Introduction

This page describes the general scheme how xrootd software an configuration files are installed and distributed at SLAC.

Taylor

Taylor is used to distribute xrootd releases to the data servers and redirectors. Taylor runs daily on a server. The actions Taylor performs are configured by an options file:

/etc/taylor.opts

To see the taylor options for a particular server login to that server and run:

taylor -q opts

For more information about Taylor run man taylor.

To configuration option for xrootd for Taylor are:

xrootd=[Name],[restart]
cmsd=[restart]

The Name and restart option are optional. Name could be: glast, babar, atlas. The name is used by Taylor to determine which configuration file (xrootd.cf) to be used for a particular host.
The restart option is used by ranger. If it is set ranger will check every 15min if the daemon is running and if not try to restart it by executing "/opt/xrootd/prod/etc/StartXRD" (or StartCMS).

Distributing the xrootd tgz files.

Xrootd release are kept as tgz files in the distribution directory:

/afs/slac/package/xrd/distrib/xrootd/releases/

The tgz files contain the compiled xrootd release and the file names use the structure
xrootd-<releaseDate>_<arch>_dbg.tgz where <releaseDate> is the xrootd version and the format of the date is YYYYMMDD-HHMM and <arch> is the architecture the release was build for.

When Taylor runs on an xrootd server it finds all release that matches the architecture of the local host and if will untar the release to the /opt/xrootd directory if the release has not yet been installed. This means that all release that are available in the distribution directory are also available on an xrootd server.

Configuration files

To complete a xrootd installation the following configuration files are distributed by Taylor(for xrootd, cmsd and frm):

These files are located in the distribution directory:

/afs/slac/package/xrd/distrib/xrootd/local

The xrootd.cf and StartXRD.cf files depend on the xrootd cluster and therefore these files include the proper configuration file depending on the server host name or the taylor options for xrootd. For example the xrootd.cf
file might contain the lines:

%%if   ($ENV{HOSTSTEM} eq 'kan') || ($ENV{HOSTNAME} eq 'bbr-rdr03') || ($ENV{HOSTNAME} eq 'bbr-rdr04')
%%include /afs/slac/package/xrd/distrib/xrootd/local/xrootd-kan.cf
%%elif (Option->xrootd->has('glast'))
%%include /afs/slac/package/xrd/distrib/xrootd/local/xrootd-glast.cf
%%endif

Taylor is parsing this file and if the server host name used the stem kan (e.g. kan103) the xrootd-kan.cf file
would be copied to /opt/xrootd/prod/etc/xrootd.cf. If the taylor xrootd option for the server has the value glast (e.g.: xrootd=glast,restart), the xrootd-glast.cf file would be copied to /opt/xrootd/prod/etc/xrootd.cf.