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Planning for High Availability

08.05.2003
Von Bob Zimmerman

Since support costs are dependent on the services provided and the infrastructure configuration, absolute price points are irrelevant. HA support should be priced at a multiple of the cost of a "standard" offering. The "Cost of Availability" graphic provides an estimated cost multiple for each level of availability and applies the cost multiple to calculate a "prevention cost per hour of downtime." The cost multiple provided is an average derived from cost estimates supplied by major services providers; the actual multiple is subject to change and varies by provider. The cost multiple would be multiplied by the cost of a standard HA of 99 percent to determine the total cost of the higher-availability solution. For example, if you historically spent $100,000 per year to achieve 99 percent availability (88 hours total downtime), plan to spend (290.7 x (0.011 x $100,000)) or almost $320,000 for "five nines" availability (downtime ...)

Summary

The high cost of downtime can be devastating to an enterprise. In the information-driven economy, downtime for any reason is unacceptable. In fact, availability and performance go hand in hand. Regardless of why -- application or database failure, system upgrade, operational error or just poor performance -- if a Web site or an application is slow in delivering requested information, it might as well be offline. The consequences -- lost data, lost customers, lost revenues -- can be devastating to an enterprise. Under these conditions, you have to maintain continuous uptime and predictable performance levels. And should an outage or disaster occur, quick recovery with minimal data loss is imperative. HA design and implementation can help avoid this.

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