swails/mqtt_stress_tester

Bombards MQTT brokers with connections and messages to test broker performance under load

Stress Tester

This is a MQTT broker stress tester designed to determine the capacity of a broker by bombarding it with concurrent messages.

This program is written in the Go programming language and was developed and tested with Go 1.6.

Prerequisites

You need to have Go installed. This program was tested with Go 1.6 and later versions should work. Earlier versions should as well, although are untested.

Building

Build this program with the command

make all

Testing

You can run the unit-tests with the command

make test

Running

The command-line usage can be requested with the --help or -h flags:

bash$ mqtt_stresser -h
Usage:
  mqtt_stresser [OPTIONS]

Broker Connection Options:
      --hostname=            Address of the broker to connect to (default:
                             localhost)
      --passwd-file=         File with raw-text usernames and passwords
  -u, --username=            Name of the user to connect with. Superceded by
                             --passwd-file if specified
  -P, --password=            Password of the user to connect with. Used in
                             tandem with username
  -p, --port=                The port to connect through (default: 1883)

Publish/Subscribe Options:
  -n, --num-publishers=      Number of concurrent publishers (default: 1)
  -m, --messages-per-second= Average number of messages per second to send from
                             each publisher (default: 10)
  -d, --duration=            Number of seconds to run the publishers for
                             (default: 5)
  -s, --message-size=        Average number of bytes per message. At least 8
                             needed to collect timing data (default: 50)
  -v, --msg-rate-variance=   Variance (seconds squared) of the sample of
                             message rates (default: 0.005)
  -V, --msg-size-variance=   Variance (messages squared) of the sample of
                             message sizes (default: 5)
  -t, --topic-prefix=        Prefix to add to all random topic names for each
                             publisher (default: test/)
  -i, --interval=            Interval (in seconds) between successive broker
                             connection attempts (default: 1)

Input/Output Files:
  -c, --ca-file=             Certificate authority to enable anonymous TLS
                             connection
  -o, --output=              Output file to write detailed pub/sub statistics
                             to (default: stdout)
  -y, --yaml=                Input file with command-line parameters in YAML
                             format. CL options override YAML input

Help Options:
  -h, --help                 Show this help message

The command-line options afford you the flexibility to publish more or fewer messages, at whatever rate you choose.

Alternative Input: YAML

If you do not want to specify all input options on the command-line, you can write a YAML-formatted input file whose keys are the same as the long command-line options shown above. An example file is shown below:

# Sample YAML file for input to mqtt_stresser. The YAML names are the same as
# the command-line flags (without the leading -- or short options)
hostname: somehost
passwd-file: passwd
username: username
password: password
port: 1985
num-publishers: 100
messages-per-second: 100
msg-rate-variance: 1.0
message-size: 100
msg-size-variance: 10
duration: 120
topic-prefix: sometopic/
ca-file: some.crt
output: some.csv

The way input is processed is that YAML files are processed first, and any other command-line arguments are processed second. Because of this order of operations, any command-line argument will override the contents of the YAML file for that particular input variable.