Disambiguating ACID and CAP
The ACID properties and the CAP theorem are two important concepts in data management and distributed systems. It’s unfortunate that in both acronyms the “C” stands for “Consistency,” but actually means completely different things. What follows is a primer on the two concepts and an explanation of the differences between the two “C”s. What is […]
How we Test at Volt Active Data
When you evaluate a database to use in your application stack, you usually look at the features, the performance, the price, and the fit. You take for granted that the data is correct, that the features work as documented, and that the resiliency of your distributed database meets the promises made by the marketing team. […]
Accelerating continuous integration with Docker – an intern’s story
Continuous integration (CI) has become a fundamental process in many software-based companies in recent years. Fortunately, frameworks such as Jenkins do most of the heavy lifting and make it flexible for the engineering team to examine and improve the process. With the increasing popularity of lightweight virtualization, CI has begun to embrace technologies like Docker. […]
An intern’s experience with Volt Active Data Materialized Views
My name is Yiqun Zhang and I worked as a software engineering intern on the SQL core team at Volt Active Data during the summer. The experience of working with so many smart and talented people was so much fun. I was proud to be part of the team. My work focused mainly on the […]
Bringing Rack-Aware Topology to Volt Active Data
One of the key tasks during initialization of a Volt Active Data cluster is determining cluster topology. The topology includes placement of the partition masters and replicas on physical Volt Active Data nodes. Once determined, the topology does not change unless node failure or elastic scaling happen. For some years, Volt Active Data used a [...]
Getting around the Transparent Huge Pages trap in Linux
A couple of weeks ago, an interesting issue came up in the field. The symptom was that the resident set size (RSS) of the Volt Active Data process would keep growing when the database was idle. The symptom only manifested itself on Red Hat Enterprise Linux (RHEL) 6.6 in KVM. There was no client workload, […]
