Should I use a dedicated network channel between the database and the application server?

Question

Should I use a dedicated network channel between the database and the application server?

...or...

Connecting both in the switch along with all other computer nodes makes no diference at all?

The matter is performance!

Answer 1

It all depends on the throughput needs of your application. If you absolutely need the lowest latency possible, then it would make sense to optimize the routes. Aside from hugely scalable software, I would argue that this is rarely needed and you can just connect everything in a generic fashion.

Answer 2

It depends on your non-functional requirements. Assuming the NICs are running at the same rate, keeping the database traffic away from the front-end traffic can only be a good thing from a bandwidth perspective - if bandwidth is an issue.

Far more significant is that security is improved by keeping the front-side and data-sides on different networks as the only way to gain direct access to the database is to compromise the application server.

Answer 3

Using the shared switch could give increased latency, especially if the switch is busy. Also, you may be able to hook up a faster dedicated network channel (e.g. gigabit ethernet, if your switch is 100Mbit). Whether any of this is worth doing or not depends on your application though.

You may also want to use a dedicated channel for increased security (making your database server less accessible).