single threaded this sets the amount of sub processes to handle all the heavy lifting.

Custom messages

Some WebSocket servers have their own custom messaging protocol. In order to work with those servers we introduced a concept called generators a generator is a small JavaScript file that can output utf8 and binary messages. It uses a really simple generator by default.

Checkout https://github.com/observing/thor/blob/master/generator.js for an example of a generator.

thor --amount 1000 --generator <file.js> ws://localhost:8080

Example

thor --amount 1000 --messages 100 ws://localhost:8080

This will hit the WebSocket server that runs on localhost:8080 with 1000 connections and sends 100 messages over each established connection. Once thor is done with smashing your connections it will generate a detailed report:

Thor: version: 1.0.0

God of Thunder, son of Odin and smasher of WebSockets!

Thou shall:

- Spawn 4 workers.

- Create all the concurrent/parallel connections.

- Smash 1000 connections with the mighty Mjölnir.

The answers you seek shall be yours, once I claim what is mine.

Connecting to ws://localhost:8080

Opened 100 connections

Opened 200 connections

Opened 300 connections

Opened 400 connections

Opened 500 connections

Opened 600 connections

Opened 700 connections

Opened 800 connections

Opened 900 connections

Opened 1000 connections

Online 15000 milliseconds

Time taken 31775 milliseconds

Connected 1000

Disconnected 0

Failed 0

Total transferred 120.46MB

Total received 120.43MB

Durations (ms):

min mean stddev median max

Handshaking 217 5036 4094 3902 14451

Latency 0 215 104 205 701

Percentile (ms):

50% 66% 75% 80% 90% 95% 98% 98% 100%

Handshaking 3902 6425 8273 9141 11409 12904 13382 13945 14451

Latency 205 246 266 288 371 413 437 443 701

License

MIT