# nng_pull(7) Manual Page

## NAME

nng_pull - pull protocol

## SYNOPSIS

    #include <nng/protocol/pipeline0/pull.h>

## DESCRIPTION

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 puller 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.

## SEE ALSO

nng_pull_open(3), nng_push(7), nng(7),