Hi
The big obstacle in estimating infrastructure for large Moodle deployments is that, every deployment is different - in terms of the infrastructure and the architecture as well as the user loads and patterns. In your case we know that it is a) about a single server - a large VPS b) you have targets on N, N being the number of candidates you can send to a synchronous exam (on Quiz module). Well, you said something about SCORM - still in the subject line. I think, you were forced to forget it, for the sake of simplicity.
You were lucky. Emilio could give you custom tailored and exact (with numbers) advice, as he has done in the past in this forum and also presented in Moodle Moots. I've added his post to my collection, suggest adding it to the Performance documentation as well. Rather than reiterating those topics here are some observations from an administrative point of view.
About the timing of the exams: You talk of a world-wide audience. Do they belong to the same institution? If not, it is highly unlikely that synchronous exams of different institutions will start exactly at the same universal time.
About the readiness of the server: Do you expect the N candidate exam will be conducted the day you deploy the server? What I want to point out is that deploying a Moodle server is fundamentally different from building a fortress or a battleship. a) It won't be stormed the day it goes in operation. b) Even if that happens, you can still make corrections. In other words, a gradual start and corrections as you go on are (luckily) possible.
My interest is not primarily getting big absolute numbers of load, rather getting the maximum load from given resources resp. servicing a given load with minimum resources. Throughout the years I have observed people (including myself) overestimate the future load resp. astronomically overestimate the infrastructure necessary. OK, some have the money. But I plead for the environment, the time of "My car, my patrol" is long over.
The big obstacle in estimating infrastructure for large Moodle deployments is that, every deployment is different - in terms of the infrastructure and the architecture as well as the user loads and patterns. In your case we know that it is a) about a single server - a large VPS b) you have targets on N, N being the number of candidates you can send to a synchronous exam (on Quiz module). Well, you said something about SCORM - still in the subject line. I think, you were forced to forget it, for the sake of simplicity.
You were lucky. Emilio could give you custom tailored and exact (with numbers) advice, as he has done in the past in this forum and also presented in Moodle Moots. I've added his post to my collection, suggest adding it to the Performance documentation as well. Rather than reiterating those topics here are some observations from an administrative point of view.
About the timing of the exams: You talk of a world-wide audience. Do they belong to the same institution? If not, it is highly unlikely that synchronous exams of different institutions will start exactly at the same universal time.
About the readiness of the server: Do you expect the N candidate exam will be conducted the day you deploy the server? What I want to point out is that deploying a Moodle server is fundamentally different from building a fortress or a battleship. a) It won't be stormed the day it goes in operation. b) Even if that happens, you can still make corrections. In other words, a gradual start and corrections as you go on are (luckily) possible.
My interest is not primarily getting big absolute numbers of load, rather getting the maximum load from given resources resp. servicing a given load with minimum resources. Throughout the years I have observed people (including myself) overestimate the future load resp. astronomically overestimate the infrastructure necessary. OK, some have the money. But I plead for the environment, the time of "My car, my patrol" is long over.
Don't read between the lines: Nowhere I say, you are wasting resources. In fact, you made a favourable decision by going for VPS over dedicated hardware (which would idle, still burn energy, until the load arrives). My point at the beginning with fortresses and battleships is that singe or dual (web+DB) Moodle servers are flexible, you can shift them easily, once you've got the experience. That is exactly what I advised more than once, start in the available/existing infrastructure, monitor deeply, once signs of overloading appears, move to the next level. Not to commit to a five year plan NOW - although it is technically challenging and therefore interesting. You can have the same fun by squeezing smaller machines. Do you need a Porsche for the kick of speed, when downhill on a racing bicycle would do?
