= nng_pull(7) // // Copyright 2018 Staysail Systems, Inc. // Copyright 2018 Capitar IT Group BV // // This document is supplied under the terms of the MIT License, a // copy of which should be located in the distribution where this // file was obtained (LICENSE.txt). A copy of the license may also be // found online at https://opensource.org/licenses/MIT. // == NAME nng_pull - pull protocol == SYNOPSIS [source,c] ---- #include ---- == DESCRIPTION (((protocol, _pull_))) The ((_pull_ protocol)) is one half of a ((pipeline pattern)). The other half is the xref:nng_push.7.adoc[_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 xref:nng_pull_open.3.adoc[`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 [.text-left] xref:nng_pull_open.3.adoc[nng_pull_open(3)], xref:nng_push.7.adoc[nng_push(7)], xref:nng.7.adoc[nng(7)],