newb question: what does resource hog mean?

[jaguser]

Hello admin and forum members,

I am trying to determine the best VPS configuration to purchase. I have a couple of long standing shared accounts with jag. One account is just for development purpose, and one is the main one. My traffic is not that high for now because it is mostly static. But I have notice that my sites have been very slow recently and I want some guarantee speed. I am looking toward the freedom VPS plan.

I have read that cpanel is a resource hog. What does it mean? Does it effect the CPU or the bandwidth speed? (I think if the cpu resource is low, it will take longer to process and output codes, and so it will look like the bandwidth speed is slowed)

Does it mean that what I log into cpanel, the system will slow down and my sites will also be slowed down?

If I were to host multiple sites and I (or other people) log into cpanels of those sites at once, would it cause the sites to unable to load for visitors?

Also, does cpanel run in the background constantly, if no one is logged in or using cpanel, would it still be running in the background and using CPU resources?

Also, is it possible to request multiple control systems to be installed for users to try out?

[AlexKall]

Resourse hog means that Cpanel uses a bit more memory then some of the other controlpanels. Thats why it has a minimum requirement of 256 mb memory on the host, this means that you can't run Cpanel of Discovery plan (unless you opt for the 128 extra memory).

I know that Plesk is opted to run 100 domains one 256 memory, so a few customers shouldnt do much difference, not on Cpanel either.

[rainboy]

As AlexKall said, cpanel is just a bit larger as others, but also has loads of options to make it all easier for your customers.

Cpanel/WHM is a system, so it keeps running on the background, under its own webserver daemon. (thats why cpanel runs on different ports as port 80)

If your server has enough resources (where memory is a very important one) cpanel works very well.

Multiple config panels to try out ? i think thats impossible, as cpanel/whm for example is not just a config panel, but a complete way of how to setup a server.

You can however look at the different websites of these config-panels and try a test to see how they look like.

I did choose to stick with one control-panel on all my servers, so i dont have to learn all the differences.

Good luck with finding your control-panel to use.

Kindest regards,
Patrick

[jaguser]

Thanks for the answers above, but I am still not sure what they mean in practical terms. Can someone clarify?

For example:
If you compare the 256mb freedom plan vps, and you put 10 sites with 5000 visitors per day on each, what kind of differences can be seen in performance between the cpanel vs interworx setups? Is the difference observed only by the admins when they log into cpanel? Or the difference is observed by the visitors?

If you compare the 256mb vs 128mb plans running interworx, where is the differences in performance seen? is it seen by the admin and/or visitors?

Thanks.

[rainboy]

jaguser,

I would ask that to sales [at] jaguarpc.com as most of us probably only work with one of the control-panels, and do not have the luxery of knowing both types of control-panels by heart. However JPC does offer more then one config panel, so they should have experience with it and be able to give you a better adivise as i can.

Sorry i can't help you more as this.

Kindest regards,
Patrick

[jason]

jaguser,

Think about it this way: you have a finite amount of memory on your VPS, kind of like a pie. Each service (web, mail, ftp, cPanel, etc.) that users can connect to needs to be running on your server at all times. Each one of these services requires a set amount of memory, or a piece of the pie. Once all of the services take their share of the pie, there needs to be some left over. Each time a request is made on the server, a little bit more of the pie is used to handle that request, but after a few seconds it is put back for someone else to use.

The problem with cPanel is that it takes a larger piece of the pie than some of the other control panels do. That leaves less free memory available to process the individual requests. If you have a lot of concurrent requests (many users all trying to connect to the server at the same time) you could run out of this free memory, which would drastically slow down (or possibly even crash) the server. Therefore, if you choose to run cPanel, you need to be sure that you'll have a large enough pie to start out, so that there is enough to go around.

The actual number of users you set up on the server won't effect how much memory cPanel needs to run--it will require about the same amount of memory whether you have 2 uesrs or 200. However, the more users you add to the server, the more likely it beomes that more than one user will try to connect to that server at a given time. Each user that connects at one needs to share that leftover pie, you need to be sure that there is enough there for all of them. With cPanel on a discovery plan that would be difficult to do.

Sorry that I cannot give you any hard numbers, but I don't have access to different VPS setups to do benchmarking. As rainboy suggests, sales may be able to provide you with this kind of data.

--Jason

[jaguser]

Thanks,

I planned to post this question to sales. I just want to learn it from the users.

Butter, did you TOFTT today?

