RAC Clustering [message #196015] |
Tue, 03 October 2006 13:23 |
RogerG
Messages: 1 Registered: October 2006 Location: Edison, nj
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Junior Member |
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Hi list,
I am working on a architecture which need High availability and Disaster recovery. SiteA and SiteB are about 200 miles distant, if the database on SiteA goes down SiteB should be up and running and in case of natural disasters if SiteA is not completely available SiteB should be up and running without any business interruption. Nodes on SiteA and SiteB will be connected to EMC Clariion, storage (EMC) will be available in both the locations.
I am considering ORACLE Extended RAC and these are my questions:
For Active/Active RAC both the instances on different nodes will be connected to one database on one EMC
Suppose the actual database is on EMC on SiteA and if the SiteA is completely not available then the database won't be available right? is it possible to have another exact mirror of the database on the other EMC using RAC?.
And also we are considering SAN TAP enabled cisco switches in case RAC has intolerable latency.
Please let me know.
Thanks in advance
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Re: RAC Clustering [message #201487 is a reply to message #196015] |
Sat, 04 November 2006 15:25 |
kimant
Messages: 201 Registered: August 2006 Location: Denmark
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Senior Member |
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Hi
You need to understand that a RAC database consists of the instances that are running it. No instance "owns" it.
So if SiteA goes away, the instance on SiteB still runs the database. Users that were connected to the instance on SiteA just needs to reconnect (which code can do automatically).
The two instances needs to access the same files on the same NAS, which means that You will probably need to figure out where You will place this physically. Placing it in SiteA, deems SiteB down if the network connection between SiteA and SiteB dies. Can You live with this?
And You need a VERY fast network connection between the two sites.
You might need another solution like a standby database, replication or many other solutions, depending on Your (business) needs.
Br
Kim
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