Node.js based express app EXTREMELY slow on ec2 micro instance

Question

Here's the setup:

• ec2 micro instance
• MySQL 5.6
• Redis server
• Node.js (express based app)
• Nginx as reverse front-end proxy.

It's slow. Very slow. I know it's a micro instance and you get what you pay for (considering it's free).

I ended up even using a swap file for MySQL and it's so slow to the point that it's unusable. Should I spin up 2 medium instances (1 for the db/redis and one for the app server)? Keep everything on one and upgrade it to a large instance?

Also, what should I be looking for? More RAM for MySQL and more CPU for the app server? Any input would be extremely helpful (especially those that have used a similar setup in the past).

Answer 1

Keep in mind that EC2 micro instances throttle the cpu - the can surge a bit but if you place consistent cpu load on a micro instance it will throttle down. They are really designed for development - I've used micro instances as web servers before and have paid the price when they throttled down just when the load went up - basically ground to a halt.

As to what you should use you'll really need to assess your own needs based on a combination of benchmarking and analysis on database size, working set size, number of users etc.

That said, if you intend to scale your app at all trying to keep everything on one virtualized server tends not to work well. EC2 currently has many different instance types optimized for different usage scenarios, variously emphasizing cpu, memory, local disk or network capacity. Scaling the node.js/nginx side of your app is very different than MySQL and Redis.

Personally (and it's just my opinion) I'd start with two smalls, MySQL and Redis on one, node and nginx on the other and monitor memory, cpu and disk usage carefully. The great thing about EC2 (or any of the major cloud based virtual instance providers) is the ease with which you can experiment and move to another instance type. To facilitate that I'd definitely use an EBS volume as your database as it makes it very easy to move it later (not to mention backups using volume snapshots for backups).