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Method R Discussion Group

I’m considering migrating to RAC for high availability but am concerned over performance implications. How can I ensure I get similar performance to my single-server architecture?

The first question to answer is "How much is HA worth to the business for the remaining life of the application?"

The answer does two things. First it gives you a good clue as to whether or not you should try to implement HA. Second, if you continue to investigate HA, then it tells you how much you can afford to spend ensuring similar performance.

If, for example, the app is going to live only for two more years and a perfectly working HA infrastructure will save the business $1M (i.e., the outages over the last two years resulted in a $750K loss), then convincing someone to spend $500K on HA is going to be difficult.

The most accurate (and expensive) method would be to replay and profile some or all of the recorded production transactions in the clustered environment. Then you can decide if you need to forget HA or

- optimize the existing transactions
- redistrubte the workload
- modify the hardware
- a combination of the above