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2Can Tutorials - Web ServicesIntroductionToday, biological databases comprise large collections of data that are relatively difficult to maintain outside the centres and institutions that produce them. The EBI provides access to more than 200 such databases and to about 150 bioinformatic applications. These data and tools are mainly accessed using browser-based World Wide Web interfaces. When large amounts of data need to be retrieved and analysed, this often proves to be tedious and impractical. EBI also provides other mechanisms such as email batch job submissions, but this method lacks the interactivity of the web interfaces. Moreover, research is rarely completed just by retrieving or analyzing a particular nucleotide or protein sequence. Database information retrieval and analysis services have to be linked. For example, search results from one database can be used as the base of a search in another, the results of which are then analyzed. When performing these operations using a web browser, researchers are forced to repeat the tasks of searching, copying the results for subsequent searches to other databases, and again copy the results for analysis. Creating a local bioinformatics work environment is possible by downloading and installing the necessary database content and services (such as retrieval and analysis programs). This has the advantage that processes that otherwise require manual operations can be automated. However, the amount of disk space required to store biological sequence databases can be huge, often exceeding several terabytes, requiring several hours, if not days, to complete analysis. For this reason, creation of a local system is not a suitable option for most individual researchers or institutions. EBI Web Services On the basis of the above observations, the EBI has chosen to use the Web Services technology to provide fast and easy programmatic access to many of the services the EBI provides. All that is required at the user side is a lightweight program (written in java, perl etc) that communicates with the servers running at the EBI. These services have several advantages. As traditional web browsers cannot be used programmatically, these services provide an easy and flexible way to deal with repetitive tasks such as bulk submission with minimal intervention from the user. Web Services technology enables scientists to access EBI data and analysis applications as if they were installed on their laboratory computers. Similarly, it enables programmers to build complex applications without the need to install and maintain the databases and analysis tools. Moreover, Web Services provide easier integration and interoperability between bioinformatics applications and the data they require. |
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