To set up your PHP installation for multiple nodes, download a single agent from Splunk AppDynamics.

Then follow the instructions in Install the PHP Agent by RPM (for RedHat and CentOSX) and Install the PHP Agent by Shell Script (all other Linux and Mac OS) for instrumenting the agent. Configure the required settings using an app/tier/node configuration that fits one of the applications you are instrumenting. Make sure you configure the required settings listed below.

Then, for each additional application that you want the agent to monitor, add a Splunk AppDynamics configuration with different settings that reflect how you want the performance metrics to be reported in your Splunk AppDynamics model.