The gossip application is an example showing how the Plumtree gossip implementation functions.
gossip is distributed as part of the binary distribution of Apache Tuweni, which you can download from this page
{%highlight bash%} ./gossip --help Usage: [-h] [--sending] [--numberOfMessages=] [--payloadSize=] [--sendInterval=] [-c=] [-l=] [-m=] [-n=] [-r=] [-p[=...]]... --numberOfMessages= Number of messages to publish (load testing) --payloadSize= Size of the random payload to send to other peers (load testing) --sending Whether this peer sends random messages to all other peers (load testing) --sendInterval= Interval to wait in between sending messages in milliseconds (load testing) -c, --config= Configuration file. -h, --help Prints usage prompt -l, --listen= Port to listen on -m, --messageLog= Log file where messages are stored -n, --networkInterface= Network interface to bind to -p, --peer[=...] Static peers list -r, --rpc= RPC port to listen on {%endhighlight%}
You can set up a gossip app to listen with this command: {%highlight bash%} ./gossip -l 9000 -m /tmp/log {%endhighlight%}
In a separate shell, you can send messages to the listener with:
{%highlight bash%} ./gossip -l 9001 -p 127.0.0.1:9000 --sending --payloadSize=32 --numberOfMessages=10 -p tcp://127.0.0.1:9000 --sendInterval=1000 {%endhighlight%}
This will send 10 messages, of 32 random bytes each. Open the file /tmp/log to see them.
You can create more complex scenarios with multiple gossip listeners, showing the path by which gossip circulates across peers.