Билет 11

In indirect communication, no direct communication link exists between two processes. A message is stored in a mailbox. Two or more processes share a mailbox. a process sends or receives messages from a mailbox. A process checks a mailbox after a certain period of time whether any messages has come.In indirect communication, more than two processes can share a mailbox. No communication between two processes is possible if the processes do not have access to at least one common mailbox. Two processes can communicate through more than one mailbox.A process transfers a message to a mailbox using the send () function and retrieves a message from a mailbox using the receive () function. The syntax to implement the send function is:send (mailbox_name, message)The syntax to implement the receive function is:receive (mailbox_name, message)

Билет 12

The previous discussion concentrated primarily on the composition from relational data to XML data. In the case of shredded XML, we must first solve the opposite problem: How do we take XML data and represent it in a relational database? Stated another way, How do we encode an XML document as a set of relational entities, relations, and attributes?Creation of the Database when XML is being composed from relational data, we normally assume that the relational data already exists. That is, either the tables and schemas for the relational data have already been created for some other application, or else some application designer has expressly created tables for storing XML data—but in either case, the act of designing and installing the tables has been accomplished before we consider the details of how to map those tables to XML. With shredding, the opposite is usually the case. Initially we are presented with XML files, a DTD, or an XML schema, and we have to design and install the tables and columns that will hold the corresponding data.

Билет 13

The web services architecture provides a new way to think about and implement application-to-application integration and interoperability that makes the development platform irrelevant. Two applications, regardless of operating system, programming language, or any other technical implementation detail, communicate using XML messages over open Internet protocols such as HTTP or SMTP. The Simple Open Access Protocol (SOAP) is a specification that details how to encode that information and has become the messaging protocol of choice for Web services.Programming Web Services with SOAP is a detailed guide to using SOAP and other leading web services standards--WSDL (Web Service Description Language), and UDDI (Universal Description, Discovery, and Integration protocol). You'll learn the concepts of the web services architecture and get practical advice on building and deploying web services in the enterprise.

Билет 14

Autonomic Computing is an initiative started by IBM in 2001. Its ultimate aim is to develop computer systems capable of self-management, to overcome the rapidly growing complexity of computing systems management, and to reduce the barrier that that complexity poses to further growth."Autonomy-oriented computation" is paradigm proposed by Jiming Liu, in 2001 that uses artificial systems imitating social animals' collective behaviours to solve hard computational problems. For example, ant colony optimization could be studied in this paradigm.Self-management means different things in different fields:The number of computing devices in use is forecast to grow at 38% per annum and the average complexity of each is increasing . Currently this volume and complexity is managed by highly skilled humans; but the demand for skilled IT personnel is already outstripping supply, with labour costs exceeding equipment costs by a ratio of up to 18:1. Computing systems have brought great benefits of speed and automation but there is now an overwhelming economic need to automate their maintenance.