Home – Home – Jornals – Geography and natural resources 2016 number 6S

The field of service-oriented computations is actively developed in today’s world of information science. Tasks, which require use of multiple services, arise constantly. The combination of multiple services for the solution of a problem is called service composition. Dependencies between services can be usually described with the directed acyclic graph (DAG). There are a lot of ways to define service compositions; most of them use the graphic interface software or various markup standards. However, it is a common situation when it is convenient to define the composition of services as a piece of program code, at the same time the processing of intermediate service results and extraction of service dependencies graph should be available. The method of defining service compositions as the JavaScript programs was designed in ISDCT SB RAS in order to ex ecute service compositions. In order to define the composition, user calls services inside of the JavaScript code as regular functions. The intermediate processing of service results and building of complex control structures with standard programming language are available. During the processing and execution of scenarios the services dependencies graph is automatically built. The built graph can be later used, for example, for finding of optimal schedule for services execution in the distributed environment. The method of defining the services composition scenarios with JavaScript programs was successfully tested with real tasks and was integrated into the Portal of ISDCT SB RAS.