After you have created hosting plans in your reseller account, you should additionally configure LVE Resource Limits for those packages.
What are LVE Resource Limits?
In addition to the standard inclusions of a hosting account, such as Disk Quota and Email Accounts, you can also configure limits on the following resources:
- SPEED (CPU): The maximum amount of CPU that an account can use at any one time. This is just a throttle, so it won't cause any errors to appear, but if it's reached, processes will take longer to run. It is represented as a percentage of a single CPU core, so 100% = 1 CPU core.
- PMEM (Physical Memory): The maximum amount of memory that an account can allocate at any one time. This is a hard limit, so if it is reached, any additional requests that try to use memory will be denied; if it's a web page request, the visitor will see a 503 or 508 "Resource Limit Reached" error message.
- EP (Entry Processes): The maximum number of concurrent Apache (website) requests that can be running. It would be very unusual to have more than a couple of concurrent requests, except when the request is slow, such as when there is no caching in place. The default setting of "20" should be plenty, but a dynamic web application that makes lots of uncached AJAX requests might need more. If it's an otherwise low-traffic website, and this limit is being reached, look at possible problems with the website itself (e.g. no caching). Be aware that each request uses memory, so PMEM and EP should be increased in relative terms.
- NPROC (Number of Processes): The maximum number of concurrent system processes that can be running. Typically a dynamic website will utilise 1 system process for each (PHP) web page request, but it's possible for a process to spawn child processes, so to be safe, always have this number higher than EP. When considering PMEM, look at both EP and NPROC, assume that a PHP process will use 40-100MB of memory, therefore 20 processes multiplied by average 60MB of memory could use 1.2GB memory usage.
- IO (Disk Throughput): Not limited
- IOPS (Disk Operations): The number of read and write disk operations per second. The default of 1024 should be reasonable for all types of web hosting account.
How do I set LVE Resource Limits for my hosting packages?
In WHM, go to CloudLinux Manager > Packages, then click the pencil icon beside each package you have configured.
What settings do you recommend?
Here are some suggested starting points:
- A low-cost, low-traffic website plan should be satisfied by 50% CPU, 1GB PMEM, 1024 IOPS, 20 EP, 40 NPROC
- A WordPress website, especially one with "heavy" plugins such as eCommerce or visual editors, will often have lots of uncached AJAX calls, so higher limits are recommended; start with 100% CPU, 2GB PMEM, 1024 IOPS, 20 EP, 40 NPROC
- A medium-traffic website, or a web application where many requests are uncached, would benefit from 200% CPU, 4GB PMEM, 4096 IOPS, 80 EP, 160 NPROC
Can I override individual accounts?
Yes. In CloudLinux Manager > Users, you can edit an invididual user and override their limits to be different to their package. This can be useful as a temporary fix while an underlying problem is being investigated or if the website is receiving unexpected traffic.
How do I monitor usage?
In WHM, go to CloudLinux Manager > Statistics or Users, and you'll be able to see the resource usage history of each account, and if any "faults" were hit (where a limit was reached).
Based on this, you might consider (a) upgrading accounts to plans with more resources, (b) investigating any problems with the website itself, or (c) revising your package resource limits upwards if many users on the same package are hitting limits.
How high can I set the limits?
Your reseller account has its own aggregate LVE Resource Limits which are defined by the reseller plan you have with us.
Generally, you want to ensure that individual limits are well under your reseller limits, but it's safe to "oversell" this, jsut as you do with Disk Quotas, because it's unlikely every user will reach its limit at the same time.
You can set individual account limits up to and equal to your own reseller account limits, but if multiple accounts do this, there is a higher possibility that individual users are at risk of not receiving the full benefit of the resources you have allocated to them.
