Linode dashboard, Your Linode has averaged ...
Can you tell me please how do I read exactly the
"Your Linode has averaged XX% of one host CPU"
please?
What does it means?
This value refers to the one I can see using the uptime command or
or it refers to a different value? different meaning?
Usually my average value goes from one to two.
my VPS generate PDF when customers ask for it and it's quite cpu intensive, this higher the average.
What happen if I reach a high value? My linode will be limited automatically? What is the value that I cannot surpass?
Hope that someone can answer to all my questions.
Thanks.
6 Replies
Linode hosts are generally 8-core dual-Xeon hosts, and individual Linodes can burst up to 4-core's worth if otherwise unused - when busy, they're shared equally among other Linodes on that host. That's the hard limit for your Linode - the actual CPU available varies instantaneously based on other Linodes sharing the same set of cores on your host. Larger Linode configurations share that set of cores with fewer peers.
The Linode Manager value is telling you what percentage of a single core you are using on average. That should correlate to what you see locally in terms of percentage of a single core (understanding that your local Linux CPU usage might go as high as 400%), though I'm not sure the Linode Manager will show values above 100%. That's not what uptime shows (which is a load average based on runnable processes), but for example, the sort of CPU usage you'll see in top or via monitoring with munin.
Of course, the Linode Manager is a monthly average so it takes quite a bit of CPU usage to get that to be high overall on average.
Generally you can only get CPU if nobody else wants it (or else its shared equally) so I wouldn't worry too much. Certainly averaging 1-2% is nothing.
As a quick estimate, let's say it's a Linode 512, with around 40 Linode's on a single host. So that's about 20 per quad-CPU, or 5 per CPU. So dividing host CPU equally among all Linodes is in the 20% of one CPU ballpark - a little less accounting for host overhead.
So unless you're above 20% or so, you aren't necessarily even using a pro-rated share of the CPU available. Though if you're showing that as an average, you're probably bursting much higher at times, but you're also likely lower at other times, so it all works out. And that's with a Linode 512 - the higher plans have fewer guests on each host, so the percentage threshold of a pro-rated share goes up.
-- David
I think…
-Chris
Last question…
On my dashboard after some benchmark I can see:
MAX: 175%…
That value can go up to 400%???
400% means four core in full load???
Am I right?
Thanks.
@caker:
@sblantipodi:400% means four core in full load???
Correct.-Chris
many many thanks.
Bye.