You are right Matthias, there are three different views of the cluster on the system, one for ODA (used at installation), one used by C3 (at command execution), and one used by ganglia (also at a usage level). In the OSCAR cluster, the one in ODA is the most important, because if there is an error with the other two you can rebuild their config files from the installer.
If the package writers for C3 and Ganglia were interested in doing so, it would be possible for them to pull their config information related to cluster structure from the ODA database directly, which would have some advantages in creating one unified (but fairly inaccessable to users) view of the cluster. I am concerned that this would have significant disadvantages over the current system in terms of performance and footprint, which is much more important. For example, there is currently no need (as far as i know) to have mysql running on the nodes after installation, which takes up a notable amount of memory. Accessing the database also takes cpu cycles, possibly network hits, and memory on the system depending on how you implemented the ODA queries. In the case of ganglia, this would get hit very, very often so performance is an issue. Also an issue with C3, but I think that is all on the head node so its not a big deal, since its not affecting user job performance. In short, unless you are modifying things by hand (which in an OSCAR mindset you shouldn't be) the config files shouldn't drift unless the power goes out while you are adding and removing nodes or something equally unlikely. Even then they are easily repaired, and in my mind there are performance and overhead hits from having C3 and ganglia query the database instead of a locally stored text config file. It just doesn't seem worth what seem to be mainly philosophical gains.. If it ain't broke, don't fix it, and all that... ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Oscar-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/oscar-devel
