Present: Barry Blumenfeld, David Crooks, Alastair Dewhurst, Dave Dykstra, Costin Grigoras, Stefan Roiser (briefly)

Costin's squid monitor is now at http://cvmfsmon.cern.ch, based on MonALISA.

The monitor has two ways of getting data: installing an rpm now called "cvmfsmon" on the squid server machine which collects information about the host, and via SNMP just like MRTG does. Currently it includes 34 hosts via the rpm plus any squids that are registered in GOCDB or OIM. If any host has both the rpm and is registered, it doesn't use the SNMP interface because that's a duplication of information.

Data collected is about 60 parameters via SNMP and about 300 parameters from the data collection rpm. It uses the same resolution for both (every minute or two) but repeats the SNMP data when necessary because it is collected a little less often (every 5 minutes), by the wlcg-squid-monitor machine. After 2 months the data in the database gets converted to lower resolution so the space is reduced. Not all the parameters are easily accessible by the menu on the left, but they can all be browsed via the "MonaLisa GUI" link at the top. The "Repository status link" at the bottom of the left menu lists the current database size, about 73GB, and Costin doesn't expect it to grow much for the existing machines, just grow by the number of machines.

The general consensus among those present was that the SNMP data was the most vital and the only thing that WLCG sites should be officially requested to make available. While we welcome the contribution from Costin to the task force, the original agreement, to get sites to open port 3401 for monitoring, registering them in the GOCDB / OIM and provide a basic MRTG monitoring that shows the squid is up and functioning as intended (i.e. caching-related stuff) is unchanged and should proceed as planned.

The issue was raised over who is responsible for what types of problems; very likely the extra information should be the responsibility of the site and not the central monitoring team. Having said that, having the capability to collect the extra information may be useful and desired by some sites, so it may be good to have it available as an option if Costin is willing to continue to support it. We want to discourage people from only installing the rpm without enabling SNMP, because then it would not show up in MRTG.

The question was raised whether multiple squids on one machine is supported by the data collection rpm. Costin said no, but it would be easy to add.

The data collection rpm does not have a server name hardcoded. There is a MonALISA registry service hosted at CERN & Caltech, and the server registers itself there and the clients find it via the registry.

In the end this is what we agreed to do:

  1. Remove references to cvmfs monitoring and instead call it squid monitoring. The title on the website can be called "WLCG squid monitoring" instead of "CVMFS infrastructure monitoring". The rpm can be called "wlcgsquidmon" instead of "cvmfsmon".
  2. Remove direct access to http://cvmfsmon.cern.ch by renaming it to some obscure unpublished name and making it available via forwarding from http://wlcg-squid-monitor.cern.ch. Probably http://wlcg-squid-monitor.cern.ch/monalisa is a reasonable URL.
  3. Host the rpm in the same yum repository that the frontier-squid rpm is hosted in, at http://frontier.cern.ch/dist/rpms which includes a frontier-release rpm that defines a yum repository called cern-frontier.

Once that is all set up and working satisfactorily we can discuss further updating the existing online documentation to refer to the new monitor and talk about the option of using the wlcgsquidmon package to collect extra information. Perhaps we will then want to send out an all-WLCG announcement on the option.

-- Main.DaveDykstra - 28 Aug 2014

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Topic revision: r2 - 2014-08-29 - DaveDykstra
 
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