registry replication consistency in MSCS

Hi,
I'm using MSCS registry checkpointing to make sure my application data
written in registry will be available to other nodes when they become online.
I was wondering if the checkpoint operation is synchronous to the registry
write or is it possible that the registry write would be acknowledged but the
checkpoint would be delayed?
If the second option is possible than how can I guarentee that if a power
failure occurs right after the registry write was acknowledged that the
checkpoint was indeed written to quorum and would be available for the second
node when it becomes online?
Hi
Well, if your SAN and servers are not on UPS, and you have a power failure,
the OS might be in the middle of a write, resulting in a partial write. This
may lead to corruption in the registry or quorum drive.
If you have a cluster for high availability, you should have a reliable
power system, or at least a way to shut it down in an orderly fashion once
the UPS goes onto low power.
Unless you have an orderly server shutdown, don't expect anything to be 100%
once it comes up.
Why are you using the registry to persist data? Databases or XML files do
the job better.
Regards
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"smadar" <smadar@.discussions.microsoft.com> wrote in message
news:4BB152CC-4455-4CDF-91D2-B39EEF2D1D6D@.microsoft.com...
> Hi,
> I'm using MSCS registry checkpointing to make sure my application data
> written in registry will be available to other nodes when they become
> online.
> I was wondering if the checkpoint operation is synchronous to the registry
> write or is it possible that the registry write would be acknowledged but
> the
> checkpoint would be delayed?
> If the second option is possible than how can I guarentee that if a power
> failure occurs right after the registry write was acknowledged that the
> checkpoint was indeed written to quorum and would be available for the
> second
> node when it becomes online?
|||Hi,
Let me clarify my question:
My worries are not on the shutdown scenario, but on the behavior of the
checkpoint mechanism.
I'm using the win32 reg function: ZwSetValueKey (from my driver) to set a
key registered with a cluster resource.
If this call returns success can I assume that the data was already written
to a checkpoint on the quorum device? Is it synchronous to the registry write
or the quorum may be updated in a later time?
Thanks.
"Mike Epprecht (SQL MVP)" wrote:

> Hi
> Well, if your SAN and servers are not on UPS, and you have a power failure,
> the OS might be in the middle of a write, resulting in a partial write. This
> may lead to corruption in the registry or quorum drive.
> If you have a cluster for high availability, you should have a reliable
> power system, or at least a way to shut it down in an orderly fashion once
> the UPS goes onto low power.
> Unless you have an orderly server shutdown, don't expect anything to be 100%
> once it comes up.
> Why are you using the registry to persist data? Databases or XML files do
> the job better.
> Regards
> --
> Mike Epprecht, Microsoft SQL Server MVP
> Zurich, Switzerland
> IM: mike@.epprecht.net
> MVP Program: http://www.microsoft.com/mvp
> Blog: http://www.msmvps.com/epprecht/
> "smadar" <smadar@.discussions.microsoft.com> wrote in message
> news:4BB152CC-4455-4CDF-91D2-B39EEF2D1D6D@.microsoft.com...
>
>