I have a basic question about scout that I didn’t find in the help section.

Given a web app on a server that doesn’t use Ruby, what the performance impact of installing not just the Scout Client, but also the Ruby engine as well? Can you give us some numbers so we have a sense of it?

Christian,

We built Scout so that it’s impact on performance would be very small. Here’s the basics:

• In our tests, the Scout client used btw 5-15 MB of memory when running
• The Scout client only runs when it’s executing the plugins (ex: every 30 minutes on the free plan) so it doesn’t use resources when it’s not active.
• The impact on the server load wasn’t detectable

The client is extremely light – most of the work is done by the plugins. You could build a plugin that is extremely intensive – one that requires a lot of libraries maybe – and it will certainly use more resources. So in the end, it’s up to you.

Also note that you can use Scout to monitor itself – you can use the server load plugin and monitor the memory usage of the “ruby” process to get a feel.

Also, if you’re worried about CPU cycles being stolen by Scout, you can always run scout using nice to give it a low priority:

/usr/bin/nice -n 10 /usr/bin/scout

We’ve found the performance impact to be very very low, nonetheless.