Capacities on Load-balancer & Web Servers? Bandwidth + Performance

Question

(I'm on DigitalOcean) Then I have a very simple scenario for my WEBSITE.

• Now having 3000 concurrent hits every minutes. (For example)
• Currently it is directly on 1 only single Apache Server.
• The website CAN NOT be Cached. (for some sensitive reason)

Then i am thinking for simply advanced setup, like:

• 1x Software Load Balancer (e.g, Nginx)
• 3x Apache as Web Servers .. at behind LB.

Then suddenly my simple (but BIG) questions are:

• Load Balancer or Web Servers. Which ones should have better CAPACITIES, in terms of BANDWIDTH and PERFOMANCE.

Lets say LB redirects 1000 connections to each Web Servers. Does it mean:

1. The LB still need to consume 3000 Traffic Bandwidth IN+OUT?
2. Each WebServer still need to consume 1000 Traffic Bandwidth IN+OUT?
3. LB should have big PROCESSING performance? Or, the WebServers?

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To be more dummy ..

Something like ..

• Do i need to buy $80 / month for LB Droplet (and, leave $20 Droplets for WebServers)?
• (or) Do i need to buy $40 / month 3x WebServer Droplets (and, leave $10 Droplet for LB)?
• (or) All the same?

Please kindly help me adviced since i'm very new in setting up own LB environment.
Thank you.

Answer 1

1. Yes. But, usually, that "internal" traffic is free.
2. Yes.
3. Nginx as LB is consuming very tiny amount of resources. All performance resources should be given to Apache servers. But it will use all "outgoing" bandwidth.

Also, Nginx on LB can be used as web server for serving static content (if you don't have too much of it)