which set of nodes can be rebooted at the same time while avoiding
having both primary and secondary nodes being rebooted at the same time.
+For backends that support identifying the master node (currenlty
+RAPI and LUXI), the master node is scheduled as the last node
+in the last reboot group.
+
ALGORITHM FOR CALCULATING OFFLINE REBOOT GROUPS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BUGS
----
-The master node should be always the last node of the last group, or anyway
-somehow easily identifiable. Right now this is not done.
-
Offline nodes should be ignored.
If instances are online the tool should refuse to do offline rolling
EXAMPLE
-------
-Note that these examples may not for the latest version.
-
Offline Rolling node reboot output
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
With the default options, the program shows one reboot group per line as
a comma-separated list.
+::
- $ hroller
+ $ hroller -L
'Node Reboot Groups'
node1.example.com,node3.example.com,node5.example.com
node8.example.com,node6.example.com,node2.example.com