Android suspend

In order to save battery android suspends whenever the screen is locked or after a certain timeout. Suspend shuts down the CPU and “non-essential” radios such as WiFi and GPS but not the AlarmManager, GSM and CDMA[2]. When applications need to perform important updates they can require that the CPU stays ON, this is achieved… Read More »

Random Walks on LastFM

Big social networks don’t often disclose their data to other interested individuals. Their data and users add value to their business. So in order to estimate certain parameters such as the average age or other user characteristics or interests, we need to access the nodes individually. The way this nodes are accessed depends on the… Read More »

How can we tell science from nonscience?

So I have been reading this very interesting book called “Philosophy of Science: The Central Issues”. It has proven to be a nice reading so far and tries to share opinions on the questions we often ask our self. Like “what differs science from religion?” or “is there a demarcation between science and no science?” The… Read More »

Impact of reliability in the scalability of Flume

I will be describing the mechanisms to provide fault tolerance in Flume as well as its impact on scalability due to the increasing number of flows and possible bottlenecks. In this case, reliability is the ability to continue delivering events and logging them in the HDFS in the face of failures, without losing data. This… Read More »

Dimemas architecture and Multi-level cache simulations

So the conclusion of the Measurement and Tools course of UPC consisted on delivering a report on the performance analysis of a NAS benchmark on a simulated super computer and to test some parallel applications on different simulated cache architectures. The used tools consisted of intel’s pin tool and Dimemas. From the first, we took… Read More »

Speed Through installation of Flume-NG on Amazon AWS

This is a thunder-speed (:P) through installation of Flume NG (1.x) on Amazon AWS. I tried to make it as fast as possible. Note that for a final product, more attention should be spent on security issues. Tools used: puttygen putty scp pssh cloudera manager 3.7 flume-ng Operating System: Ubuntu (on my machine) Suse on… Read More »

Update on Offline Routing and Regenerator Placement and Dimensioning

I should have posted some results already on this topic since the deadline to deliver the presentation has already passed. It seems that we have made a mistake while implementing the decoder function in the BRKGA java code. The Routing and Placement seem to be well addressed but we are getting wrong values in the dimensioning. Still… Read More »

Flume-based Independent News-Aggregator

As a final project of our scalable distributed systems course, me and two friends decided to implement a system that would read RSS entries from multiple websites and provide access to it through a search engine, web API or a nice webpage. We found that flume would do the trick since it allows us to… Read More »

Easter Eggs!

Procrastination (not really) and imagination made me come up with the idea of hiding a few easter eggs in this blog! Sounds like a great idea, I always liked puzzles! So far there is still only the infamous golden pet hidden somewhere but I’m am thinking of making an actual game out of this blog… Read More »

Biased Random-Key Genetic Algorithm

I have been writing the report on the BRKGA meta-heuristic so I will quote a short description I wrote about this genetic algorithm 🙂 We have chosen the Biased Random-Key Genetic Algorithm (BRKGA) meta-heuristic in order to effectively solve this complex optimization problem. Typically, genetic algorithms evolve a population applying the principle of the survival… Read More »