When I first learned about high availability, it was something you provided by creating one or more copies of the operating environment on separate servers. Sometimes on different continents. If the server in Canada failed, the server in Ireland would take over.
Then I found out about Real Application Clusters. Wait, I asked myself, weren't applications invented for the sole purpose of field-testing the OS? Why do test programs need high availability? Haven't these people heard of Oracle Solaris Cluster?
Well, to my great disappointment there are plenty of different approaches to high availability. Just like there are plenty of different approaches to virtualization. And, as you might imagine, you can combine the two.
For instance, if you're going to build a cloud infrastructure using the virtualization capabilities in Oracle Solaris 11, you might as well allocate your network resources to the virtualized environment, as well. And so, you'd probably find yourself creating virtual switches, routers, cards, and what not. Well, what happens if all those virtual networks, which are really just one physical network, go down?
Bjoern Rost, Oracle ACE, provides a nice explanation of a Solaris feature that didn't get a lot of attention when it was released: Data Link Multipathing (DLMP) and DLMP aggregation. DLMP aggregation allows you to combine virtual network interfaces from different physical network interfaces into high availability clusters. You can also use these clusters to improve load balancing, as Bjoern explains in his blog post.
Orgad likes DLMP, too. So much, in fact, that he took a break from reconfiguring the International Space Station so his kids could control it from their XBox, and wrote an article explaining how to apply DLMP to a virtual network. Two articles, in fact.
by Orgad Kimchi
How to combine virtual NICs from different physical NICS into a DLMP aggregation assigned to a zone, and configure the aggregation to provide failover for the zone, using Oracle Solaris 11.
by Orgad Kimchi
You can give an Oracle Solaris 11 zone exclusive access to a physical NIC. Although that approach can ensure that particular zone has full access the entire bandwidth of the NIC, it does leave NIC and the entire network exposed to security breaches. Unless you use DLMP's Link Protection capability. Orgad explains how to do that, as well as enabling resource management for your Oracle Solaris 11 virtual network, improving the availability of an NFS server, and more.
About the Photograph
Lou Ordorica and I took off early a few weeks ago to get in some twisties before the crowds showed up. We stopped at The Last Shot on the Peak to Peak highway to grab a late breakfast/early lunch. While we were there a few more bikes showed up.