Tools/Manuals/TS120

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Back to Administration FAQ

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How to run CEs with the Torque/Maui manager installed on a different host

The YAIM documentation describes how to configure a CE that is not also the batch server: in such cases the relevant utils node type needs to be configured along with the CE itself.

Notes regarding Maui

Even if Maui is not running on the CE, the CE still needs the Maui client to get scheduler details to publish in the BDII. The client is invoked at the end of a command chain starting with this script:

/opt/glite/etc/gip/plugin/glite-info-dynamic-scheduler-wrapper

The maui.cfg file on the CE then just needs to specify the server host (and possibly the port).

Warnings

• By default the Maui client needs the exact same build of the binaries as on your Maui server, so it is best to copy them. The same version but a different build by default is not close enough, but see below.
• You need to give accounts edguser and ldap the ADMIN3 privilege on the Maui server:

• Those accounts must have the same UID/GID on the CE and the server.
• In maui.cfg on the server add this line:

ADMIN3 edguser ldap

Those accounts are used by gLite and EMI versions of the BDII, respectively.

How to make different Maui builds work together

The heart of the following recipe was provided by Stefan Freitag at the Grid @ Robotics Research Institute of the TU Dortmund and posted here. In short:

1. Extract the secret key from the MAUI server:

     strings /usr/sbin/maui | egrep '^[0-9]{5,6}$'

There may be more than one 5- or 6-digit number in the binary, in which case each can be tried until the right one is found. Record the correct number like in this example:

     echo 123456 > /var/spool/maui/maui.key

The key is wrong if you get a response as shown here:

     # /usr/bin/diagnose -g --keyfile=/var/spool/maui/maui.key
     ERROR:    lost connection to server
     ERROR:    cannot request service (status)

2. Copy the MAUI key to the target machine:

     scp /var/spool/maui/maui.key TARGET_MACHINE:/var/spool/maui/maui.key

2. On the target machine replace /usr/bin/diagnose:

     cat > /usr/bin/diagnose.hack << 'EOF'
     #!/bin/sh
     exec /usr/bin/diagnose.real --keyfile=/var/spool/maui/maui.key "$@"
     EOF

     chmod 755 /usr/bin/diagnose.hack
     chmod 644 /var/spool/maui/maui.key
     ln /usr/bin/diagnose /usr/bin/diagnose.real
     mv /usr/bin/diagnose.hack /usr/bin/diagnose

Or create a similar diagnose script in another directory (e.g. /usr/local/bin) and ensure the info provider uses that version.