Pre-sales Q about CPU loading and availability

Unless your Rails app is incredibly ill-designed, a few hundred pageviews a day would be a piece of cake even for the cheapest linode. Multiply your pageviews by 100, and a Linode 360 still won't even blink – provided, of course, that your app is at least moderately well-designed. (Or did you mean "a couple of hundreds of thousands" ?)

Other hosts often talk about CPU minutes, or guaranteed MHz. I don't think those numbers mean anything, but if you really want numbers, you can easily make up some. For example, if you use a Linode 360, there are 40 linodes sharing a Quad-core Xeon CPU which runs at 2.0GHz I believe. That's approximately 200MHz for your Linode, or 1440 / 40 = 36 minutes per day. Of course, most of the other Linodes are mostly idle most of the time, and you get to use whatever CPU is available.

On a more subjective note, I've found that even the cheapest Linode is very very fast. Sometimes my linode feels even faster than my home computer (low end Core 2 Duo)…. In most cases, with a VPS like this, it's disk I/O rather than the CPU that becomes the bottleneck.

@hybinet:

…On a more subjective note, I've found that even the cheapest Linode is very very fast…

Thanks for the reply. I'm sure that the minimal plan will be fast enough for me.

The real issue for me is whether someone else's runaway process has the ability to starve the CPU as far as my processes are concerned. This is the situation I currently have.

@umdenken:

me is whether someone else's runaway process has the ability to starve the CPU as far as my processes are concerned. This is the situation I currently have.

I'm going to answer my own question in case anyone else is interested in this.

My current host offers OpenVZ-based virtualization, and so that was another option I was considering. So I read up on "OpenVZ vs Xen", and found out, that essentially, Xen's only downside is it's relatively difficult learning curve to set up. This, of course, is what Linode has already taken care of. And further – Xen's biggest advantage is its insulation from the other VMs, at the relative cost of not being able to pack in as many VMs as is possible with VZ.

I haven't really found anything specifically addressing the CPU issue, but this sounds good enough that I'm going to sign up.

@umdenken:

I haven't really found anything specifically addressing the CPU issue, but this sounds good enough that I'm going to sign up.

With linode, I hope?

@freedomischaos:

@umdenken:

I haven't really found anything specifically addressing the CPU issue, but this sounds good enough that I'm going to sign up.

With linode, I hope?

Yes. :-) And I'm up and running…

I can tell you that I run a reasonably large (3,000 posts, 2,500 users, ~20k hits per day) Drupal-powered site on an Linode 720 and the machine doesn't even blink.

I use an average of less than 1% of the CPU. Check out my system graphs for yourself. (That big spike on Saturday night was when I upgraded Drupal)

– Doug

@hybinet:

… there are 40 linodes sharing a Quad-core Xeon CPU which runs at 2.0GHz I believe. …

The hosts have dual quad-core Xeons. 8 cores total. Though each Xen Linode only gets access to 4 of the cores.

I'm not sure about the clock speed. Someone with a Xen node could check /proc/cpuinfo.

(UML doesn't support SMP, so you only get one core there…)

dallas69

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Xeon(R) CPU           L5335  @ 2.00GHz
stepping        : 11
cpu MHz         : 2000.070
cache size      : 4096 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae cx8 apic cmov pat clflush acpi mmx fxsr sse sse2 ss ht nx constant_tsc pni
bogomips        : 4004.47

• 4

freemont44

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 23
model name      : Intel(R) Xeon(R) CPU           L5420  @ 2.50GHz
stepping        : 6
cpu MHz         : 2500.086
cache size      : 32 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae cx8 apic cmov pat clflush acpi mmx fxsr sse sse2 ss ht nx constant_tsc pni
bogomips        : 5004.75

Processors 0->3 show up. This is on a basic linode360

newark12

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 23
model name      : Intel(R) Xeon(R) CPU           L5420  @ 2.50GHz
stepping        : 6
cpu MHz         : 2500.090
cache size      : 6144 KB
physical id     : 1
siblings        : 4
core id         : 2
cpu cores       : 4
apicid          : 6
initial apicid  : 6
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae cx8 cmov pat clflush mmx fxsr sse sse2 ss ht nx constant_tsc pni ssse3 sse4_1
bogomips        : 5045.75
clflush size    : 64
power management:

@egatenby:

newark12

Interesting! Yes – so I've switched most of my sites over to my new 360, and the increase in reliability and speed has been awesome.

I just yesterday get a linode360, but doing a more /proc/cpuinfo gets me only 2 Xeon@2.50ghz isn't supposed to be quad core? btw I'am on dallas facility.

If you're only seeing two cores, file a ticket and I'm sure it'll be fixed quickly.