Hardware Sizing Worksheet

Use the Hardware Sizing worksheet prior to testing in order to estimate the hardware requirements for a production web site. After completing the test, use this worksheet as input to the Capacity Planning worksheet, which is included in this appendix. See the case study in Chapter 14, as well as Chapter 15, for examples using this worksheet.

Input Data

	Input Data	Source	Your Data
1.	Concurrent users	Capacity Sizing worksheet, line 12
2.	Throughput: page rate	Capacity Sizing worksheet, line 13
3.	Throughput: requests	Capacity Sizing worksheet, line 14
4.	Response time	Marketing
5.	Headroom factor	Marketing/planning
6.	Estimated throughput supported on your selected hardware	Hardware/application server vendor

Calculating Hardware Requirement Estimate (Pre-Test)

	Calculated Data	Calculation	Total
7.	Concurrent users (with headroom)	Concurrent users + Concurrent users / (100 / Headroom “ 1) Line 1 + Line 1 / (100 / Line 5 “ 1)
8.	Throughput requirement (with headroom): page rate	Throughput + Throughput / (100 / Headroom “ 1) Line 2 + Line 2 / (100 / Line 5 “ 1)
9.	Throughput requirement (with headroom): requests	Throughput + Throughput / (100 / Headroom “ 1) Line 3 + Line 3 / (100 / Line 5 “ 1)
10.	Application servers required	Throughput requirement (dynamic requests) / Estimated throughput for your hardware + 1 (for maintenance) Line 8 / Line 6 + 1