This is a simulator for HLS streaming clients

Installation for development:

Install node.js (e.g. sudo apt install nodejs)
Install npm (e.g. sudo apt install npm)
Clone the repository and cd into it
Edit scs.conf (currently only needed for reporting to influx)

npm i

Run SCS:

./scs <options>

Run multiple instances of SCS:

Read doc in scs-multi
Edit scs-multirc
Edit the scs command line in scs-multi

./scs-multi

Run one or a few instances of SCS on each node in a cluster:

See scs-cluster

/utilization.json

The -u option to SCS will cause it to read the file /utilization.json from the server and use the "sys_utilization" property to decide whether to spawn new clients or not, in combination with the --umax option. For this to work, a process on the server must map server load, network utilization etc to a percentage and keep the utilization.json file updated. The following is sufficient:

{
"sys_utilization": 93
}

Kill all running scs processes

pkill -f scs.js

Examples

Run two clients immediately, both reading the same stream URL

./scs -n 2 --stream-url 'https://vcache-vod.example.com/some/stream/path/playlist.m3u8?foo=10&bar=20'

Identical result as the command above:

./scs -n 2 -h vcache-vod.example.com -p https --stream-path '/some/stream/path/playlist.m3u8?foo=10&bar=20'

Run two stream clients, start both immediately, attach to vcache-vod.example.com using default protocol (https), read paths from /tmp/streams.txt:

./scs -n 2 -h vcache-vod.example.com -f /tmp/streams.txt

Note that the lines in /tmp/streams.txt should be paths, not complete URLs. If they are complete URLs, SCS will take host and protocol from the URLs and ignore the command line parameters.

Run 50 clients, start them with a random delay of up to 10 seconds, otherwise as above:

./scs -n 50 -d 10 -h vcache-vod.example.com -f /tmp/streams.txt

Start 10 % of clients immediately, ramp quickly to 200 clients, keep trying to add more clients as long as server still seems ok

./scs --immediate 10 -n 200 --dynamic -h vcache-vod.example.com -f /tmp/streams.txt

daghf/scs