Last Updated: February 25, 2016
· banjer

Mcollective mco Cheat Sheet

MCollective is a server orchestration tool that is built by Puppet Labs.

Finding/listing hosts

List all

mco find

With specific puppet classes

mco find --with-class apache
mco find --with-class postgres::server

With specific fact values

mco find --with-fact is_virtual=true --with-fact 'processorcount >= 12'


mco ping
You can use the same filters as shown above with mco find.

Ping all servers containing "test" in their name

mco ping -I /test/


Who's running apache?

mco service httpd status

Restart a service on all, but avoid thundering herd by splaying in batches, e.g. 3 at a time

mco service puppet restart --batch 3 --batch-sleep 3


mco process list elasticsearch
mco process list jboss
mco process list httpd


Create a file /tmp/fooj on test12

mco puppet resource file /tmp/fooj ensure=file mode=0440 owner=root -I test12

The filemgr command is probably more suited for file management tasks. See

Directory listing

mco rpc filemgr status dirlist=true file=/usr/local/java



sudo mco rpc yum install package=telnet
sudo mco rpc yum update package=rkhunter


If you care about the graphs displayed in summary, you'll need to set your putty encoding to utf-8 and use a font like DejaVu.

mco puppet summary
mco puppet count
mco puppet status

Invoke a puppet run on a specific server

mco puppet runonce -I test02

It's OK to do puppet runonce on multiple hosts. By default, puppet will splay its runs to avoid a thundering herd.