No Free Lunch, but Brunch All Day

October 16, 2018

While the CAP theorem was a significant insight into the tradeoffs in distributed systems, it also led to a lot of confused expectations and cop-outs. At a high level, the CAP theorem states that a distributed system cannot simultaneously guarantee consistency, availability, and partition tolerance. As a result, many came to believe that they would have to choose either available, partition-tolerant tools (like NoSQL DBs) or consistent, partition-tolerant tools (like NewSQL DBs). Unfortunately, this turns out to be a bit of a false choice, since there is a significant amount of nuance to availability and consistency beyond black-and-white guarantees. In Bailis et al’s “Highly Available Transactions: Virtues and Limitations,” we get the chance to dig a bit deeper into specific features and signatures of consistency and availability that can be implemented, as well as a clear delineation of the ones that are (and are not) mutually exclusive.

CMSC 818e Day 13

October 15, 2018

These are notes taken during CMSC 818e: Distributed And Cloud-Based Storage Systems. Course webpage and syllabus here.

Replication and Consistency for Social Media

October 14, 2018

Replication and consistency needs are not uniform across all contexts; some applications we’ve read about are extremely write-intensive, such as GFS, which must enable users to modify files many times over while also supporting the freshest reads possible. Others, however, significantly constrain the actions users can take, effectively opening up unique opportunities for the implementation of highly specialized distributed systems. This is the case with Facebook’s f4, a distributed storage system designed to more efficiently house social media data as it ages.

CMSC 818e Day 12

October 10, 2018

These are notes taken during CMSC 818e: Distributed And Cloud-Based Storage Systems. Course webpage and syllabus here.

CMSC 818e Day 11

October 08, 2018

These are notes taken during CMSC 818e: Distributed And Cloud-Based Storage Systems. Course webpage and syllabus here.