Open Stack

I think that "extra_specs" in the database is too static, too hard to 
change.


In the case of eg. DRBD, where many nodes may provide some storage space, the 
list "replication_partners" is likely to change often, even if only newly 
added nodes have to be done[1]

This means that
  a) the admin has to add each node "manually"
  b) volume_type_extra_specs:value is a VARCHAR(255), which can only provide 
	 a few host names. (With FQDN even more so.)

What if the list of hosts would be matched by each one saying "I'm product XYZ 
version compat N-M" (eg. via get_volume_stats), and all nodes that report 
the same product with an overlapping version range are considered eligible 
for replication?


Furthermore, "replication_rpo_range" might depend on other circumstances 
too... if the network connection to the second site is heavily loaded, the 
RPO will vary, too - from a few seconds to a few hours.

So, should we announce a range of (0,7200)?


Ad 1: because Openstack sees by itself which nodes are available.


-- 
: Ing. Philipp Marek
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting                 http://www.linbit.com :

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