explains the interesting output at https://bamboo.media.berkeley.edu/bamboo/browse/MYB-CLCMVPDEVDEPLOY-DEPLOYCALCENTRALDEV-218/log

since the run "sleep 20" is ran over the server.each loop, all nodes receive the sleep command (server x server) times.

Also, i think the sleep 20 is ran from ssh (so it's not exactly treated sequentially like a bash script). Maybe just the ruby sleep command will do.