Window Based Flow Control (Producer)
19.2.1. Window based flow control In a similar way to consumer window based flow control, HornetQ producers, by default, can only send messages to an address as long as they have sufficient credits to do so. The amount of credits required to send a message is given by the size of the message. As producers run low on credits they request more from the server, when the server sends them more credits they can send more messages. The amount of credits a producer requests in one go is known as the window size. The window size therefore determines the amount of bytes that can be in-flight at any one time before more need to be requested - this prevents the remoting connection from getting overloaded.