Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We have a server system that currently consists of 1 Apache server that is attached to a load balancer and one MySQL server that is by itself. Both servers are AWS Micro Instances.

Everything is running smoothly so far, but I want to be smartly pro-active in upgrading the servers. I have been running "top" to see the CPU and memory usage, but that won't do me much good if I don't know when I should take action.


Currently the CPU usage sits around 0.0 - 0.7% but can jump up to 60% for an instant.

The memory reads: 608732k total, 601556k used, 7176k free, 38768k buffers


The CPU is between 0.0 - 1.0 % at almost all times

The memory reads: 608732k total, 540772k used, 67960k free, 155896k buffers

So... there is more free memory on the Apache server. That is great, but what can I watch for as an indication that I should be upgrading? With the Apache server I can add more instances to the Load Balancer in a pinch, but I don't want to get caught with the MySQL server.

Any insights you have would be greatly appreciated.

share|improve this question
up vote 0 down vote accepted

First, install a package like sysstat to monitor the machine's load. You are interested mostly in peak loads (say over a week/month). If the load approaches the machine's capacity, it is time to get a bigger one/a sibling behind load balancing. A trend over a longish period tells you when it will be time to upgrade.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.