Christopher L Merrill
©2009 Web Performance, Inc.
v1.0 - Feb 18, 2009
Abstract: Initial load tests revealed that the capacity of a customized Microsoft Office SharePoint™ Server (MOSS) website cluster was far below the required level. With 200 concurrent users, average page durations ranged from 10-30 seconds. The cluster of 3 SharePoint™ servers and one SQL Server could serve only 4 pages/sec. Several iterations of load tests and tuning of the SharePoint™ configuration, custom code, and SQL Server resulted in steadily improving performance of the system. Limited only by bandwidth, the system can now support ~2000 users with average page durations of 2-5 seconds. At that level, system throughput is over 45 pages/sec with all servers running below 25% CPU utilization.
When we (Web Performance) first discussed the project with the customer (SHRM – Society for Human Resources Management), they expressed concerns over the performance of the system due to slow pages seen during system development. However, the website had not undergone any stress testing to date. The new site would be replacing the customers existing website – which is the primary interface between SHRM and their 250,000 members. The new site was scheduled to go live in 4 months and would bring a measurable benefit to the organization through improved work-flow and publishing features as well as an enhanced customer experience. However, the project leadership needed assurances that the new site would handle the anticipated load (1500 simultaneous users during peak hours).
The system, as tested, consists of a cluster of 4 SharePoint™ web servers, an application server and a database server. One of the SharePoint™ servers is reserved for search indexing. The application server is used for a few distinct functions, such as authentication. Each web server is an HP VL360 G5 with 2 quad-core processors and 16G of RAM. The database server runs on the same hardware with 32G of RAM. The servers sit behind a Cisco CSS load balancer on a DS3 line (45Mbps). The database storage is on an EMC Clarion CX-500 SAN and the web servers use only local disk storage. All servers run Windows Server 2003 64-bit Enterprise SP2. The web servers run Microsoft Office SharePoint™ 2007 64-bit. The SQL server runs SQL Server 2005 (roll-up 8).
Working with the customer, we proposed a handful of testcases to exercise ~500 pages in their site using our load testing software, Web Performance Load Tester™. This was a relatively small subset of the entire site, which is content-rich with over 15,000 articles. Considering a looming project deadline, this was agreed to be a reasonable compromise for getting rapid results. The result was 5 testcases that exercised various navigation paths through the site.