nng_push(7)
===========
:doctype: manpage
:manmanual: nng
:mansource: nng
:icons: font
:source-highlighter: pygments
:copyright: Copyright 2017 Garrett D'Amore <garrett@damore.org> \
            Copyright 2017 Capitar IT Group BV <info@capitar.com> \
            This software 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_push - push protocol

SYNOPSIS
--------

[source,c]
----------
#include <nng/protocol/pipeline0/push.h>

int nng_push0_open(nng_socket *s);
----------

DESCRIPTION
-----------

The _nng_push_ protocol is one half of a pipeline pattern.  The
other side is the <<nng_pull.adoc#,nng_pull(7)>> 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_push0_open()` call creates a pusher socket.  This socket
may be used to send messages, but is unable to receive them.  Attempts
to receive messages will result in `NNG_ENOTSUP`.

Send operations will observe flow control (back-pressure), so that
only peers capable of accepting a message will be considered.  If no
peer is available to receive a message, then the send operation will
wait until one is available, or the operation times out.

NOTE: Although the pipeline protocol honors flow control, and attempts
to avoid dropping messages, no guarantee of delivery is made.  Furthermore,
as there is no capability for message acknowledgement, applications that
need reliable delivery are encouraged to consider the
<<nng_req.adoc#,nng_req(7)>> protocol instead.

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 _nng_push_ protocol has no protocol-specific options.

Protocol Headers
~~~~~~~~~~~~~~~~

The _nng_push_ protocol has no protocol-specific headers.
    
SEE ALSO
--------
<<nng.adoc#,nng(7)>>
<<nng_pull.adoc#,nng_pull(7)>>
<<nng_req.adoc#,nng_req(7)>>

COPYRIGHT
---------

Copyright 2017 mailto:garrett@damore.org[Garrett D'Amore] +
Copyright 2017 mailto:info@capitar.com[Capitar IT Group BV]

This document is supplied under the terms of the
https://opensource.org/licenses/LICENSE.txt[MIT License].
