Reference to blogs, tweets, discussions, etc that caught my attention during the last week.

Data Architecture

Immutability changes everything” by Pat Helland deals with immutability as a key architectural concept. Append-only computing instead of changing data is also a key concpt in Nathan Marz’ Lambda Architecture. Pat Helland distinguishes storing data on he inside (stroring in a RDBMS: data is changeable, schema is prescriptive, no versioning) vs storing data in the outside (storing data not in a RDBMS: data is immutable, schema is descriptive, versioning of data).

Data Flow

Mammad Zadeh describes in his blog article “Kafka at LinkedIn: Current and Future” use cases (monitoring application health, messaging, etc), current ecosystem (Avro event, audit service, etc) and the future (authentication and authorization, quotas, cost efficiency, Espresso intgration, etc.) for Kafka at LinkedIn. Some statistics: 550 Billion events a day, peak throughput with 8 million incoming messages a second and 32 million outgoing.

In the last blog from 04/2015 I referenced slides by Martin Kleppmann from /dev/winter 2015. He know wrote a transcript of a his talk “Stream processing, event sourcing, reactive, CEP… And making sense of it all“.

Data Analytics

Timeline of statistics” visualization from past (500) to present (2012 by ASA and Royal Statistical Society.