how to synchronize files or Dir between different remote hosts?

[张利高]

how to synchronize files or Dir between different remote hosts? 

if there are 2 hosts: s1 and s2, and ansible running at s3,

how to synchronize dirs on s1 and s2？

[Johannes Kastl]

First thought: Sync from s1 to s3 (put it somewhere on the controller)
and then sync this to s2.

Syncing directly via e.g. rsync might cause trouble with ssh-keys,
agents and stuff like that.

But I never had the need to actually do this, maybe someone else
already has...

Johannes