There is currently no detailed documentation on the Ambari API. From the error message you posted it looks like the ganglia install failed. As to why it failed, the error message doesn’t give much info, you can try looking at the ambari agent logs to, hopefully, get a better picture. Just to be sure, you have set up passwordless ssh between the ambari server host and all other hosts in the cluster correct? Also have you turned off iptables on all of the hosts, as well as making sure that the s3 security is allowing communication on all ports for ambari and hadoop?