Can Code Igniter handle a large load?

[eluser]kaosweaver[/eluser]
I'd like to hear from people who've actually had loads like we've had (or more) to see if the load is easily handled by CI.

Our desire is to make sure it can handle around 40,000 people an hour with 90% of that traffic coming within the first 10-15m, each person hitting on average 5 pages (~200,000 page views).

We're using APC cache where we can, although we do have some direct DB access that is updated constantly, our dedicated server has:
8 CPUs
32 GB RAM (6 of which is devoted to the APC cache)
We also have a dedicated database server with the same stats (8 CPUs, 32 GB ram)
And a dedicated server for static resources (like images, lots and lots of images) which has 2cpus and 8GB of ram.

Our current traffic is roughly 2/3rds of the above, so if you've got experience with it running around there successfully (and hopefully with headroom), I'd like to know as well.

I appreciate your input.

[eluser]WanWizard[/eluser]
The traffic an application can handle greatly depends on the application, and only for a very small part on the underlying framework.

One badly written query will already cost you more processing time then the time spent in the framework code.

I run applications with more traffic that talk to a MySQL running in a 2Gb 2vCPU VM without problems. But these are specifically written for high-loads, and highly optimized. I've also seen application that were written so badly that they crumbled under very little load.

So I think it's going to be a challenge to get any decent figures that might be applicable to your specific situation.

[eluser]kaosweaver[/eluser]
Thanks for the notes - I do understand the complexity of being able to guess if it will work for me, I'm more looking to the capabilities of CI that people have seen or worked with. If the code is inadequate, we'll have to optimize, but if CI can't run with it, then no level of optimization would work.

[eluser]WanWizard[/eluser]
I would not expect any issues with the framework. CI is pretty basic in functionality, and therefore quite light-weight.

If there are things that you might possibly "blame" on the framework, it is that because of the rather basic functionality, it doesn't support features required in such setups (like better and granular caching, memcached/redis support, etc) which requires you to use third party code that might not be as well thought out as the core code itself.

The occasions where we decided not to use CI all were related to this. To get all functionality the app needed we ended up bolting a ton of third party and custom made stuff to it and extended a lot of the core classes, leading to a bloated application that required lots of memory and didn't perform well.

That didn't have anything to do with the framework as such, but with the fact that it wasn't the right tool for the job.