README.md

Validated Streams basic sample

Prerequisites:

• Docker with docker-compose (Podman with podman-compose should work too)
• grpcurl
• pumba for the network resilience example
  • When downloading the pumba binary from releases, ensure that the "pumba" command is accessible in your system's PATH.

1. Witnessing events:

   We have set up a demonstration of a private chain comprised of four nodes (hence, the minimum number of nodes required to witness an event is 3 nodes) and a client that sends random events to them. Running the example:

   1. Build the docker image of a validated streams node (this might take a while the first time)

      docker build -t comradecoop/validated-streams .

   2. Start the example network:

      ./run-example.sh start

      (pass --podman to use podman-compose)
   3. Start an example trusted client witnessing a few thousand events to the example network:

      ./run-example.sh witness

   4. (in another shell) Listen for validated events:

      ./run-example.sh validated

   5. To stop the network:

      ./run-example.sh stop

   Alternatively, use the combined run command directly instead of steps 2-5:

   ./run-example.sh build
   ./run-example.sh run

2. Network resilience testing:

   The following example applies packet loss, frequent crash-recovery, and delayed packets to emulate challenging and poor network conditions. It tests the behavior and resilience of validators within the network under these adverse scenarios.

   ./run-example.sh disturb
   

Architecture

In the basic example, events are witnessed directly from the test script. The script acts as a trusted client and connects to all nodes simultaneously. As such, this example doubles as a demonstration of the danger of exposing the trusted client endpoint to the public - it allows third parties to validate any event they might wish. That's why in a more realistic scenario (e.g. one of the other samples), each validator would run it's own trusted client.