New Relic can be an excellent diagnosis tool on development stores and non-production environments. It is natively supported by MageStack and can be enabled by a member of our support team. In order for us to enable New Relic, we simply need two pieces of information from you; the license key and the desired application name.
You do not need to install the New Relic daemon in the access server, as it runs wholly on the web server.
By virtue of the way New Relic works (the PHP module and server-side daemon), it can add overhead to page load times. In a production environment this impact can be considerable, adding anywhere between 0.1s to 2s to TTFB and similar for page render.
We recommend that if New Relic is required, that a standalone web node with a reduced sample of traffic (eg. 5%) runs New Relic, leaving the remainder of the stack to operate without. This will give an insight into New Relic statistics, whilst only impacting 5% of your customers (versus 100%).
Contact a member of the support team to discuss your needs so that we can explain how you can achieve them through MageStack alone without requiring a third party service.