Red Hat Bugzilla – Bug 17781
Multiple redundant servers
Last modified: 2007-04-18 12:28:38 EDT
One feature that would be nice in the future is the ability to support
multiple redundancy, like TurboLinux Cluster Server does.
Thanks for your feedback. By this do you mean that:
1. If you failover to a system, and THAT system fails, it failsover to yet
another system? Some people call this a double failure and typically overkill
for HA software solutions, some call it a new single failure.
2. Or do you mean that more than one system can failover to a shared standby?
3. Something else entirely.
Piranha already does something similar to #1, in that if the original system
comes back online and the currently active system fails, it will fail back to
the original system.
In all of the above, we are considering the exmaples as possible architecture
options for future versions of the software.
I was referring to the way that TurboLinux handles multiple failover. When you
set up their clustering routers, you set up a "router pool". When the routers
first start up (or start up their clustering daemons), they check the status of
all the other routers in the pool, and if none of them declare themselves as
master, it will attach the virtual server IP's and declare itself as master.
After that, TurboLinux arbitrarily decides what priority the other servers will
have when failing over. I think right now it uses the alphabetical order of the
hostnames of the routers to determine what order the servers will failover to.
There's no reason this couldn't be assigned manually. When a router goes down,
and the services failover to another server, it becomes the master. If the
original router comes back up, it doesn't try to take the master status. This
obviously has its good and bad points, but its fairly flexible.
Got it. Thanks again.