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Links for 2014-11-20

  • Update on Azure Storage Service Interruption

    As part of a performance update to Azure Storage, an issue was discovered that resulted in reduced capacity across services utilizing Azure Storage, including Virtual Machines, Visual Studio Online, Websites, Search and other Microsoft services. Prior to applying the performance update, it had been tested over several weeks in a subset of our customer-facing storage service for Azure Tables. We typically call this “flighting,” as we work to identify issues before we broadly deploy any updates. The flighting test demonstrated a notable performance improvement and we proceeded to deploy the update across the storage service. During the rollout we discovered an issue that resulted in storage blob front ends going into an infinite loop, which had gone undetected during flighting. The net result was an inability for the front ends to take on further traffic, which in turn caused other services built on top to experience issues.
    I’m really surprised MS deployment procedures allow a change to be rolled out globally across multiple regions on a single day. I suspect they soon won’t.

    (tags: change-management cm microsoft outages postmortems azure deployment multi-region flighting azure-storage)

  • AWS re:Invent 2014 | (SPOT302) Under the Covers of AWS: Its Core Distributed Systems – YouTube

    This is a really solid talk — not surprising, alv@ is one of the speakers!

    “AWS and Amazon.com operate some of the world’s largest distributed systems infrastructure and applications. In our past 18 years of operating this infrastructure, we have come to realize that building such large distributed systems to meet the durability, reliability, scalability, and performance needs of AWS requires us to build our services using a few common distributed systems primitives. Examples of these primitives include a reliable method to build consensus in a distributed system, reliable and scalable key-value store, infrastructure for a transactional logging system, scalable database query layers using both NoSQL and SQL APIs, and a system for scalable and elastic compute infrastructure. In this session, we discuss some of the solutions that we employ in building these primitives and our lessons in operating these systems. We also cover the history of some of these primitives — DHTs, transactional logging, materialized views and various other deep distributed systems concepts; how their design evolved over time; and how we continue to scale them to AWS. “
    Slides: http://www.slideshare.net/AmazonWebServices/spot302-under-the-covers-of-aws-core-distributed-systems-primitives-that-power-our-platform-aws-reinvent-2014

    (tags: scale scaling aws amazon dht logging data-structures distcomp via:marc-brooker dynamodb s3)

  • How Curiosity, Luck, and the Flip of a Switch Saved the Moon Program | Motherboard

    “SCE to off?” someone said. The switch was so obscure that neither of his bosses knew what he was talking about. “What the hell’s that,” blurted out Gerald Carr, who was in charge of communicating with the capsule. The rookie flight director, Gerry Griffin, didn’t know either. Sixty seconds had passed since the initial lightning strike. No one else knew what to do. The call to abort was fast approaching.  Finally, Carr reluctantly gave the order in a voice far cooler than the moment. “Apollo 12, Houston, try SCE to Auxiliary, over.”

    (tags: spaceflight stories apollo sce-to-aux power lightning weather outages simulation training nasa)