Notes on Distributed Systems for Young Bloods (2013)

It's a step backwards that distribution is being dealt with at the application level. Tandem Computers [1] had distribution at the OS and database level working well in the 1980s. The technology is still available from HP. Tandem's NonStop OS is fundamentally different from UNIX-like OSs. UNIX is a time-sharing system with a file system. NonStop is a transaction system with a database system. There's very little state outside the database. Programs are started, do one transaction, and exit. If…

The article should really mention CALM (Consistency as Logical Monotonicity)[1], it's much easier to understand and a more fundamental result than CAP. It is also much more applicable and enables people with little experience to build extremely robust distributed systems. Idempotence, CRDTs, WALs, Raft, they are all special cases of the CALM principle. [1]: https://arxiv.org/pdf/1901.01930

Great article. There are just a few things that I would add to it. 1. The metrics comment could not be more true. You cannot think hard enough about the actual problems you will encounter and what metrics you will have. Have a common way to pull information about each service, and to analyze it in some common place. 2. Standardize, standardize, standardize. When someone is answering a page at 2 AM and has to deal with a component of…

As I read the first five items on that list, each one made me think more and more "then isn't the answer to not write distributed systems?". But then the last item gives almost the opposite advice: "Extract services". If you don't need (micro)services, don't build them -- they only introduce complexity in communication between components, build tooling, diagnosing issues, and they slow things down. It's amazing what you can do on a single machine, or, beyond that scale, a…