Memory is allocated to each Linode. CPU is burstable. Any Linode can use all the CPU that's available.

It would definitely be "frowned upon" to use all your CPU all the time.

That's what I suspected. Thank you for confirming, I'll definitely avoid it. I can see this being a frequent curiosity for new users - perhaps an FAQ mention would be in order? Just a thought.

@Xan:

It would definitely be "frowned upon" to use all your CPU all the time.

On the contrary! It is my understanding this is NOT the case.

Please use all the CPU you wish, is my understanding. No Frowning. I suggest you ask the Linode staff yourself in an email or support ticket rather than relying on our "opinions".

James

@zunzun:

I suggest you ask the Linode staff yourself in an email or support ticket rather than relying on our "opinions".

Please do, now I'm curious. Because if everybody were doing that, there'd be no burst at all.

I found this, at one point when wondering about this:

http://www.linode.com/forums/viewtopic.php?p=7426#7426

@CDMoyer:

I found this…

There is this from the Linode FAQ, looks like a 'No Frowning' policy to me:

http://www.linode.com/faq.cfm#how-do-i- … are-of-cpu">http://www.linode.com/faq.cfm#how-do-i-get-my-fair-share-of-cpu

James

The FAQ refers to the "worst case scenario", which is what you guys are trying to achieve by hogging all the CPU. In the IRC chat that CDMoyer dug up, Caker refers to lowering the priority of chronic CPU abusers. That sounds like frowning to me.

And apart from that, it's just plain rude and bad form to chew up the whole CPU. This is a shared environment. I thought it was a bad idea when Linode made Gentoo available, for this reason, but I guess it's working out okay. FaH certainly wouldn't.

EDIT: I don't mean DaninFuchs is trying to be a CPU hog. He was asking the simple question whether CPU was statically allocated or not, and based on that he was going to run BOINC or not. I think that question has been answered and this thread has digressed. I do hope you join Linode, DaninFuchs!

@Xan:

Caker refers to lowering the priority of chronic CPU abusers.

I will open a support ticket and ask if this is the case.

James

Ticket opened as follows;

There is currently a forum thread in which it seems to be Linode policy to lower the kernel scheduling priority for those Linode users that are labeled "chronic CPU abusers".

@Xan:

Caker refers to lowering the priority of chronic CPU abusers.

1) Is priority reduction for CPU usage the current policy?

2) What determines application of the label "chronic CPU abuser"?

3) Is it currently being applied to any Linode customer?

4) Is it being applied to my site, zunzun.com?

James

Answers below.

1) Is priority reduction for CPU usage the current policy?

Yes

2) What determines application of the label "chronic CPU abuser"?

Significantly higher than average CPU usage consistently for prolonged time such that it causes decreased performance for the other Linodes sharing the host.

3) Is it currently being applied to any Linode customer?

Not that I am aware of.

4) Is it being applied to my site, zunzun.com?

No.

Thanks for finding that out, zunzun; it's nice to have some more authoritative information.

I'd summarize it as "use all the CPU you want, but don't go nuts with BOINC or Folding or by letting processes run away." Seems more than fair to me.

Hate to take an already OT thread and make it worse, but…
@Xan:

I thought it was a bad idea when Linode made Gentoo available, for this reason, but I guess it's working out okay.
My linode is a lightly loaded static web and mailserver, running Gentoo, updated weekly:

Your Linode has averaged

0%

of one Host CPU for this month

DURING this weeks update:

cat /proc/io_status

iocount=322162 iorate=33 iotokens=2000000 tokenrefill=512 token_max=2000000

I'd choose a host populated with Gentoo installs over one full of number crunching apps any day :)

@Xan:

Thanks for finding that out, zunzun; it's nice to have some more authoritative information.

My wife's Burmese nickname is zunzun, hence zunzun.com. My name is James - and you're welcome!

James

P.S. Of course 'chronic CPU abuser' could be someone running Vista, heh heh heh…

How about someone running 3 vista machines? :D

Does the answer of this question change if/when everyone is using Xen?

It wouldn't, no. The CPUs are still shared in the same way. Every Linode will be able to see all the CPUs in the system instead of just one, which would seem to me to exacerbate the problem, since a single Linode could run away with the whole machine. But in any case, Xen doesn't change that we're all sharing the same CPU power.

Snipped from #linode this evening:
> 23:13 < tonyyarusso> So there's no real protection against a linode neighbor doing something stupid that overloads it, thus taking your site down?

23:15 < tonyyarusso> I haven't actually heard of it being an issue, but am a bit curious if it's possible.

23:18 <@caker> tonyyarusso: on UML, we utilize the standard Linux CPU scheduler which does a fine job fairly allocating CPU time

23:18 <@caker> tonyyarusso: on Xen, we use Xen's credit scheduler, which does the same thing

23:19 < tonyyarusso> caker: wish I knew something about schedulers… Oh well, I'll take your word for it.

23:19 <@caker> let's put it this way: cpu time is guaranteed

I've noticed when using VMWare, I can have a guest system's cpu pegged, and yet the host's cpu is not. I was just wondering if this would have been the case with Xen, but I guess it's not?