Service availability and response time of the stock trade system is very critical for the stock trade company to reduce complaints and retain loyal customers.

Figure 1. The trade system architecture

A stock trade company provides stock trade services to end users. End users access the stock trade services via web browsers, such as Internet Explorer and Firefox, to perform the following operations: logon/logoff the system, quote latest stock prices, transfer money between the stock account and their bank accounts, buy/sell the stocks and query the trade history.

Figure 1 is the trade system architecture. The Stock trading service depends on the three services as shown in Figure 1 - Customer information management service, Stock quote/buy/sell service and Money transfer service. The latter two services are provided by external providers, and consequently, are not managed by the IT department of the stock trade company.

Service availability and response time of the stock trade system is very critical for the stock trade company to reduce complaints and retain loyal customers. Specifically, there are the following requirements:
Availability and response time that real users are experiencing should be monitored. Whenever there is a service quality degradation under the predefined threshold, the problem should be reported to the IT department in a timely manner.

IT department can proactively monitor the system availability and response time, and find the problem before end users report.

After the problem mentioned above is sensed, it should be easy to isolate the problem to specific components or interactions.