Unforeseen downtime: This is an unexpected lack of service, which is not at all desired by a quality service provider. During this period, the system is down due to a system failure. The service manager is responsible for monitoring the elements necessary to initiate the service. Special programming languages are used to represent a service level contract. The negotiating parties are brought together by protocols and negotiating languages that decide how they are engaged. Various languages were observed, such as bilateral protocol, WS agreement, QML Web Service Offering Language, SLAng, Web Service Level Agreement, Quality Objects, etc. We will try to give some brief descriptions of them and among them we describe in detail the agreement of WS and WSLA, which are widely used in research and industry. Suppliers often offer their services with a few models. A customer selects services based on the models provided by the service provider and uses a particular model to initiate a specific negotiation. Model-based negotiation is implemented by one or more of these linguistic frameworks. A comparison of administrative languages for the ALA is shown in Table 1. WS-Agreement: Open Grid Forum (OGF) [ 11 ] standardization set for the use of ALS in service-oriented environments.
This protocol is based on extended Markup Language (XML). This standard is used to specify and create service level agreements, widely known as Web Services Agreement Specifications (WS-Agreement). It allows service users to create dynamic ALS with service providers to acquire services. In addition, essential techniques are defined for the examination of the terms of an agreement and for the evaluation of guarantees whose reference is simone. In addition, the establishment of a mechanism for presenting the agreement is supported by this language. Typically, the service provider offers services in a model format, and service consumers follow the model to get an agreement. The model may vary depending on the ability to earn services to consumers based on their needs. This approach can be compared to a supermarket where customers choose the desired products from the variety of products according to their wishes.
The tables of the components of the WS agreement are presented [ 11 ] in Figure 5, where Negotiation Factory creates the negotiation process that implements the Port Type Of Negotiation. The bargaining instance represents the negotiation process that executes the type of volitional advertising and the main type of negotiation. The service evaluation manager only predicts the inoperative behavior of an assigned entire compound service. When ALS is known and all addictions to the lower level are resolved, it is designated as being fully specified [ 3 ]. SLA can be defined from different angles such as web services, networking, Internet, Data Management Center, etc. Although they vary from field to field, it is true that the overall functionality of all service level agreements is almost identical and therefore also applies to cloud computing. Software Quality Journal Band 12, Pages43-57 (2004) Quote this article In developing technology and business standards, IT is becoming a fundamental need for cloud computing that requires a clearly agreed ALS signed by the service consumer and linked by service providers like other service services mentioned above. An agreement is one of the most important parts of cloud computing. This is different from other procurement agreements and the process of this agreement is not sufficiently successful. Many researchers are trying to define a perfect ALS for cloud computing, but things are not that simple, because billions of money play a role in this area.