It seems to me that, in our environment, each AR server only connects to one listener (node) in the RAC. Different AR servers may be on a different node, but I don't know that I've see one AR server have its connections spread across multiple nodes in the RAC. I don't know if that's simply the way the Oracle client works, or if there are configuration options for the listeners that specify this behavior and would allow it to balance connections across multiple listeners, even when coming from the same client (AR server).
Either way, I don't think that having 3.2 GB per node is the same as having 9 GB on a single node. I think that spreading things out like this effectively gives you more CPU power (and redundancy - and this is the biggest benefit, IMO). It's probably better memory-wise than having a single instance of 3.2 GB, but because it caches actively used parts of the database in memory, that cache will essentially be duplicated on each of the three nodes, which reduces the overall memory efficiency (if that makes sense). Even so, unless you will have a very big implementation that is very actively used, I have a hard time seeing you needing that much memory on the DB. I suppose it primarily depends on how many concurrent users you will have and how large your database will become. Lyle From: Action Request System discussion list(ARSList) [mailto:[email protected]] On Behalf Of Chowdhury, Tauf Sent: Wednesday, April 27, 2011 8:54 AM To: [email protected] Subject: ITSM on Oracle RAC ** Guys, I need some input. Here is our architecture on RAC as explained to me: Remedy app servers connect to InstanceA. This is really an alias that pushes the DB connection to 3 nodes on the backend. Each node has SGA set to approx 3.2 GB In our initial sizing, we had requested 16GB of SGA on a standalone non-RAC DB. Looking at this configuration, and if you guys have any experience on RAC, is it really 9GB that is available to Remedy or does Remedy connect to just 1 node and effectively getting 3.2 GB of SGA? Sorry if I sound like a noob... Tauf Chowdhury | Forest Laboratories, Inc. Analyst, Service Management Informatics-Infrastructure Office: 631.858.7765 Mobile:646.483.2779 ________________________________ This e-mail and its attachments may contain Forest Laboratories, Inc. proprietary information that is privileged, confidential or subject to copyright belonging to Forest Laboratories, Inc. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, or the employee or agent responsible for delivering this e-mail to the intended recipient, you are hereby notified that any dissemination, distribution, copying or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. _attend WWRUG11 www.wwrug.com<http://www.wwrug.com> ARSlist: "Where the Answers Are"_ NOTICE: This email message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. _______________________________________________________________________________ UNSUBSCRIBE or access ARSlist Archives at www.arslist.org attend wwrug11 www.wwrug.com ARSList: "Where the Answers Are"
