CPU resources on a Linode: Constant or variable?
I just noticed that a site on my Linode that was loading in about a second now took about 4.5 seconds to load. What can impact the load time of a site on a linode (assuming that exactly the same code executes every time in preparation of the page)?
[EDIT:]I should mention here that I am aware that general internet traffic issues can impact load time - I am not, by any means, implying that linode's performace is the cause of a few slow load times. This is really just a general question about how things work at Linode and whether my VM is protected from neighbors who might affect the CPU cycles available on my linode. I've just been using linode for a few days and so far the performance overall is excellent!!
4 Replies
Short answer: This rarely happens, but your server can be affected by another user's resource usage.
Longer answer: Your server rests on a host that does have multiple servers on it, but each has a limit (based on plan size) of CPU they can use. Of course, this doesn't mean you're completely immune to ripples from another server, as multiple users pushing 100% of all of their cores on the same host can definitely cause issues. Linode keeps an eye on their hosts and looks out for problems such as this, taking actions as needed to ensure everyone is getting the service they should expect, but sometimes things slip under the radar.
As Jebblue stated, steal should be monitored, and running top to see what 'st' is at will tell the tale. If you notice issues, open a ticket and they will be able to help out with migrating.
If a site is loading slowly, you also may want to try these tools:
Good luck!
@sohsoh5:
Hey Patrick,
Short answer: This rarely happens, but your server can be affected by another user's resource usage.
….running top to see what 'st' is at will tell the tale…
Good luck!
Hmmm…. I'm starting to wonder about the effectiveness of the "steal" measure. I've noticed that the slowest site on my VPS usually comes in at 1.5 seconds load time but occasionally it comes in at very slow load times …like 5.5 seconds - and at those times, "steal" is still showing 0.0 seconds. Of course, I have absolutely no way of being sure that I'm measuring steal at the exact same instant that the request comes in from the test site (pingdom, keycdn, etc) but I've seen this behavior so often that I'm really starting to wonder about it.
However I can say with complete confidence that generally the load times are good (over 90% of the time) and these slow load times are a rarity (except on a few days when I've seen them happening about 60% of the time). I'm only questioning the reliability of the "steal" number as a way of identifying problem with slow load times.
Thanks for the help and advice.