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ClusterShell

Configuration

Grendel can be used as a group source for clush leveraging tags to filter nodes

See configs/clush.grendel.conf.sample for an example clustershell config. The jq should be talored to your compute environment, by default only grendel nodes which start with cpn will be returned

Usage

-g can be used with a tag name

you can also use -w with the @ prefix, ie: -w @<tag>

$ clush -s grendel -b -g rack=f01 -- echo test
---------------
cpn-f01-[04-07,09-12,14-17,22-25,31,33] (18)
---------------
test

multiple tags can be specified with comma separation

$ clush -s grendel -b -g rack=f01,rack=f02 -- echo test
---------------
cpn-f[01-02]-[04-07,09-12,14-17,22-25,31,33] (36)
---------------
test

tags can be excluded from the list with -X <tag>

$ clush -s grendel -b -g rack=f01,rack=f02 -X gpu -- echo test
---------------
cpn-f[01-02]-[04-07,09-12,14-17,22-25] (32)
---------------
test

trying to filter by a tag which doesn't exist will display the grendel API error

$ clush -s grendel -b -g randomtag -- echo test
[2026-05-01T11:51:39-04:00] FATAL CLI: API Error: status=500 title=Error detail=failed to filter nodes
Usage: clush [options] command

clush: error: No node to run on.

excluding an invalid tag will display the error and continue as if -X <tag> wasn't passed

$ clush -s grendel -b -g rack=f01 -X randomtag -- echo test
[2026-05-01T11:53:23-04:00] FATAL CLI: API Error: status=500 title=Error detail=failed to filter nodes
---------------
cpn-f01-[04-07,09-12,14-17,22-25,31,33] (18)
---------------
test