I work for a digital agency, where we design, build and host websites for our (local) clients. Currently, we have approx. 80-90 sites scattered on 11 VPS instances. 99% of those sites is WordPress and 80% is (very-) low traffic. We have a few that have a constant (and slowly growing) flow of visitors. There is also one, that is a seasonal: for 11 months the site is as good as dead, but then when it "wakes up", it generates quite a lot of traffic (ticket sales and check-ins).
In the coming weeks / months we will be migrating a new client, whose website generates more traffic in one day, than 50% our least busy websites, combined, in a month (currently approx. 10 GB / day, but we're working on optimising the site, prior to migrating)
That site currently sits on a VPS with 2x vCPU's (Intel Xeon E5-2650 v3 @ 2.30GHz), 4 GB memory and current consumption is:
load average: 0.74, 1.30, 1.41
KiB Mem : 4194304 total, 1443792 free, 1534936 used, 1215576 buff/cache
As for our servers: most of them is a 4x vCPU / 8GB RAM and although each one is being backed up on a daily basis, there is no failover / redundancy in place.
As we're looking to "up our game" and provide more failure-resistant service, I have to admit, that while up until now I knew my way around and could solve most of the issues we had with our servers - when it comes to scaling and the like - I am lost.
I do feel that 11x VPS is most likely an overkill, and those resources could have been organised in a much better way, but this is how things were here when I joined a year ago, and up until now there was no "need" and/or time to think about alternatives / improvements
So with this "story" I would like to get an advice on what solutions should we be setting our eyes at, to benefit us most? How to put the resources we have to a best use? Or should we be rather looking for a Dedicated Server?
Personally, I was thinking about a following setup:
- two larger web-serwers behind a load balancer
- two larger web-serwers behind a load balancer + one DB server
and to cut the load even further, both web-serwers with CDN
any help would be greatly appreciated.