Edge Documentation

Multiple instances of AppBoard can be configured to run on the same system. This article details some of the considerations to have this work correctly.

Why Multiple Instances?

The following are some sample cases where you may want to install more than one instance of AppBoard on the same server:

• Testing - The test team needs to have multiple versions of the system available so they can validate the functionality and features against one another.
• Development - A developer is working on multiple AppBoard development projects at the same time.
• Staging - A production and dev system are both running on the production server. They can be swapped, for example, to make the dev system become the production system after validation is complete and certified.
• Demos - Multiple demo systems can be created and provided at the same time for review.
• Multi-homed server - have different copies of AppBoard running for different target networks.

Configuration

Refer to the Runtime Options page for a complete listing of options, but for the purposes of running multiple copies of AppBoard on the same server the following are critical:

Option	Description
HTTP_PORT	Each instance will need to listen on a different port.
SHUTDOWN_PORT	Each instance will need it's own shutdown port.
HTTP_ADDRESS	(optional) for multi-homed systems, restrict AppBoard to listen only on a specific IP address.

Review the following items to make sure each of the AppBoard instances is configured properly.

Port Configuration

When installing more than one instance of AppBoard on the same server, the most important item to configure is the ports. There are two ports used by each instance, and they must be unique for each system. If you start an AppBoard system, and it tries to use a port that is already in use, you will receive a JVM Bind Error, and the system will not start.

Refer to the Runtime Options page to make changes, specifically the HTTP_PORT and SHUTDOWN_PORT settings.

Memory Configuration

When running multiple AppBoard instances on the same server, the system administrator should consider the memory capacity of the server. If the System Requirements recommend 2 GB of RAM for AppBoard, it would be advisable for example to have 4 GB of RAM if two instances will be running on the same server.

One way to limit the memory footprint of AppBoard is in the Tomcat memory configuration settings. For a dev or demo instance, you can typically lower the Java Virtual Machine (JVM) maximum heap size (-Xmx JVM parameter) to a low setting such as -Xmx512m. without any noticeable change in performance.

Database

If you are using the default AppBoard database settings and the embedded local AppBoard H2 database, no special configuration is required to run multiple instances on the same server. Each instance ill use it's own database.

If your system is configured to access an external database, such as Oracle or MySQL, then care must be taken. If you have two systems running locally that are accessing the same database, unpredictable results may occur. For example, if you add a test User on the dev instance, and this is connected to the same database as the production instance, the test User will also appear in the production instance.

Configuring Dual-NIC Deployments

In some cases, you may want to run two AppBoard applications on the same server that bind to different IP addresses. For instructions on this, see Binding AppBoard/enPortal to a specific IP/Interface.