Hi

I am looking for some advice about hosting Limesurvey on Amazon Web Services (AWS) EC2, as I need to select an instance type to host an upcoming survey.

I have enough technical knowledge to install and use Limesurvey on a single instance (using Elastic Block Storage), but I am not a server or database expert.

I expect that the number of participants filling in my survey at the same time will usually be pretty low (no more than about 30), but from time to time there may be surges in traffic (eg 300 people trying to fill in the survey at once). I’d like to choose an AWS instance type that will be able to cope with surges in traffic.

I searched the forums and some people mentioned they have had success using hosing limesurvey using AWS ‘general purpose’ instances (eg m3.medium, m3.large, m3.xlarge). Amazon also sells ‘compute optimized’ (extra vCPUs) and ‘memory optimized’ (extra RAM) instances.

Below is a list of instance types, ordered from cheapest to most expensive.
Prices are for Asia Pacific (Sydney) region, as my participants are all Australian.

m3.medium (1vCPU, 3.75GB RAM), 9.8c/hr (general purpose instance)
c3.large (2vCPU, 3.75GB RAM), 13.2c/hr (compute optimized instance)
m3.large (2vCPU, 7.5GB memory), 19.6c/hr (general purpose instance)
r3.large (2vCPU, 15GB RAM), 21c/hr (memory optimized)
m3.xlarge (4vCPU, 15GB RAM), 39.2c/hr (general purpose)

Which instance type would you recommend I use?
It needs to be big enough to deal with surges in traffic but not so large that I am wasting money.

As an aside, I’ve read a bit about auto-scaling and multiple instances on AWS, but I think setting this up for limesurvey is beyond my technical expertise. I have no idea how if I had multiple instances of limesurvey I would get the data stored in one central database (using Amazon’s RDS???). This is why I’m looking at a single instance solution using EBS.

Thanks in advance for your help!

David

Have you considered using LimeService? They can handle any load.

I did but I didn't think they'd have Australian servers (all participants in this study are Australian).

I don't think it matters where the server is. I have clients using LimeService from Canada - no problem.

Well, there might be some minor delays when the server is not located close to the target audience. For survey taking this is usually not so much of a problem because the speed is often more dependent on how quick the server (e.g. processor, HDD vs. SSD) or the database connection is.

For applications like VOIP or video conferences there should be a much stronger impact.

tpartner, it is because LimeService has a server in Canada
Unfortunately not in Australia - yet.