Not only can you scale based on OS-level metrics like CPU and RAM, but you can also define your own metrics. For example, social games may want to scale according to DailyAverageUsers while datastores may prefer ReqSec. Just tell Scalr where to find the custom metric, whether to read or execute the file, and (when it collects the values from all your servers) whether to compare the average or the sum with the thresholds you set. Auto-scaling has never been easier.
Once you create your custom scaling metric, you can apply it to any component of your farm.
You can set multiple rules for auto-scaling. If any of them warrant upscaling, Scalr adds more servers. When you want to downscale, Scalr stops sending traffic to a server and gives it 5 minutes to run any lingering jobs before shutting it down.
