Pre-requisite

Install voltdb first. Refer to https://github.com/DBOS-project/dbos-scheduler/ on how to install VoltDB.

AccountTransfer Example and Benchmark

AccountTransfer is a small VoltDB application that measures VoltDB throughput under varying portions of single-partiton and multi-partition transactions.

Variations to Try

• Change the disk persistence settings using a deployment.xml file. Try synchronous and asynchronous persistence. Try the app without persistence at all.
• Try with different replication settings.
• Change the number of contested keys by editing the run.sh file.
• Vary the mixture of single and multi partiton transactions
• Alter the default number (currently 8) of partition replicas per host using a deployment.xml file.

A more complex version of this app might populate the base table with billions of rows, but send 99% of updates to a single row. That might be a fun experiment for someone looking to learn VoltDB.

Quickstart

Make sure "bin" inside the VoltDB kit is in your PATH. Then open a shell and go to the examples/contentionmark directory, then execute the following commands to start the database:

voltdb init
voltdb start

Wait until you see "Server completed initialization." Open a new shell in the same directory and run the following to load the schema:

sqlcmd < ddl.sql

In the same shell, run the following script to preload some data and run the demo client application:

./run.sh client

You can stop the server or running client at any time with Ctrl-c or SIGINT. Of course VoltDB can also run in the background using the -B option, in which case you can stop it with the voltadmin shutdown command.

Note that the downloaded VoltDB kits include pre-compiled stored procedures and client code as jarfiles. To run the example from a source build, it may be necessary to compile the Java source code by typing "run.sh jars" before step 3 above. Note that this step requires a full Java JDK.

Using the run.sh script

VoltDB examples come with a run.sh shell script that simplifies compiling and running the example client application and other parts of the examples.

• run.sh : start the server
• run.sh server : start the server
• run.sh init : compile stored procedures and load the schema and stored procedures
• run.sh jars : compile all Java clients and stored procedures into two Java jarfiles
• run.sh client : start the client, more than 1 client is permitted
• run.sh clean : remove compilation and runtime artifacts
• run.sh cleanall : remove compilation and runtime artifacts and the two included jarfiles

If you change the client or procedure Java code, you must recompile the jars by deleting them in the shell or using ./run.sh jars.

Client Behavior Options

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

Speed & Duration:

--displayinterval=5           (seconds between status reports)
--warmup=5                    (how long to warm up before measuring
                               benchmark performance.)
--duration=120                (benchmark duration in seconds)
--ratelimit=20000             (run up to this rate of requests/second)

Cluster Info:

--servers=$SERVERS            (host(s) client connect to, e.g.
                               =localhost
                               =localhost:21212
                               =volt9a,volt9b,volt9c
                               =foo.example.com:21212,bar.example.com:21212)

Parameters Affecting Simulation:

--accounts=1000                    (number of accounts to contend for)
--spratio=1                        (percentage of single-partition transactions)

Customizing this Example

See the "deployment-examples" directory within the "examples" directory for ways to alter the default single-node, no authorization deployment style of the examples. There are readme files and example deployment XML files for different clustering, authorization, export, logging and persistence settings.