QCI Resource Level
QCI stands for Quality of Service Class Identifier and is a way to put resource allocation into context when compared to other users competing for those same resources.
Resources such as CPU, Memory, Database Process Usage, and Disk I/O Usage are weighted according to a QCI scale. The lower a QCI number is, the higher priority it has when competing for resources.
A lower QCI number means higher priority and you're less likely to run up against resource limitations.
A higher QCI number means lower priority and you may have to wait for higher priority accounts to complete their tasks with any given resource before your task can run.
Why do you not just use hard resource limits?Because resource usage is always changing. Both in terms of what hardware a server is built on and what typical web applications come to demand. It wasn't that long ago that web hosting servers came standard with 16GB of RAM. Now 32GB, 64GB, 128GB - even more - is commonplace. Website design used to be done with pure HTML or simple WordPress designs that did not demand high CPU or Memory usage, but now there are all kinds of WordPress plugins that focus on website design that take more and more CPU and Memory. The QCI scale allows us to fit resource allocation into what hardware a server has and what typical web hosting has evolved to at any point in time.
Can you define what limits are imposed at a particular QCI Resource Level?
No. QCI Resource Levels are not limits per se. Usage is measured within the context of what resources a server can provide and compared against all of the other users on a server. Hard limits create issues when a momentary burst is required, for whatever reason. For example, if your website experiences a massive influx of visitors and consumes 8GB of memory between 7:30AM and 7:40AM and the rest of the day memory consumption is well under 1GB. Now compare that to another website that is consuming 4GB from 10AM to 10PM. Which website is creating more of a strain on the server? Even though your website had an instance that consumed the most memory, the other website consistently used a high amount of memory over a longer period of time. By utilizing QCI, your website is not affected by its momentary need for more memory, but the other website may experience allocation issues depending on what QCI level it is at.
What role does the Cloud play in QCI Resource Levels?
AMS has developed a streamlined account migration system that allows us to treat each web hosting account as its own entity. Together with our network of servers spread all over the world with various hardware specifications, this allows us to freely move accounts from server to server within our network with little to no downtime for our clients' websites. This allows us to reallocate accounts based on their resource usage and minimize the effect of high resource usage accounts on other accounts on a server. It's like having all the benefits of a Cloud infrastructure but within the pricing model of shared web hosting. It is the best of both worlds.
What QCI Resource Level do I need?
This is a difficult question for us to answer because we don't know the nature of your website and what you expect to do with it. If the purpose of your website is to just display information with very little interaction required by the website visitors, often QCI Resource Levels between 6 and 9 function just fine. Generally, a website that is just displaying information doesn't perform a lot of computation on the backend before displaying the information in a visitor's browser. But having said that, this also depends on just how the website is coded. A WordPress website with heavy plugin usage may be performing more computations and holding on to more resources as it compiles the code to display to a visitor's web browser.
If your website requires more interaction - such as an Ecommerce website - it's probably going to use more resources as it compiles all of that information during its interaction with the website's visitors. This may require a QCI Resource Level between 3 and 5, again, just depending on how the website is coded and how that relates to available server resources.
One thing to note, QCI Resource Levels of 1, 2, and 10 are rarely used. These bookend levels allow us to build in a cushion for our high resource usage clients. When you start needing QCI Resource Levels of 1 or 2 it starts to become more cost effective to consider upgrading to a VPS, VDS, or fully dedicated server. Think of QCI Resource Levels 1, 2, and 10 as being reserved for special cases.