Developer

Dedicated to topics for software developers

Lock

Finding the key to your locks

Posted on 24 November 2016 by Thomas Green

Websites can be very useful for HPC to allow easier access. Recently we had an issue with a website we use and learned a few things on the way. Know your users A website has been running fine for a number of months – and building up a user base. However we recently hit an
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Image of restart icon

The art of restarting

Posted on 27 April 2016 by Thomas Green

Limits on runtimes Running jobs on a supercomputer can sometimes involve letting the job run for a long time. A long time in this instance is longer than the default expected maximum runtime for a particular type of job. At Cardiff we have 2 types of jobs which we have setup our supercomputer for. Serial
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Drop-in session at the Queen’s Buildings

Posted on 24 February 2016 by Andrew Williams

This Thursday (the 25th February), ARCCA will be holding a drop-in session in the Trevithick library room 1.15, from 2pm to 3.30pm. These drop-in sessions are an opportunity for the community to meet up with ARCCA in order to ask us questions, suggest ideas, or plead for help! As part of this initial session at
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Rose and Managing Workflows

Posted on 9 December 2015 by Andrew Williams

How would you like a tool that would allow you to: Write and maintain workflows more efficient and sophisticated than an existing job submission script. Create dependency trees of tasks that will run at the click of a button, with automatic optimisation so that multiple tasks may be run in parallel. Revision control your tasks
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Perls of wisdom

Posted on 9 November 2015 by Thomas Green

It has been a long summer and it is time again to create a little post for a recent encounter on our supercomputer. Errors in Perl Perl is a common language which is very common within the Genomic communnity. Recently we had an interesting Perl issue where a job would just run for its maximum
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United nations assembly.

Research seminar – Accelerating computing

Posted on 2 July 2015 by Thomas Green

Using accelerators such as GPUs and Intel Phi technologies are becoming a popular method to extend the performance of certains codes. ARCCA is holding a research seminar which covers this topic. All are welcome to attend, even if you are not planning to use the technologies its is great to see the cutting-edge research Cardiff
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Iceberg

Floating in numbers

Posted on 26 June 2015 by Thomas Green

Just like an iceberg, floating point numbers can have hidden danger lurking just under the surface. A recent email through a mailing list reminded me about the subtlties of handling floating point numbers. Floating point numbers are represented by mantissa*(base**exponent), see floating point numbers. There are many occassions where programmers may forget that floating point
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DRMAA

Working with DRMAA

Posted on 2 March 2015 by Thomas Green

Anyone who might have read earlier posts might have come across previous post on Galaxy. This used DRMAA to submit jobs when using a PBS Pro as a job scheduler. However recent issues whilst we upgraded our systems uncovered some unexpected issues with DRMAA. Going native with DRMAA First issue is with a feature of
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Docker logo

Docking to Docker

Posted on 2 February 2015 by Thomas Green

Another month has passed and we have been very busy in ARCCA at Cardiff University with installation of the new hardware and installing new services. These are a few of the reasons why updates in the past few weeks have been infrequent but as I keep saying to myself: Must do better… However recently we
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Bashing those script bugs

Posted on 20 November 2014 by Thomas Green

Recently we had a user report a problem where they had managed to start copying the complete filesystem of a compute node into their home directory. Fortunately for us we had setup quotas on our users home space so it stopped when it filled up their quota but it seemed it was all due to
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