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wiki:ponyland:guidelines [2019/04/25 15:23] (current)
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 +====== Usage guidelines ======
  
 +The Ponyland cluster is a powerful tool for getting your calculations done quickly, in particular if you use multiple cores or even multiple ponies simultaneously. This power, however, is not unlimited: if you use all cores on all ponies, you will slow down other jobs by other people that are running at that same time. 
 +
 +At some other clusters [[wiki:​ponyland:​SGE:​start|SGE]] is used to divide the resources. For Ponyland, however, we decided we do not want to force people into using SGE for a number of reasons, the most important ones being the desire to work from a local scratch disk for faster I/O, or in a more interactive session using //screen// or //tmux//.
 +
 +To make sure this freedom to avoid SGE does not mean everybody tries to use all of the ponies all the time, a number of guidelines have been composed:
 +
 +  - Non-SGE users always check ''​top''​ or ''​htop''​ (a little more visual) to see if a server has sufficient resources, and they monitor their processes as they run.
 +  - No single user takes all the resources of a single node (or all nodes). System load shouldn'​t exceed the number of cores (32 with hyperthreading).
 +  - SGE users keep within the SGE-constraints (i.e. submitting to the right queue, anything that is inherently multithreaded should go in '​multicore'​ queue instead of short/long, SGE queues have been set up in a way that no single person can claim all resources but SGE does little monitoring or enforcing).
 +  -  Communicate and coordinate with others running things ​ (our [[wiki:​IRC]] chat is a good medium for that ;) ).. even an SGE can't replace communication.
 +  - Never use Applejack for experiments. Applejack is reserved for [[wiki:​ponyland:​websites|websites and webdemos]].
wiki/ponyland/guidelines.txt ยท Last modified: 2019/04/25 15:23 (external edit)