Example Simulant Test

This module has a complete test harness built with Simulant. It simulates a shopper interacting with an ecommerce system. The parts are designed to be easy to learn.

You can interact with the simulation via a command-line interface or a REPL.

This depends on Datomic Free. With a minor change to project.clj, it will work with Datomic Pro as well.

Everything interesting is under the simtest directory. You should cd into it right away.

One-time Setup

Before we can get started, we need to set up some fake item and category data. In a real implementation, you would get this from the system under test. For our purposes, a big pile of fake data will suffice.

1. Generate seed data lein run -m create-data

Walkthrough

1. Start Datomic with scripts/start-transactor.sh
2. Install the schema lein run install-schema
3. Make a model lein run make-model
4. Make a different model lein run make-model -m "Another model"
5. See the models lein run list-models
6. View the model's parameters lein run list-model-parameters
7. Reduce the abandon rate lein run set-model-parameter abandon-rate 8
8. View the new parameters lein run list-model-parameters
9. Make an activity stream lein run make-activity
10. View the activity stream lein run list-activities

Introducing the Parts

Basic schema

Some one-time setup is needed. simtest.database has a simple migrations framework to install the schema. The schema definitions are in resources/simulant/schema.edn and resources/simtest.edn

The Model

The model is expressed in simtest.model. There are three parts to the model itself:

1. State transitions, represented as shopper-transitions. This function returns a sparse Markov matrix that we use to create a random walk through the commerce system.
2. Control parameters that adjust various probabilities. These are read from a model entity in the database. They change the Markov transition probabilities. They also affect how heavily traffic will focus on "hot" items and categories.
3. Category and item data. In a full system, this would either be extracted from the target system or pushed into it at simulation start. We've got a data generator that spoofs up a pile of identifiers. You should have run this as part of the one-time setup. If not, please go back and do that now.

Generator

The generator is cleverly named simtest.generator. It divides roughly into three sections.

1. Creating an activity stream for a single agent, based on the model.
2. Building a population of agents and their activity streams.
3. The command line interface functions and their helpers.

Execution/Capture

Not implemented yet.

Validation

Not implemented yet.

License

Copyright © 2014-2015 Cognitect, Inc.

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.