VoltDB Example App: Metro

Use Case

This application performs high velocity transaction processing for metro cards. These transactions include:

• Card generation (during the initialization)
• Card Swipes (during the benchmark)

Code organization

The code is divided into projects:

• "db": the database project, which contains the schema, stored procedures and other configurations that are compiled into a catalog and run in a VoltDB database.
  
• "client": a java client that loads a set of cards and then generates random card transactions a high velocity to simulate card activity.
• "web": a web dashboard client (static html page with dynamic content)

See below for instructions on running these applications. For any questions, please contact fieldengineering@voltdb.com.

Pre-requisites

Before running these scripts you need to have VoltDB 4.0 (Enterprise or Community) or later installed, and you should add the voltdb-$(VERSION)/bin directory to your PATH environment variable, for example:

export PATH="$PATH:$HOME/voltdb-ent-4.0.2/bin"

Demo Instructions

1. Start the web server

   ./run.sh start_web

2. Start the database and client

   ./run.sh demo

3. Open a web browser to http://hostname:8081

4. To stop the demo:

Stop the client (if it hasn't already completed)

Ctrl-C

Stop the database

voltadmin shutdown

Stop the web server

./run.sh stop_web

Options

You can control various characteristics of the demo by modifying the parameters passed into the InvestmentBenchmark java application in the "client" function of the run.sh script.

Speed & Duration:

--duration=120                (benchmark duration in seconds)
--autotune=true               (true = ignore rate limit, run at max throughput until latency is impacted)
                              (false = run at the specified rate limit)
--ratelimit=20000             (when autotune=false, run up to this rate of requests/second)

Metadata volumes and ratios:

--cardcount=500000            (number of metro cards created)

Instructions for running on a cluster

Before running this demo on a cluster, make the following changes:

1. On each server, edit the run.sh file to set the HOST variable to the name of the first server in the cluster:

   HOST=voltserver01

2. On each server, edit db/deployment.xml to change hostcount from 1 to the actual number of servers:

3. On each server, start the database

   ./run.sh server

4. On one server, Edit the run.sh script to set the SERVERS variable to a comma-separated list of the servers in the cluster

   SERVERS=voltserver01,voltserver02,voltserver03

5. Run the client script:

   ./run.sh client