Multithreading support in CORE

Over the last year, we have worked towards increasing the amount of metadata and full-text content in the aggregation and also on improving the updating frequency of the system. However, increasing the volume of content created also a higher demand on the efficiency of processing, maintaining and exposing the content. In the last three months, we have been optimising the CORE system to improve the parallelisation of processes the CORE system performs. These are namely: downloading and parsing large metadata description files, downloading pdf files from multiple sources, converting pdf files to text, extracting citation information from full-texts, recognising citation targets, discovering semantically related resources, indexing. All these processes have been optimised to allow a relatively even distribution of load across many parallel threads. This task was in our view very important and required significant development effort, but was definitely worth it! A typical CORE repository processing activity will be in our hardware environment distributed among 144 threads (24 processors each with 6 cores). The optimised system enables us to continue adding more repositories into the CORE aggregation and will also helps us to keep content in CORE fresh.


How does CORE see my repository?

Since we first made CORE public, we’ve had a number of repository managers ask if we are harvesting their particular repository data. We’ve also sometimes come across issues harvesting content that we want to feedback to the repository manager (or other relevant staff). In order to be able to answer such questions, and to be transparent about what CORE is doing – what we have harvested, where we have encountered problems etc. we’ve now released a ‘Repository Analytics’ dashboard.


New CORE design

CORE received as part of the release of version 0.7 a brand new design ( The new design should be more user friendly. We have also added more information about CORE on the portal. We hope you will like it!

Best of both worlds

In the two previous blogs posts in this series (Finding fulltext and What does Google do?) I’ve described some of the challenges related to harvesting metadata and full text from institutional repositories. I’ve omitted some of the technical issues we’ve encountered (e.g. issues with OAI-PMH Resumption Tokens) as generally we’ve been able to work around these – although I may come back to these at some point in the future. Also worth a read is Nick Sheppard’s post on the UKCORR blog touching on some of these issues.


CORE organises a workshop on Mining Scientific Publications at JCDL 2012

The CORE team is organising a workshop collocated with JCDL 2012, a major conference in the field of digital libraries. Our proposal to organise the 1st International Workshop on Mining Scientific Publications was accepted. The aim of the workshop is to bring together researchers, digital library developers and practitioners from government and industry to address the current challenges in the field of mining scientific publications and building the necessary infrastructure to support this. The topics of the workshop are directly related to the work carried out in both SreviceCORE and DiggiCORE projects and are available on the workshop website.