What is an active message?

Active message (AM) is a type of intermediate communication used in calculation, while a subroutine or computer program function can be performed by a completely different computer than where it is located. This type of message is such a basic format that it allows for greater use of the bandwidth width through standard Internet protocols (IP). It is also considered to be an asynchronous message transmission system, that it is immediately instead of waiting for a certain moment to synchronize with the program.

with the Active Messaging communication model most of the hardware level, where the hardware interacts with the operating system drivers. Since this lower level is normally reserved for the operation of the operating system, the messages are designed to be able to carry instructions to access the sequence of user functions of a higher level. Inside the AM header is the address of what the handler applies to. The handler is a special user -level instructions that allows you to process TThe messages were made by a processor. The body of the active message is therefore an argument of a function or date to which the calculation must act.

Due to the basic nature of the active message construction, it is able to pass on existing IP communication protocols of network communication. However, the primary difference is that it is immediately for admission, unlike the requirement of multi-phase, sent, receipt of acceptance, delivery method. In this way, the active message is considering a simply open pass pipe. The only constraints are the limitations of the physical network where the distance between the nodes can take into account the latency of the message.

The way the active message system works is the sender of the network filling with messages. There is no buffer the end of the reception, the only reaction to the AM is to briefly interrupt its calculation for the message service, catch a network message and continue its business. At the end of the senderThere is only a single time -leveling time where messages are held on the basis of whether the network reaches its limits. The questioning method keeps the cards in the network, so the system knows when to insert more messages. Active messages allow constant overlap of messages sent with calculations occurring on remote machines and also maintain coordinated.

While the active message method can be simple, it faces several problems with regard to implementation. Although it is such a primitive design, custom -designed interface drivers are often required to process messages for a computer system. Active messages are also designed for operation between computer nodes that all run the same program. In this way, instructed and accepted are specific to the program that is already running on the target computer.

Due to their nature, active messages have found extensive use in parallel computing environments such as one process application, more data (SPMD). These programs run on large networks of computer systems where active messages are used to transmit instructions and data between machines. Such distributed systems use the method to effectively process a huge amount of data that would otherwise take too long on one computer.