PULL protocol

The PULL protocol is one half of a pipeline pattern. The other half is the PUSH protocol.

In the pipeline pattern, pushers distribute messages to pullers. Each message sent by a pusher will be sent to one of its peer pullers, chosen in a round-robin fashion from the set of connected peers available for receiving. This property makes this pattern useful in load-balancing scenarios.

Socket Operations

The nng_pull0_open functions create a PULL socket. This socket may be used to receive messages, but is unable to send them. Attempts to send messages will result in NNG_ENOTSUP.

When receiving messages, the PULL protocol accepts messages as they arrive from peers. If two peers both have a message ready, the order in which messages are handled is undefined.

Protocol Versions

Only version 0 of this protocol is supported. (At the time of writing, no other versions of this protocol have been defined.)

Protocol Options

The PULL protocol has no protocol-specific options.

Protocol Headers

The PULL protocol has no protocol-specific headers.