Hi Brian, There is a peering mechanism but you will have to use subordinates in the context of meta-managers to make it work. The reason is that the meta-manager is the top-most manager and it can't subscribe anyone else. This may change, but for now, this is the way it is. So, follow the following procedure: 1) Assume you have a meta-managers (MM) A and B (one for region A and one for B). 2) On A run an xrootd/cmsd pair we will call A'. 3) In A' config file, insert (at least) the following directives: all.role peer all.manager peer B xrootd.redirect A all xrootd.redirect A / Then A' will subscribe to B as a peer. When the file cannot be found using B, the client will be redirected to A' which will redirect the client to A, the alternate meta-manager. Please note there is a difference in roles between peer and 'peer manager' where the former is a stand-alone server while the latter is a member of a cluster. The role table describes this: http://xrootd.org/doc/dev/cms_config.htm#_Toc295744040 The setup is complimentary. So, you could have configured this in the opposite direction (B' is a peer of B which redirects to A). It depends on who needs to be in control of the peering arrangement. Mind you, the peering was used long time ago to integrate Castor at CERN. We have not had much experience with peering beyond that and peering is no longer used for Castor. However, it should work and we'll be happy to address any problems. Once we get a better feel for this, it's likely we will incorporate peering directly into the meta-manager to make life simpler. Andy -----Original Message----- From: Brian Bockelman Sent: Thursday, August 18, 2011 8:16 AM To: xrootd-dev Subject: Peering redirectors Hi folks, Currently, CMS has two regional redirectors - US and EU. Both are starting to attain a critical mass of sites, and we'd like them to peer together. By "peering", I mean that clients can get a cross-region redirect, *but* this only happens if a file is unavailable in the region (unavailable implies that either all known servers respond in the negative, or a timeout occurs). I know there is some peering mechanisms pre-existing, but I can't make enough sense of the documentation to tell if this is what I want. If it is a match, what should I add to the configuration file? Thanks, Brian