Multi-tenancy and bad landlords
Blog Article Published: 06/13/2010
So there's been a lot of discussion about multi-tenancy recently and what it means for cloud providers and users. To put it simply: multi-tenancy is highly desirable to providers because they can provide a service or a platform (such as WordPress) and cram a kajillion users into it without having to constantly customize it, modify it or otherwise do much work to sell it individually. The reality is that whether or not users like multi-tenancy, the providers love it, so it's here to stay. So what happens when you have a bad, or just unlucky landlord? In the last few months WordPress.com has had a number of outages:
What Happened: We are still gathering details, but it appears an unscheduled change to a core router by one of our datacenter providers messed up our network in a way we haven’t experienced before, and broke the site. It also broke all the mechanisms for failover between our locations in San Antonio and Chicago. All of your data was safe and secure, we just couldn’t serve it. http://en.blog.wordpress.com/2010/02/19/wp-com-downtime-summary/And more recently:
If you tried to access TechCrunch any time in the last hour or so, you probably noticed that it wasn’t working at all. Instead, you were greeted by the overly cheery notice “WordPress.com will be back in a minute!” Had we written that message ourselves, there would have been significantly more profanity. http://techcrunch.com/2010/06/10/wordpress-gives-us-the-vip-treatment-goes-down-on-us-again/So what can we do to support this leg (availability) of the A-I-C triad of information security? I don't honestly know. It's such a service/provider specific issue (do they control DNS? do you control DNS? can you redirect to another provider with the same service who has a recent copy of your data? If you do so can you then export any updates/orders/etc. back to your original provider when they come back? etc.) that pretty much any answer you'll get is useless unless it's specifically tailored to that provider or service. If you have an answer to this, please post it in the comments.