Search Computing Blog

Continuum - a project developed and maintained under the Apache umbrella – is a continuous integration server that is fully integrated with many popular build systems (most notably maven2) and supports automated building, testing and releasing of applications. Continuum can be either deployed as a stand-alone server or inside an application container; this tutorial is focused on the latter scenario since it involve some non-trivial preparation.

The objective is to deploy Continuum inside Tomcat 6 and set it up to build and test our project at every change.

The deployment environment is the following:

Debian squeeze
tomcat6        6.0.28
openjdk-6-jdk  6b18-1.8.7
maven2         2.2.1-5
subversion     1.6.12dfsg-5

The package mentioned above can be installed and set up automatically using aptitude. Continuum – however – is not packaged and needs to be installed manually. In this tutorial we use Continuum 1.4 beta (the war, but the tar.gz will come in handy during the deploy).

Before setting up the web application, we need to setup the workspace for Continuum; Tomcat, in Debian, runs as a separate user (tomcat6) and is not able to write outside its directories. To host Continuum configuration files, databases, work area, and maven local repository we need a directory that is accessible to Tomcat for writing operations:

mkdir /var/lib/continuum
mkdir /var/lib/continuum/{conf,data,db,logs,m2}
chown -R tomcat6.tomcat6 /var/lib/continuum

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With the advent of the Web, search has become the prominent paradigm for information seeking, both across the online space and within enterprises. Search frameworks and components can be used to build search-based applications in diverse vertical fields. However, no precise engineering methods and approaches have been devised for this class of applications.

This tutorial, offered at the 10th International Conference on Web Engineering, presents the peculiarities of advanced Web search applications, describes some tools and techniques that can be exploited, and offers a methodological approach to development. The approach proposed in this tutorial is based on the paradigm of Model Driven Development (MDD), where models are the core artifacts of the application life-cycle and model transformations progressively refine models to achieve an executable version of the system. To cope with the process-intensive nature of the main interactions (i.e., content analysis, query management, etc.), we describe the use of Process Models (e.g., BPMN models). Indeed, search-based applications are considered as process- and content-intensive applications, due to the trends towards exploratory search and search as a process visions.

In the last few years non-relational data stores have drawn the attention of researchers and pratictioners. Their lack of fixed table schemas and the avoidance of join operators allow these tools to scale horizontally, storing huge amounts of data and providing high-performance access to it.

This class of databases (also known as NoSQL databases) often employs a distributed architecture with the data partitioned and redundantly replicated on several nodes, providing both scalability and fault tolerance.

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Subversion – also known as SVN – is a source version control system created by CollabNet Inc. and currently part of Apache Software Fundation. Today SVN is preferred to CVS since it supports many advanced features, like atomic commits (either all the changes – even spanning multiple files – are registered or the state of the repository is unchanged), tracking of copy/rename/delete operations (the history of a file is no longer lost when it’s copied or renamed) and support for “properties” (arbitrary metadata that can be attached to the files).

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