Ksplice provides updates without reboots [LWN.net]

Ksplice provides updates without reboots

Posted Jul 14, 2009 6:55 UTC (Tue) by NAR (subscriber, #1313)
Parent article: Ksplice provides updates without reboots

While their exact plans are not yet clear, providing similar updates for enterprise kernels (RHEL and SUSE), but charging for those, would seem an obvious next step.

But would RedHat or Novell still support these hotpatched kernels? I think they should try to get money from RedHat and Novell directly...

Anyway, I think this whole ksplice thing is just a hack. A really clever hack that has the same effect on heterosexual male hackers that a half-nude Pamela Anderson picture - but still just a hack. I guess anyone really interested in high availability has to use some kind of hardware duplication in order to avoid harware failures. And if there's a spare wheel hardware available then there are cleaner ways to restart the service without noticable outage.

This ksplice thing is just a hack to make a kind of technology (monolithic application written in C) to be used in ways that it wasn't designed to be used. It can be used when there are no resources for a proper solution. However, there are technologies that are designed from the starting point to enable upgrades, etc. without downtime, for example Erlang with its OTP standard library.

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Ksplice provides updates without reboots

Posted Jul 14, 2009 9:38 UTC (Tue) by jcm (subscriber, #18262) [Link]

Meanwhile, in the real world, most people don't have the kind of money required to do 100% hardware duplication and even then that might not be easily possible for certain applications. Ksplice is only a hack insomuch as anything is a hack until it's proven itself - Linux was a hack once.

Ksplice provides updates without reboots

Posted Jul 14, 2009 18:47 UTC (Tue) by dlang (✭ supporter ✭, #313) [Link]

if businesses need continuous availability they are going to have redundant hardware.

it may be 100% duplicate (1-1 replication), or it may be a n+x style cluster of machines, but in either case they will have the redundant hardware so that they can survive hardware failing.

there are some companies that try to save a little money and make the backup boxes less powerful than the primary boxes, but they almost never do this after they have actually _used_ their backup boxes (people really don't care that you had a system failure and are running on a backup, they just want their stuff to work, and work fast)

Ksplice provides updates without reboots

Posted Jul 14, 2009 19:33 UTC (Tue) by NAR (subscriber, #1313) [Link]

Telephony exchange systems based on Erlang are used on all 5 continents (as far as I know) - that's real enough to me. On the other hand, if the target audience of KSplice Inc. can't afford spare hardware, will they spend money on the services of KSplice Inc?

Also there's the "false sense of security" expression thrown around when a not perfect solution is given to a problem - ksplice could give "false sense of reliability".