View source for SLOWCLOSE (JANUS DEFINE parameter)

<span class="pageSubtitle"><section begin="desc" />SLOWCLOSE mask &mdash; Don't be hasty closing connections<section end="desc" /></span>

<var>SLOWCLOSE</var> is a parameter on <var>[[JANUS DEFINE]]</var>, which defines and sets characteristics of a Janus port. 

The <var>SLOWCLOSE</var> parameter is followed by a bitmask that indicates the conditions under which <var class="product">[[Janus Web Server]]</var> is to perform a "slow" close of a connection with a browser. 

This parameter is useful for dealing with a bug in some browsers that sends an extra, junk, carriage-return and line-feed character after the contents of an HTTP POST. If these two extra characters are sent by the browser, and <var class="product">Janus Web Server</var> does not read them from TCP/IP (most of the time it will), then under certain conditions TCP/IP will discard outgoing data from <var class="product">Janus Web Server</var> when a normal close is done on the socket. To prevent losing this data in this case, <var class="product">Janus Web Server</var> must perform a more complex and so "slower" and, not incidentally, more expensive close for the connection. 

This parameter defaults to <code>X'01'</code>: <var class="product">Janus Web Server</var> will only perform "slow" close processing for a POST, and only when it has not already received an extra carriage-return and line-feed. 

While the default setting covers the known browser bug which only seems to occur on POSTs, <var>SLOWCLOSE</var> can be set to other values for other request types. These settings should only be necessary if browsers that send junk characters under other conditions are discovered:

<table class="list">
<tr><th>X'02'</th>
<td>Slow close for a GET that is followed by extra carriage-return and line-feed characters that are '''not''' read by the Web Server</td></tr>
<tr><th>X'04'</th>
<td>Slow close for a PUT that is followed by extra carriage-return and line-feed characters that are '''not''' read</td></tr>
<tr><th>X'10'</th>
<td>Slow close for a POST that is followed by extra carriage-return and line-feed characters, whether the characters are read by the Server or not</td></tr>
<tr><th>X'20'</th>
<td>Slow close for a GET that is followed by extra carriage-return and line-feed characters, whether the characters are read or not</td></tr>
<tr><th>X'40'</th>
<td>Slow close for a PUT that is followed by extra carriage-return and line-feed characters, whether the characters are read or not
</td></tr>
</table>

Valid only for <var>[[JANUS DEFINE#type|WEBSERV]]</var> ports.

==See also==

<ul>
<li>[[List of Janus commands]]
<li>[[JANUS DEFINE#parmlist|List of JANUS DEFINE parameters]]
</ul>

[[Category:JANUS DEFINE parameters|SLOWCLOSE]]