This is the second in a two-part industry trends and perspective looking at learning from cloud incidents, view part I here.

There is good information, insight and lessons to be learned from cloud outages and other incidents.

Sorry cynics no that does not mean an end to clouds, as they are here to stay. However when and where to use them, along with what best practices, how to be ready and configure for use are part of the discussion. This means that clouds may not be for everybody or all applications, or at least today. For those who are into clouds for the long haul (either all in or partially) including current skeptics, there are many lessons to be learned and leveraged.

In order to gain confidence in clouds, some questions that I routinely am asked include are clouds more or less reliable than what you are doing? Depends on what you are doing, and how you will be using the cloud services. If you are applying HA and other BC or resiliency best practices, you may be able to configure and isolate from the more common situations. On the other hand, if you are simply using the cloud services as a low-cost alternative selecting the lowest price and service class (SLAs and SLOs), you might get what you paid for. Thus, clouds are a shared responsibility, the service provider has things they need to do, and the user or person designing how the service will be used have some decisions making responsibilities.

Keep in mind that high availability (HA), resiliency, business continuance (BC) along with disaster recovery (DR) are the sum of several pieces. This includes people, best practices, processes including change management, good design eliminating points of failure and isolating or containing faults, along with how the components or technology used (e.g. hardware, software, networks, services, tools). Good technology used in goods ways can be part of a highly resilient flexible and scalable data infrastructure. Good technology used in the wrong ways may not leverage the solutions to their full potential.

While it is easy to focus on the physical technologies (servers, storage, networks, software, facilities), many of the cloud services incidents or outages have involved people, process and best practices so those need to be considered.

These incidents or outages bring awareness, a level set, that this is still early in the cloud evolution lifecycle and to move beyond seeing clouds as just a way to cut cost, and seeing the importance and value HA, resiliency, BC and DR. This means learning from mistakes, taking action to correct or fix errors, find and cut points of failure are part of a technology maturing or the use of it. These all tie into having services with service level agreements (SLAs) with service level objectives (SLOs) for availability, reliability, durability, accessibility, performance and security among others to protect against mayhem or other things that can and do happen.

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The reason I mentioned earlier that AWS had another incident is that like their peers or competitors who have incidents in the past, AWS appears to be going through some growing, maturing, evolution related activities. During summer 2012 there was an AWS incident that affected Netflix (read more here: AWS and the Netflix Fix?). It should also be noted that there were earlier AWS outages where Netflix (read about Netflix architecture here) leveraged resiliency designs to try and prevent mayhem when others were impacted.

Is AWS a lightning rod for things to happen, a point of attraction for Mayhem and others?

Granted given their size, scope of services and how being used on a global basis AWS is blazing new territory and experiences, similar to what other information services delivery platforms did in the past. What I mean is that while taken for granted today, open systems Unix, Linux, Windows-based along with client-server, midrange or distributed systems, not to mention mainframe hardware, software, networks, processes, procedures, best practices all went through growing pains.

There are a couple of interesting threads going on over in various LinkedIn Groups based on some reporters stories including on speculation of what happened, followed with some good discussions of what actually happened and how to prevent recurrence of them in the future.

Over in the Cloud Computing, SaaS & Virtualization group forum, this thread is based on a Forbes article (Amazon AWS Takes Down Netflix on Christmas Eve) and involves conversations about SLAs, best practices, HA and related themes. Have a look at the story the thread is based on and some of the assertions being made, and ensuing discussions.

Also over at LinkedIn, in the Cloud Hosting & Service Providers group forum, this thread is based on a story titled Why Netflix' Christmas Eve Crash Was Its Own Fault with a good discussion on clouds, HA, BC, DR, resiliency and related themes.

Over at the Virtualization Practice, there is a piece titled Is Amazon Ruining Public Cloud Computing? with comments from me and Adrian Cockcroft (@Adrianco) a Netflix Architect (you can read his blog here). You can also view some presentations about the Netflix architecture here.

What this all means

Saying you get what you pay for would be too easy and perhaps not applicable.

There are good services free, or low-cost, just like good free content and other things, however vice versa, just because something costs more, does not make it better.

Otoh, there are services that charge a premium however may have no better if not worse reliability, same with content for fee or perceived value that is no better than what you get free.

Additional related material

• Cloud conversations: confidence, certainty and confidentiality
• Only you can prevent cloud data loss (shared responsibility)
• The blame game: Does cloud storage result in data loss?
• Amazon Web Services (AWS) and the Netflix Fix?
• Cloud conversations: AWS Government Cloud (GovCloud)
• Everything Is Not Equal in the Data center
• Cloud and Virtual Data Storage Networking (CRC) - Intel Recommended Reading List

Some closing thoughts:

• Clouds are real and can be used safely; however, they are a shared responsibility.
• Only you can prevent cloud data loss, which means do your homework, be ready.
• If something can go wrong, it probably will, particularly if humans are involved.
• Prepare for the unexpected and clarify assumptions vs. realities of service capabilities.
• Leverage fault isolation and containment to prevent rolling or spreading disasters.
• Look at cloud services beyond lowest cost or for cost avoidance.
• What is your organizations culture for learning from mistakes vs. fixing blame?
• Ask yourself if you, your applications and organization are ready for clouds.
• Ask your cloud providers if they are ready for you and your applications.
• Identify what your cloud concerns are to decide what can be done about them.
• Do a proof of concept to decide what types of clouds and services are best for you.

Do not be scared of clouds, however be ready, do your homework, learn from the mistakes, misfortune and errors of others. Establish and leverage known best practices while creating new ones. Look at the past for guidance to the future, however avoid clinging to, and bringing the baggage of the past to the future. Use new technologies, tools and techniques in new ways vs. using them in old ways.

Ok, nuff said.

Cheers gs

Greg Schulz - Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

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Cheers Gs

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