The use case is search heavy and the individual documents to be indexed are English text, about 5kb in size. Query requirements are expected to be 10-50 qps. After the initial offline load, the index will grow daily (but slowly). and will be used primarily for Google-like searches, matching multiple fields and retrieving snippets from 50 documents for each query. The system is mission critical but the expectation is that the system configuration may be tweaked after the initial deployment.