[Gwaihir]

JagPC doesn't even offer cPanel on the 128MB plan, because in their opinion it won't run (the plan as a whole, with cPanel on it). That to me means it's serious.

The problem with this WHM/cPanel is that it's designed for a normal "whole" server. Such a machine has 1-8GB of memory nowadays, so "so what" if cPanel permanently claims (say) 85MB out of that, right? Now you move it to a VPS where the whole pie is just 256MB and suddenly that 85MB is a third of all you've got. Now, think of how rarely you or a fellow administrator will be logged on and using that cPanel, compared to how often you have visitors running (other) pages. Suddenly it seems really silly to take as much as a third of your memory away from the primary task of serving your visitors and reserve it just for a tiny bit of extra convenience to the administrator(s)..

How will you notice? Well... memory REALLY equals speed in webhosting and that's speed for your visitors, not just for you as an admin. If there's little memory, the machine will have to go to disk for pretty much everything. If there's memory to spare programs will start cachine much used stuff in memory, which gives tremendous speed boosts. If there's truly too little memory, the OS will start swapping even the running programs themselves to disk (i.e. use a bit of disk space as memory). Once that happens performance will generally plummet down to a crawl and stay there for hours.

[rainboy]

JPC indeed doesnt offer cpanel, on such a vps host, and that is not more as logic as even Cpanel itself doesnt advise to run it on such a vps.

http://www.cpanel.net/docs/vps/ says:

Minimum CPU/RAM/HD:

P266

1000 CPU units and 128 Meg of ram will be required for a basic cPanel install.

1500 CPU units and 196 Meg of ram will be required if you wish to use spamassassin.

256 Meg of ram is recommended for either install choice.

4 Gig of hard drive space

So it would run with 128 (and doing nothing), but even the creator recommends 256Meg.

Kindest regards,
Patrick

[jaguser]

Thanks for the replies,

I know that jagpc doesnot offer cpanel for the 128mb plan. I was just trying to compare 128mb vs 256mb resources running interworx. Since as it said, memory is the main determining factor for speed (as far as webhosting is concerned), would it be correct to assume that a 256mb plan will run more than 2x faster than the 128mb plan?

Say, interworx takes 28mb of resources. That would leave 100mb of free memory on the 128mb plan, and 228mb free memory on the 256mb plan.

[Gwaihir]

Since as it said, memory is the main determining factor for speed (as far as webhosting is concerned), would it be correct to assume that a 256mb plan will run more than 2x faster than the 128mb plan?

That is quite possible, but very hard to state as a "hard fact".

There are some more factors: first, all memory is burstable here at JagPC. The 128MB and the 256MB are the guaranteed minimum you'll have at any given time on the given plan, but in general you'll likely have a bit more at your disposal at most times. How much more, I really wouldn't dare to guess. Then, how much you can make of the memory you have depends a lot on the sites you run and the specific tweaking you do. For example: if you serve mainly static pages, you'll want primarily a disk cache. If you have a lot of hits on a small set of PHP pages, you'll want an op-code cache (like APC), if you do very complex database stuff, you'll prolly want to give most of the memory to MySQL, etc.

As for 128MB plan vs 256MB plan: unless you have specific reasons to need a VPS, I would personally never pick the 128MB plan but look at a semi-dedicated (or reseller) account instead. So, I'd be comparing semi-dedicated vs. freedom plan, not discovery+panel vs. freedom plan.

[Ron]

The problem with burstable memory is that the other users get burstable memory too. That means that when "your" memory is being burst over to them, when you need the memory, either their data has to be swapped to disk, or you're gonna go to disk, before you get your memory back. There's just no two ways about that unless the machine has a huge amount of underutilized memory. People who need memory for things like MySQL installations leave their MySQL server up and consuming a huge chunk of their allotment of memory all the time. (You know that one way MySQL is able to be so fast is because it can use a huge cache, but not if you don't have the memory to assign to it. This is one reason that a shared account can be so much faster than a VPS with limited resources.)

Just doing a sort in MySQL (happens whenever you do joins, or use order by clauses) or use any kind of temp table, that normally is done in memory, unless you've set it up to go to physical disk, which would be a huge performance mistake. If you don't have enough memory, it has to go to swap. Same with any writing to /tmp. IIRC /tmp uses memory if possible, then goes to disk only if necessary. Lots of *nix processes use /tmp, so if you start to run out of memory, everything sl-o-o-w-s d-o-o-w-n.

I would guess that once a physical server is set up and sold out of VPS partitions, burstable memory becomes more of a liability than an asset for the machine. But that's just a guess.