18.10 Expanding Capacity

If your load-balancing and tuning efforts do not help increase performance to an acceptable level, your only remaining alternative is to expand system capacity. However, before you purchase additional hardware, you should carefully review the information you have collected concerning individual application and overall system-resource demand. With this information you should be able to determine which resource most needs expansion. If you expand a resource that is not constraining application performance, the affect will be minimal, and you will waste a considerable amount of money.