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The SLA Evaluator gets
information about service performance from the SLA Monitor and
compares it to the agreed service level. Therefore the SLA Evaluator
maintains a list of active SLAs. SLA violations or fulfilment are
communicated via the Notification Broker.
Prerequisites
Software Installation
SLA Evaluator
API
Prerequisites
The SLA
Evaluator relies on the Microsoft .NET Framework 3.5. Necessary
components for a successful operation of the SLA Evaluator are a
deployed SLA Monitor and a deployed Notification Broker.
Installation
The SLA
Evaluator must be deployed on Microsoft Internet Information Service
(IIS) on Windows XP Professional, Windows Vista, Windows Server 2003
and Windows Server 2008.
The
addresses of an SLA Repository service and of the Notification
Broker that shall be used need to be specified in the Web.config
file as shown below:
<appSettings>
<add key="SLARepository.SLARepositoryService"
value="
http://localhost/SLARepository/SLARepositoryService.asmx" />
<add key="NotificationBroker"
value=" http://150.254.173.199:18001/" />
</appSettings>
Standard deployment leads to the service being available on the
local host under the following address:
http://localhost/SLAEvaluator/SLAEvaluator Service.asmx
SLA
Evaluator API
|
Method |
void SetSLA( string SLA_ID
) |
|
Arguments |
string SLA_ID
– The ID of an active SLA. |
|
Return Value[s] |
None |
|
Description |
The ID of an active SLA is passed to the SLA Evaluator. The
Evaluator then retrieves the SLA document from the SLA
Repository. |
|
Method |
void Evaluate( string SLA_ID, XmlElement
currentValues ) |
|
Arguments |
string SLA_ID
– The ID of the SLA contract that has to be consulted to see
if the current values are within the agreed Service Level
Objectives (SLOs). |
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XmlElement SLA_Status
– An XmlElement containing an array of measured values. The
elements of the array contain following information about the
measured value:
- name, type, unit, value |
|
Return Value[s] |
None
– Results of the evaluation are sent as notifications to the
Notification Broker. |
|
Description |
This method is called by the SLA Monitor. The current values
are compared to the SLOs of the SLA contract. In case of a SLA
violation or fulfillment, a notification is sent via the
Notification Broker. |
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