FreeLists / oracle-l / Re: oracle rac 10g and OS clusterware.

[Dan Norris <dannorris@xxxxxxxxxxxxx>]

Ujang,

Oracle Clusterware 10g will always handle node fencing (aka eviction) by 
rebooting one or more nodes. Oracle didn't have it's own cluster manager 
software for most platforms on 9i. So, if your customer was on a platform where 
Oracle didn't have a cluster manager of its own (it only had Linux and 
Windows), then building the RAC cluster would have required some 3rd party 
software. Some of the 3rd party cluster managers used different schemes to 
fence nodes from the cluster. Many of them used I/O fencing which was somewhat 
less disruptive in that it didn't require a node reboot, but required more 
proprietary interfaces to be used to access and manage storage. 

The answer to your question is that it depends. You will always have to have 
Oracle Clusterware if you're building a 10g cluster. However, if you 
additionally use a 3rd party clusterware (one that uses I/O fencing instead of 
reboots to handle node eviction), Oracle Clusterware will not handle cluster 
membership and therefore won't impose its "reboot the other node" scheme of 
node eviction. I should mention that I believe this is true in most cases, but 
not all cases. 

If you use just Oracle Clusterware (which is the only requirement and handles 
all cluster management needs albeit with using node reboots to evict them from 
the cluster), you'll be subject to node reboots if node eviction is required. 

See Kirk McGowan's post on Oracle Clusterware's node eviction methods at 
http://blogs.oracle.com/kmcgowan/2007/08/09#a13 for some additional insight. 

Dan

----- Original Message ----
From: Ujang Jaenudin <ujang.jaenudin@xxxxxxxxx>
To: Peter McLarty <peter.mclarty@xxxxxxxxxxxxxxxxxx>
Cc: oracle-l@xxxxxxxxxxxxx
Sent: Tuesday, December 4, 2007 9:08:07 PM
Subject: Re: oracle rac 10g and OS clusterware.


peter,

thanks for your sharing....

actually my customers said, that node eviction (by rebooting machine)
isn't acceptable due to it is not achieve HA it self.

they compare with the 9i RAC + OS cluster for almost they didn't have
any problem with node eviction (not as extreme as 10g RAC +
clusterware)

so what I'm asking is is the node eviction will be same? (reboot the
 machine)


regards
ujang


On 12/5/07, Peter McLarty <peter.mclarty@xxxxxxxxxxxxxxxxxx> wrote:
> Hi Ujang
>
> Yes you need clusterware, this controls many behaviours of the RAC
> cluster, it contains the OCR, it controls who gets evicted and forces
> the reboots of those evicted nodes when that happens, ther are a
 numbe
> of other important tasks that it also does.
>
> If you have an OS cluster package like Vertitas then you need to have
> clusterware and they link up to each other to mange the system as a
> whole.
>
> Yes you need a voting disk and OCR see above the OCR is part of
> clusterware
>
> The private network which is the cache interconnect is a requirement.
 If
> this fails the clusterware determines the host or hosts that will
 stay
> and be evicted in this failure. The network can be Ethernet, but
 check
> the install guide for your platform to see what is required.
>
> HTH
>
> Cheers
>
> --
> Peter McLarty <peter.mclarty@xxxxxxxxxxxxxxxxxx>
> Pacific DBMS Pty Ltd
>
>
> On Wed, 2007-12-05 at 07:49 +0700, Ujang Jaenudin wrote:
>
> > all,
> >
> > according to ML Note:220970.1 that whether use OS cluster or not,
 we
> > must install oracle clusterware for 10g RAC.
> > what I need other information are:
> > 1 . is it same the behavior between 10g rac which use OS cluster
 and
> > by purely oracle clusterware ?
> >      I mean the node eviction behavior....
> > 2. DO I need OCR and voting disk??
> > 3. is it network heartbeat (private network) still mandatory? and
> > should use ethernet??
> >
> > thanks for your sharing.............
> >
>
>
>


-- 
regards
ujang
jakarta - indonesia
http://ujang-id.blogspot.com
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