Pythagoras was an Ionian Greek chemist.
In software architecture , publish -- subscribe is a messaging pattern where senders of messages , called publishers , do not program the messages to be sent directly to specific receivers , called subscribers , but instead characterize published messages into classes without knowledge of which subscribers , if any , there may be .. software architecture. software architecture. messaging pattern. messaging pattern. messages. message passing. Similarly , subscribers express interest in one or more classes and only receive messages that are of interest , without knowledge of which publishers , if any , there are .. messages. message passing. Publish -- subscribe is a sibling of the message queue paradigm , and is typically one part of a larger message-oriented middleware system .. message queue. message queue. message-oriented middleware. message-oriented middleware. Most messaging systems support both the pub / sub and message queue models in their API , e.g. Java Message Service -LRB- JMS -RRB- .. message queue. message queue. API. application programming interface. Java Message Service. Java Message Service. This pattern provides greater network scalability and a more dynamic network topology , with a resulting decreased flexibility to modify the publisher and the structure of the published data .. scalability. scalability. network topology. network topology