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Showing posts from January, 2021

A chair named Cherry

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Cherry is a body-bilt chair. I met her in a conference room in Microsoft Redmond Building 43, during my sabbatical at Cosmos DB . It was love at first sit. You see my office chair was crappy and uncomfortable. But sitting on Cherry was like sitting on clouds. It had great padding and perfect support. It is as if it has been molded for my body. On an impulse, I liberated Cherry and moved her to my office in Building 44. I had a blissful time working with Cherry on my desk. A couple days later, during my stroll through the buildings, I realized I was the target of a manhunt. They had posters of Cherry on every window.  It was too dangerous for me to be out there. Look I didn't know. I didn't think removing the chair would create this much trouble. Who was this person anyway? What kind of person would give a chair a name? Well, I knew I didn’t want to mess with that kind of a person. I still miss Cherry. My current chair is an Aeron Miller, but nowhere as comforting and supportive...

Virtual Consensus in Delos

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This paper has been awarded a best paper award at OSDI20 , and is authored by Mahesh Balakrishnan, Jason Flinn, Chen Shen, Mihir Dharamshi, Ahmed Jafri, Xiao Shi, Santosh Ghosh, Hazem Hassan, Aaryaman Sagar, Rhed Shi, Jingming Liu, Filip Gruszczynski, Xianan Zhang, Huy Hoang, Ahmed Yossef, Francois Richard, and Yee Jiun Song at Facebook, Inc. Delos is the database that stores control plane state for Facebook, building over a shared log system. Each Delos server stores a local copy of a full database, which keeps materialized state of the log, as a Delos table. This DB/ is maintained over the shared log as RSM by just reading commands from the log in sequence and applying them for materializing on the table. Virtual consensus This high level setup is familiar, so let's dive deeper to get to the novelty in this work. Delos uses virtual consensus, which is a fancy way of saying the following. The DB is maintained over a virtual log, which consists of loglets, each of which is implemen...

Trial and error

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Like many of you I watched The Queen's Gambit and loved it. The settings of scenery and decors in 1960s were mesmerizing.   And like many of you, this rekindled the interest for chess in me. Growing up, I didn't play chess much, but my younger brother got into it as a middle school student. He bought books detailing chess games and studied them. He got a city-wide championship and such. I didn't get much into it, because I guess I didn't think of it as a serious enterprise and didn't want to expend too much energy into it.  I had this Android chess app on my phone, and I started playing with that instead of my downtime Sudoku playing . In this chess app, it is very easy to undo moves, and try other moves. I play against the machine, and yes undoing is cheating, but I use it a lot to explore different scenarios at critical points in the game. I have been very surprised about how much this accelerated my chess learning. I was able to make progress through several har...

Facebook: The Inside Story (2020) by Steven Levy

I didn't know much about Facebook's story, so many things in the book was news to me.  Here are my two main take-aways from the book.  There are many inaccuracies in "The Social Network" movie . The founding story is quite different. There had been many challengers claiming they had the "facebook" idea. But social networking was not a new idea. There was even a digital facebook in Exeter at Zuckerberg's boarding high school. Of course there is a luck factor involved, but Zuckerberg should get credit (and blame) for successfully executing this vision at large scale. In this case, the quote is apt: Ideas are worthless, execution is everything. "Never attribute to malice that which is adequately explained by stupidity/incompetence." Facebook has been very reckless and greedy. They botched up things badly, many times, over and over. But they are not inherently evil. The greedy obsession with growth did Facebook in. Zuckerberg has to have everything...

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