From BioAssist
Revision as of 20:26, 15 April 2009 by Pieterb (Talk | contribs)

Jump to: navigation, search

The Token Pool Server (ToPoS) is a ReST webservice that supports distribution of large computational tasks on distributed systems, such as clusters, compute clouds, the Grid or processes on a super computer.


The current version of ToPoS is 3.0.


Older versions

ToPoS 1

The first version of ToPoS provided a simple counter which could be used to specify which job to run. The functionality provided was not enough for more sophisticated jobs which required multiple parameters to be set.

ToPoS 2

The second version of ToPoS was build as a virtual webdav server, which didn't actually hold files but provided a webdav interface to a database. Job tokens could be accessed as files, holding the parameters of a job as the file content. One of the strong points of ToPoS 2 was the ability to upload output and delete a token in one atomic operation. This ensures that no token is deleted unless the output is uploaded.

The performance of ToPoS 2 was not good enough to support 100k+ of tokens and the file-token model did not work out as expected. The problem there is that with the token files there are two places to put information: both in the file name and in the file content. To solve these problems a new version will be developed.

Future developments

  • Currently, the "Web interface" of ToPoS lacks "Go up one directory" navigation buttons. These should be added. --Jan Bot 23:03, 21 January 2009 (CET)
  • The $BASE/<realm>/pools/<pool>/ URL doesn't show the number of tokens in the tokens/ subdirectory, but the interface suggests that this information should be there. --Jan Bot 12:52, 22 January 2009 (CET)
  • Zou het handig zijn om een counter in ToPoS te implementeren om bij te houden hoe vaak een token is opgevraagd? We zouden dat eventueel kunnen gebruiken voor debugging zodat je kunt zien dat de nodes een bepaalde job gewoon niet aankunnen. --Jan Bot 16:38, 3 February 2009 (CET)
  • Opleuken van de interface dmv stylesheets.
  • Uniforme directory-listings.


A number of projects have used ToPoS to circumvent some of the problems related to the EGEE grid middleware.


ToPoS was used in combination with KCSmart to analyze copy number variation.