6.3.2 SLA Defined for Case Study
For the definition of the SLA, if was first necessary to examine how Yahoo Mail actually
implements the delivery of the service using HTTP. The typical features that are offered in
the service needed to be assigned to service functions. The service functions created for the
case study were as follows:
6.3.2.1
Service Function
URL
Method
Login to Mail
http://login.yahoo.com/config/login?
POST
Read Mail
http://us.f1.mail.yahoo.com/ym/ShowLetter?
GET
Compose Mail
http://us.f1.mail.yahoo.com/ym/Compose?
GET
Delete Mail
http://us.f1.mail.yahoo.com/ym/ShowFolder?
POST
Send Mail
http://us.f1.mail.yahoo.com/ym/Compose?
POST
Search Mail Form
http://us.f1.mail.yahoo.com/ym/Search?
GET
Search Mail Results http://us.f1.mail.yahoo.com/ym/Search?
POST
Logout of Mail
http://us.f1.mail.yahoo.com/ym/Logout?
GET
Attach to Mail
http://us.f1.mail.yahoo.com/ym/Attachments?
GET
Table 9: Yahoo Mail Service Mappings
It is worth noting that the same URL and method can provide the different service functions.
The implication of this will be discussed later.
For the next step, parameters were assigned to each service mapping. For the purpose of the
case study, three derived performance parameters were created to monitor which consisted
of the following.
HEADER RESPONSE TIME
Response time in milliseconds to receive a reply header
from time that request is sent
ENTITY DOWNLOAD RATE Transfer rate in Kbps of reply body from service
ENTITY UPLOAD RATE
Transfer rate in Kbps of request body to service
Table 10: Table of Derived Parameters for Case Study
a
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