Going Viral

To see a site go viral from a technical point of view is not something you get to see that often. This week was the exception to that rule. Generally speaking the experience was a little concerning, but generally good as it was very much a learning opportunity.

Relatively speaking the site in question was busy enough - delivering around 30Mbit of outbound traffic day in, day out.

Then you start noticing the anomalous alarms - and this VM is now pulling close to 150Mbit at peak times - topping out at 180MBit.


So - here is a little insight...

BELOW: The port spikes like you would not believe. Delivering as much as ten racks of shared and dedicated hosting.

BELOW: CPU bouncing off of the throttle limits occasionally.

BELOW: Interface before and during spike.

Now here is a thing. This is not even a dedicated server. This is a Xen based Virtual Machine running within OnApp.

So sure - its all shiny SSD distributed storage, and 10GigE interconnects... but this is virtual cores, virtual threads, and sharing a machine, memory, CPU, interrupts, storage, network with a tonne of other machines.


So what causes this? Well Lad Bible to start with - then about nine million shares on Facebook and the like.

The site saw something in the region of 6 Terabytes transferred in terms of page and content views in the space of 4 days.

It's amazing to see what a piece of hardware can deliver.... before it is even optimized.

Bouncing off the CPU limiter, and the port limiter from time to time. Enabling autoscale to allow a little more breathing room - with more cores, then configuration tweaks, and then back to the developer for code optimizations. You really do get the feeling that given more resources it would have been able to deliver even more. Not bad for a single host delivering thirty other entire Operating Systems at the time.

Not quite a Slashdotting - but a fair old punch in the resources... not to mention wallet.

Optimizations and time passing the requirements start to fade as we line up a CDN to do the heavy lifting... it is none the less a thing to behold. Especially given the platform took it in it's stride... and the limitation being the soft quotas put in place via the controlling platform OnApp on the Xen instance. "This. Was. A. VM." -  Okay... maybe this is just me finding that pretty much amazing having seen dot com era machines cripple and die under a fraction of that traffic.

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