Making a stateful service load balanced and redundant

I am writing an application which monitors a real-time stock market feed. Users submit a query to the service. When a stock meets the conditions of the query, the user is alerted.

I am trying to find a good way to load balance the application, and make it redundant.

Is there a st开发者_运维百科andard pattern for achieving active-active load balancing and redundancy?

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sticky sessions will accomplish the load balancing, redundancy is something that'll require more detail, unless your client can submit the same request to multiple sources.