DemoBench

DemoBench is a standalone desktop application that makes it easy to configure and launch local Corda nodes. It is useful for training sessions, demos or just experimentation.

Downloading

Installers compatible with the latest Corda release can be downloaded from the Corda website.

Running DemoBench

Configuring a Node

Each node must have a unique name to identify it to the network map service. DemoBench will suggest node names, nearest cities and local port numbers to use.

The first node will host the network map service, and we are forcing that node also to be a notary. Hence only notary services will be available to be selected in the Services list. For subsequent nodes you may also select any of Corda’s other built-in services.

Press the Start node button to launch the Corda node with your configuration.

Running Nodes
DemoBench launches each new node in a terminal emulator. The View Database, Launch Explorer and Launch Web Server buttons will all be disabled until the node has finished booting. DemoBench will then display simple statistics about the node such as its cash balance.

It is currently impossible from DemoBench to restart a node that has terminated, e.g. because the user typed “bye” at the node’s shell prompt. However, that node’s data and logs still remain in its directory.

Exiting DemoBench
When you terminate DemoBench, it will automatically shut down any nodes and explorers that it has launched and then exit.
Profiles
You can save the configurations and CorDapps for all of DemoBench’s currently running nodes into a profile, which is a ZIP file with the following layout, e.g.:
notary/
    node.conf
    plugins/
banka/
    node.conf
    plugins/
bankb/
    node.conf
    plugins/
        example-cordapp.jar
...
When DemoBench reloads this profile it will close any nodes that it is currently running and then launch these new nodes instead. All nodes will be created with a brand new database. Note that the node.conf files within each profile are JSON/HOCON format, and so can be extracted and edited as required.

DemoBench writes a log file to the following location:

MacOSX/Linux $HOME/demobench/demobench.log
Windows %USERPROFILE%\demobench\demobench.log

Building the Installers

There are three scripts in the tools/demobench directory:

  1. package-demobench-exe.bat (Windows)
  2. package-demobench-dmg.sh (MacOS)
  3. package-demobench-rpm.sh (Fedora/Linux)

Each script can only be run on its target platform, and each expects the platform’s installation tools already to be available.

  1. Windows: Inno Setup 5+
  2. MacOS: The packaging tools should be available automatically. The DMG contents will also be signed if the packager finds a valid Developer ID Application certificate on the keyring. You can create such a certificate by generating a Certificate Signing Request and then asking your local “Apple team agent” to upload it to the Apple Developer portal. (See here.)
  3. Fedora/Linux: rpm-build packages.

You will also need to define the environment variable JAVA_HOME to point to the same JDK that you use to run Gradle. The installer will be written to the tools/demobench/build/javapackage/bundles directory, and can be installed like any other application for your platform.

Developer Notes

Developers wishing to run DemoBench without building a new installer each time can install it locally using Gradle:

$ gradlew tools:demobench:installDist
$ cd tools/demobench/build/install/demobench
$ bin/demobench

Unfortunately, DemoBench’s $CLASSPATH may be too long for the Windows shell . In which case you can still run DemoBench as follows:

> java -Djava.util.logging.config.class=net.corda.demobench.config.LoggingConfig -jar lib/demobench-$version.jar

While DemoBench can be executed within an IDE, it would be up to the Developer to install all of its runtime dependencies beforehand into their correct locations relative to the value of the user.dir system property (i.e. the current working directory of the JVM):

corda/
    corda.jar
    corda-webserver.jar
explorer/
    node-explorer.jar
plugins/
    bank-of-corda.jar