CQRS - Event Sourcing ( 10/11 )

Hi Devs !!! we are in the road again :)

This time hosting an event about "CQRS / Event Sourcing" next Thursday 10th of Novembre at the Netcentric offices.

CQRS stands for Command Query Responsibility Segregation. The idea behind is to split the conceptual model into separate models for update and display, which it refers to as Command and Query respectively following the vocabulary of CommandQuerySeparation. The rationale is that for many problems, particularly in more complicated domains, having the same conceptual model for commands and queries leads to a more complex model that does neither well.

Adrian is a seasoned software developer having worked 16+ years in designing and implementing enterprise solutions in large scale projects.

His expertise includes strong hands-on technical skills with Enterprise Applications based on JEE technology, in Enterprise Integration area, database development, object oriented analysis/design, data modeling and client/server application development. In the last years he has been working on a service design platform where he applied CQRS architectural principles.

In this talk he will give us a deep dive into the CQRS / Event Sourcing architectural principles with an example implementation in Scala and Akka Persistence backed up by Cassandra for event journaling and Titan for snapshot persistence.

Adrian Florea

Software architect
Java & Scala Developer
https://www.linkedin.com/in/acflorea

 

Don't forget to Register !!!!!

Cassandra & Java + Cassandra y Spark para el Internet of Things (29/1)

Hello JUGgers!

Este mes de enero no podía acabar sin otro evento por nuestra parte, ¿cierto? Pues como no podía ser menos hemos organizado un evento para finales de este mes, concretamente para el próximo jueves 29 a partir de las 19h. En esta ocasión y en colaboración con el Meetup de Cassandra de Barcelona os invitamos a una sesión completísima sobre Java, Cassandra, Spark y su relación con el mundo IoT.

En esta ocasión tendremos 2 charlas: una primera introductoria (20'-30') para conocer Cassandra y su relación con Java y a posteriori otra más concreta (45'-55') centrada en la experiencia del uso de esta base de datos noSQL y Spark en un complejo entorno corporativo.

En la primera parte, Jose Hernández nos dará una rápida introducción a Cassandra y su lenguaje de consulta CQL3, para que puedan seguirnos los no iniciados. A continuación veremos como conectarnos desde Java al cluster y a partir de aquí empezaremos a lanzar 'statements'. Sin olvidarnos de temas más avanzados, como la ejecución de múltiples queries asincronas y en paralelo que nos permitirán mejorar los tiempos de respuesta de nuestra aplicación. Jose es Ingeniero electrónico especializado en sistemas de monitorización distribuida, lo que ahora es el Internet de las Cosas (IoT). La explosión de datos debida la computación embebida y a las conexiones móviles le llevo a adentrarse en Cassandra y el big data y en la actualidad es Director Técnico de Isthari, partner de DataStax.

A continuación Josep Casals, nos expondrá la experiencia de British Gas Connected Homes con Spark y Cassandra. Entre otras nos explicará sus conocimientos y aprendizaje en aplicaciones tales como desagregar el consumo de electrodomésticos a partir de medidas de contadores inteligentes o predecir fallos en instalaciones partir de medidas de sensores. La presentación incluirá ejemplos de código para algunas técnicas básicas y se discutirán las lecciones aprendidas durante la puesta en producción de algoritmos de Data Science sobre grandes conjuntos de datos. 

Actualmente Josep es Lead Data Engineer en British Gas Connected Homes y sus especialidades comprenden la innovación tecnológica, los sistemas de datos y el Internet of Things.

Estamos todavía concretando el sitio -que esperamos anunciar en breve-, pero aún así no te olvides de reservar tu plaza a través de MeetUp que hay pocas plazas y aprovechamos también para saludar al Meetup de Cassandra de Barcelona por el esfuerzo de organizar este evento conjuntamente.

¡Os esperamos este jueves 29!

Introduction to Apache Cassandra - Summary

Hi devs!

As we announced on the last entry, on April 1st, we attended a terrific Cassandra talk with Colin Clark as the speaker, on which he explained the use of Cassandra they made at Datastax for a distributed concurrent and high availability Stock Exchange monitoring and management application (a very simplified view of what the application actually did, of course).

At first, we were given an overview of the project, what it entailed, what were the client's needs and the protocols used for information exchange. With that information, we were shown how the system was built around those foundations. Colin described the different layers of their system, the ever functioning monitoring and processing layer that aggregated all real time data coming from the stock exchange sources so as to empower business analysts to take sound strategic decisions.

This information processing system couldn't have been made without Cassandra, the key technology, since this NOSQL database is designed from the ground up to be scalable, thanks to it's distributed node architecture. As was debated later on the questions round, the alternatives weren't up to the needs of the application, in performance, availability and cost (both in time to implement and on licenses to pay).

Colin Clark also gave us some pointers on best (and worst) practices to migrate a relational database backed application to a nosql like Cassandra.

All in all, a very good talk, and one that will open further collaborations with Datastax. Stay tuned for more info on that the next months, big things are yet to come this year!

Talk's video:

Introduction to Apache Cassandra

Talk in English !!!

Hi devs !!!!

We are back to the stage this April 1st  with a new cool presentation. This time is about Apache Cassandra, the famous No-SQL database developed by Facebook and evolved as an Apache Foundation project.

Colin Clark will outline how Cassandra was used in a large system that performed post-trade compliance and surveillance for a major US stock exchange. He'll outline the components used, how they were tied together, and the end motivating factors behind choosing Cassandra for the data store.

Colin has been using Cassandra now for 5 years in high speed, mission critical applications and has over 25 years of experience in global capital markets.  During that time, Colin has worked for a number of exchanges, broker/dealers, investment managers, regulatory bodies, on-line trading firms including NYSE Euronext, Boston Stock Exchange, London Stock Exchange, Paris Stock Exchange, Goldman Sachs, Fidelity, E*Trade, Scottrade, Citi, and numerous others.

Event Details

When   : April 1st 2014, 18.30 h

Where :  Punt Multimedia ( Casa del Mig )
              Carrer Muntadas Nº 1-5 (Parc de l’Espanya Industrial)
              08014 Barcelona

           

We expect you to come !!! We have limited places so do not forget to register in our Meetup Event.

Register to the Event