Linked by Jordan Spencer Cunningham on Wed 30th Jun 2010 20:08 UTC
OSNews, Generic OSes I was lucky enough to receive an invitation to the HP Technology Forum 2010 via OSNews and just spent most of this last week in Las Vegas with five thousand other nerds of varying caliber. The tech forum is focused more on enterprise technology than that of the consumer, and-- let's face it-- even if any of us could afford a $30,000 rack of servers, most of us have little idea of what we'd do with so many resources except brag. Despite the focus on an area not quite as natural to OSNews and many of its readers, there was a plenitude of good and interesting information shared-- aside from that, the forum was simply fun. There were a few subjects that were especially eye-catching, though many of them not necessarily comprehensive enough to base an entire article on; thus this overview.
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RE[9]: Server Consolidation.
by akro on Sat 3rd Jul 2010 04:42 UTC in reply to "RE[8]: Server Consolidation. "
akro
Member since:
2005-07-06

Actually I would disagree that there are even a handful of live migratable services. I am racking my brain right now trying to think of anything stateful you can live migrate. Maybe RAC but that's really kinda cheating and connections must be reestablished....

I don't think your definition of live migrate is the same as mine.

For example I can RDP into a VM and run any app and move the VM to another machine and not only will my data in memory stay up but I won't even drop my connection.

We don't even lose a ping during a live migration 99 out of 100 times....

Reply Parent Score: 1

xiaokj Member since:
2005-06-30

Finally something concrete we can talk about.

I suppose the ability to not lose pings, and especially not drop connections, is just wonderful.

However, VMs themselves have stateful, so your first point is half answered.

I agree that it would be a great feat for pings and connections to be alive during the live migrations. However, as ventajov admitted, live migrations are usually done for slow deaths -- this means that live migrating services can just not accept connections for a while before completing. That way, services-level live migration will achieve the same level of continuity as compared to VM-level. i.e. abrupt deaths still cause loss of connection and some data loss.

Practically, services-level live migration should be inferior to VM-level ones because it is quite a bit harder to do without OS support. The inferiority, however, would be paid for by performance.

Reply Parent Score: 1