Month: September 2015

Paper Notes on “CORFU: A distributed shared log” [TOCS’13]

Last Monday we looked at Tango, a system for replicating a data structure to provide linearizable semantics and fault-tolerance. Tango is built up on CORFU, a replicated log, built over storage nodes. This paper notes article covers “CORFU: A distributed shared log” also by Balakrishnan et al. from TOCS December 2013. I believe that this Read More

Paper Notes on “Tango: Distributed Data Structures over a Shared Log” [SOSP’13]

The following is a paper notes article on “Tango: Distributed Data Structures over a Shared Log” by Balakrishnan et al. from SOSP 2013. The article focus on the main body of the paper and I will cover Tango’s streaming and transaction support in a separate article, sometime in the future. I have covered this paper Read More

BBC Radio 4: Any questions?

I asked a question on today’s BBC radio 4 show “Any questions?”, http://www.bbc.co.uk/programmes/b06b3ny4, skip to 42:07 to hear me nervously ask “How can we protect the rights of citizens in an increasingly digital world?” and hear the panel’s response. The responses where fairly disappointing but it helps to keep the debate alive. Read More

Azure Latency Pilot Study: Part 4 – Variation in results with time

So far in this study, we have only considered the aggregated measurements and how they vary depending on the VMs used. In this post, we will considered how the RTT measurements may have changed over time. The following 5 plots show the RTT as observed by each machine over time. The y axis stops as Read More

Azure Latency Pilot Study: Part 3 – Machine specific results

In this post we will be looking at the results for the Azure latency Pilot study described last week. Yesterday, we started by looking at the aggregated results and found that the measured RTT was larger then expected. Today, we will look at how the results vary depending on which VMs the measurements where taken Read More

Azure Latency Pilot Study: Part 2 – Aggregated results

This is post we will be looking at the results for the Azure latency Pilot study described last week. We will starting by looking at the aggregate results, disregarding the time a measurement was taken and which machines the measurement was taken between. The 22332 data points have been processed in Python3, in particular using Read More

Azure Latency Pilot Study: Part 1 – Experimental Setup

This post, the first in a short series, discusses a simple overnight pilot study of measuring network characteristics on Microsoft Azure. This study was to be the first of many. Its purpose was to test the tools and gave some initial measurements, thus informing the the design of more substantial measurement studies in the future. Read More