| Title: | + OpenVMS Clusters - The best clusters in the world! + |
| Notice: | This conference is COMPANY CONFIDENTIAL. See #1.3 |
| Moderator: | PROXY::MOORE |
| Created: | Fri Aug 26 1988 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 5320 |
| Total number of notes: | 23384 |
A customer has a large FDDI Cluster consisting of 10 nodes with a
sizeable disk farm shadowed between two datacentres. He is using the
PREFER command to select particular nodes during mounting of shadowsets
to spread MSCP load to the lightest loaded CPU. This is fine but if
node reboots/crashes happen for any reason then of course the MSCP load
will shift to other available processors.
The question is can the PREFER command be used with the FORCE qualifier
to RELIABLY switch MSCP serving back to the customers preferred nodes
when they are available again?
Shaun Mc Caughan
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 5263.1 | Are you running Vanilla V6.2? | EVMS::PERCIVAL | OpenVMS Cluster Engineering | Fri Mar 21 1997 15:53 | 23 |
>PREFER command to select particular nodes during mounting of shadowsets
>to spread MSCP load to the lightest loaded CPU.
Presumably this means the cluster is a BRS one? You don't mention
which version of OpenVMS is running, which is fairly important in this
case. I would guess you are running V6.2 - in which case the
SET PREFER command will not always work as desired. For one such
cluster I wrote some simple routines which would perform several
retries - this worked quite sucessfully.
The failover logic, which this is all related to, had many changes
in V7.1 - and so should be far more reliable, though I have not
personally observed the behaviour on a V7.1 BRS cluster (if there are
many out there?). The new CLUSIO TIMA kit (I forget the exact name,
but another note in this conference refers to it) contains a lot of
backported fixes for V6.2. You might want to upgrade to this.
Hope this helps a little,
Regards,
Ian
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| 5263.2 | Yes BRS and 6.2 | CHEFS::MCCAUGHAN_S | Shaun Mc Caughan 842-3515 @BSO | Mon Mar 24 1997 09:31 | 7 |
Ian,
Thanks for your help, yes the configuration is a BRS one on OpenVMS
6.2. I will take a look at the TIMA kit you suggest.
Regards
Shaun
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