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<body class="manpage">
<div id="header">
<h1>
nn_reqrep(7) Manual Page
</h1>
<h2>NAME</h2>
<div class="sectionbody">
<p>nn_reqrep -
request/reply scalability protocol
</p>
</div>
</div>
<div id="content">
<div class="sect1">
<h2 id="_synopsis">SYNOPSIS</h2>
<div class="sectionbody">
<div class="paragraph"><p><strong>#include &lt;nanomsg/nn.h&gt;</strong></p></div>
<div class="paragraph"><p><strong>#include &lt;nanomsg/reqrep.h&gt;</strong></p></div>
</div>
</div>
<div class="sect1">
<h2 id="_description">DESCRIPTION</h2>
<div class="sectionbody">
<div class="paragraph"><p>This protocol is used to distribute the workload among multiple stateless
workers.</p></div>
<div class="paragraph"><p>Please note that request/reply applications should be stateless.</p></div>
<div class="paragraph"><p>It&#8217;s important to include all the information necessary to process the
request in the request itself, including information about the sender or
the originator of the request if this is necessary to respond to the request.</p></div>
<div class="paragraph"><p>Sender information cannot be retrieved from the underlying socket connection
since, firstly, transports like IPC may not have a firm notion of a message
origin. Secondly, transports that have some notion may not have a reliable one&#8201;&#8212;&#8201;a TCP disconnect may mean a new sender, or it may mean a temporary loss in
network connectivity.</p></div>
<div class="paragraph"><p>For this reason, sender information must be included by the application if
required. Allocating 6 randomly-generated bytes in the message for the lifetime
of the connection is sufficient for most purposes. For longer-lived
applications, an UUID is more suitable.</p></div>
<div class="sect2">
<h3 id="_socket_types">Socket Types</h3>
<div class="dlist"><dl>
<dt class="hdlist1">
NN_REQ
</dt>
<dd>
<p>
Used to implement the client application that sends requests and
receives replies.
</p>
</dd>
<dt class="hdlist1">
NN_REP
</dt>
<dd>
<p>
Used to implement the stateless worker that receives requests and sends
replies.
</p>
</dd>
</dl></div>
</div>
<div class="sect2">
<h3 id="_socket_options">Socket Options</h3>
<div class="dlist"><dl>
<dt class="hdlist1">
NN_REQ_RESEND_IVL
</dt>
<dd>
<p>
This option is defined on the full REQ socket. If reply is not received
in specified amount of milliseconds, the request will be automatically
resent. The type of this option is int. Default value is 60000 (1 minute).
</p>
</dd>
</dl></div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_see_also">SEE ALSO</h2>
<div class="sectionbody">
<div class="paragraph"><p><a href="nn_bus.7.html">nn_bus(7)</a>
<a href="nn_pubsub.7.html">nn_pubsub(7)</a>
<a href="nn_pipeline.7.html">nn_pipeline(7)</a>
<a href="nn_survey.7.html">nn_survey(7)</a>
<a href="nn_pair.7.html">nn_pair(7)</a>
<a href="nanomsg.7.html">nanomsg(7)</a></p></div>
</div>
</div>
<div class="sect1">
<h2 id="_authors">AUTHORS</h2>
<div class="sectionbody">
<div class="paragraph"><p>Martin Sustrik &lt;<a href="mailto:sustrik@250bpm.com">sustrik@250bpm.com</a>&gt;</p></div>
</div>
</div>
</div>
<div id="footnotes"><hr /></div>
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<div id="footer-text">
nanomsg 0.8-beta<br />
Last updated 2015-03-19 17:10:29 PDT
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