Has anyone been brave enough to deploy reseller limits to their production servers?
If so, has it made any difference?
If you actually give individual users too lower a CPU limit individually it uses more CPU due to the added context switching, which is why it's recommended to offer 100% CPU or more per user.
https://en.wikipedia.org/wiki/Context_switchI am sorry but I am confused... Are you saying by allocating less than 100% of CPU dramatically increases overheads of CloudLinux?
That's doesn't even make sense as I heard the hardest Virtualization tech will draw about 5% at "worst" from the bare hardware.
No, the latest version (beta) of CloudLinux allows an admin to place a CPU limit on a reseller so that they may not use more than a permitted amount of CPU in total.
Before there was just the limit per account, but now there is a limit in total!
(further clarification: the sum total of CPU for all the resellers' accounts cannot exceed this limit)
why i can not see this feature on my cloulinux? do they charge extra fee fro this feature?
I am sorry but I am confused... Are you saying by allocating less than 100% of CPU dramatically increases overheads of CloudLinux?
That's doesn't even make sense as I heard the hardest Virtualization tech will draw about 5% at "worst" from the bare hardware.
If you set a really low CPU limit, the machine will spend more CPU time suspending and unsuspending processes than it will executing code.
Remeber CloudLinux isn't about giving small resources per users it's about ensuring users have enough power by stopping abusers taking too much power.
(As well as clearing showing who is using that power)
It's worth noting that before CloudLinux all providers except a couple that had custom kernels / kernel extensions were giving total access to every CPU to every account.If you will set the limit that will be best. Because assigning the unlimited resources will increase the server load. It is best to set the limit. CloudLinux has the option in which you can set the resource limit. It is best for all sites on the server as well as for maintaining the uptime of server.
It's worth noting that before CloudLinux all providers except a couple that had custom kernels / kernel extensions were giving total access to every CPU to every account.
It's not impossible to maintain a server in this fashion - but you'll end up with far less capacity overall if you don't manually keep an eye on CPU usage on a regular and ongoing basis.
One of the things CloudLinux has really helped with is reducing the amount of time providers have to spend auditing usage and working with customers.
Out of many thousands of accounts we only have a few here or there that cross limits and we generally reach out and try to work with them to resolve those issues. These are the same accounts that we would notice and reach out to even without CloudLinux - except they would possibly impact others / the server as a whole for a brief period before we caught it.