Print

Print


Hi,

A few months ago, I tried setting up an xrootd redirector in front of
some xrootd proxy cache servers, and despite considerable to and fro
here from several people, we never managed to work out why it didn't
work. So, I dropped this as there were more pressing issues to deal
with at the time.

Now I'm back, and have a more directed question after more testing:

I have a node with xrootd 4.12.1 installed on it.

Things that work:
1. (xrootd+cmsd) redirector in front of (xrootd+cmsd) server attached
to local filesystem.
2. xrootd server using xrootdceph plugin attached to ceph cluster.
3. xrootd proxy cache in front of xrootd server from [2]

Things that don't work:
A. (xrootd+cmsd) redirector in front of [2]
B. (xrootd+cmsd) redirector in front of [3]

In both of the failing cases, the redirector complains that
[ERROR] Server responded with an error: [3011] No servers have read
access to the file (source)

which is obviously false, since I can copy happily from both the
server itself and the cache in front of it.

So, I think the problem here is somewhere in how the cmsds get
information about what files are available, and how this interacts
with the XrootdCeph plugin?
Obviously, the ceph instance has a *lot* of objects in it, and it's
not clear to me if there's something special that needs to be done to
help everything sync up.

[I also note that it's not clear to me how you configure a cmsd for an
xrootd server which is using a plugin for ofs. Since the cmsd is very
upset if I include ofs directives in the part of the config file it
can read, I assume it shouldn't be able to see those, so my config
file explicitly wraps them in an "if exec xrootd" block. Is that what
I should be doing?]

Any help appreciated,

Sam

########################################################################
Use REPLY-ALL to reply to list

To unsubscribe from the XROOTD-L list, click the following link:
https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-L&A=1