Hi! To hunt down some performance problems on our AFS servers I started to integrate some metrics to our Ganglia monitoring system via a dirty hack; see for example <https://itp.tugraz.at/ganglia/?c=Theoretische%20Physik%20-%20Serverraum%20Chemie&h=faepsv00.tu-graz.ac.at>.
In that context 3 questions regarding nFEs and nCBs entered my mind: - What's the meaning of those? - I found some information about nFEs and nCBs in <https://www.openafs.org/pages/newsletter/newsletter-2013-03-volume004-issue05.html#openafs_tuning__part_i__fileservers__general>: "If nFEs or nCBs ever exceeds nblks, that is when the fileserver runs out of callbacks." I found that those metrices have a similar behaviour, but are usually not the same. Should I consider to store just "max(nFEs, nCBs)" or can I learn something from this difference? - Sometimes I see a spike in the usage of those values, e.g. <https://itp.tugraz.at/~ahi/privat/OpenAFS/graph_nCBs_2016-04-20.png> I can find out about volumes if I turn the debug level of the fileserver processes up 3 times, but this uses quite a bit of space to leave turned on permanently. Is there some easy accessible data on the (historic) distribution of callback on volumes? I'd rather prefer not to increase -cb, since this seems to be not our usual usage pattern. ---- Wed Apr 20 12:59:57 2016 We have run out of callback space; forcing callback revocation. This suggests the fileserver is configured with insufficient callbacks; you probably want to increase the -cb fileserver parameter (current setting: 1048576). The fileserver will continue to operate, but this may indicate a severe performance problem ---- You can find a bit more of my thougts in <https://itp.tugraz.at/~ahi/admin/AndrewFileSystem.html#org1c1731f>, but be aware - most of it is in german.. Best regards Andreas -- Andreas Hirczy <[email protected]> https://itp.tugraz.at/~ahi/ Graz University of Technology phone: +43/316/873- 8190 Institute of Theoretical and Computational Physics fax: +43/316/873-10 8190 Petersgasse 16, A-8010 Graz mobile: +43/664/859 23 57 _______________________________________________ OpenAFS-info mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-info
