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Squids

A number of Frontier Squids are operated as caching infrastructure for CVMFS clients.

With the migration to EL9, the hostnames of the squids are not used directly anymore but clients should use primarily alies like CNAMES or load balancer cluster. This allows us to move more easy squids from production into maintenance without inetrfering with client configurations.

Load Balancing Squid Clusters

Per VO or use case, a load balancing cluster has been set up (where the individual clusters can overlap with repect to the actual squids they cover).

I.e., for VOs clusters are available DESY internal as

For generic use cases clusters

  • generic
    • load balancing cluster squid-grid.desy.de:3128
    • aliases squid-grid0{1,2,3,4,5,6}.desy.de
  • NAF
    • load balancing cluster squid-naf.desy.de:3128
    • aliases squid-naf0{1,2,3}.desy.de
  • Desktops:
    • load balancing cluster: squid-desktop.desy.de:3128

and VO specific aliases & clusters

  • ATLAS
    • load balancing cluster squid-atlas.desy.de:3128
    • aliases squid-atlas0{1,2,3}.desy.de
  • Belle II
    • load balancing cluster squid-belle.desy.de:3128
    • aliases squid-belle0{1,2,3}.desy.de
  • CMS
    • load balancing cluster squid-cms.desy.de:3128
    • aliases squid-cms0{1,2,3}.desy.de

For generic use cases clusters

Please get in contact with DESY IT/Grid, if you plan to use on of the squids for CVMFS, so that we can assist you to set up your configuration in Puppet appropriately

Squid Set Ups

The squids are set up as virtual machines balanced over a number of hypervisors. To avoid cross-feed between caches and logging, each squid has two disks attached, one for the OS and one for logging, and one disk for the squid cache as such.

Upstream Configurations

Update the squids in GOC DB https://goc.egi.eu/portal/index.php. Currently, we have setgrid squid CNAMEs as aliases

  • squid-grid0{1,2,3,4}.desy.de

as Dave suggsted not to use load balancers but go only for direct squids.

To balance squid access, CNAMEs are attached to each squid DNS entry.

ATLAS

Set the ATLAS squid CNAMEs

  • squid-atlas0{1,2,3}.desy.de

in the ATLAS CRIC site sttings https://atlas-cric.cern.ch/core/rcsite/main/DESY-HH/

which then should propagate down to the site overview https://atlas-cric.cern.ch/core/rcsite/main/DESY-HH/ and into CVMFS /cvmfs/atlas.cern.ch/repo/sw/local/etc/cric_sites.json for the pilots

Belle II

Belle has there configs in belle.cern.ch and belle.kek.jp

CMS

Open a ticket that CMS can update their site config, which also will get propagated down CVMFS.

  • squid-cms0{1,2,3}.desy.de