<?xml version="1.0" encoding="latin1" ?> <!DOCTYPE fileref SYSTEM "fileref.dtd"> <fileref> <header> <copyright> <year>1997</year> <year>2011</year> <holder>Ericsson AB, All Rights Reserved</holder> </copyright> <legalnotice> The contents of this file are subject to the Erlang Public License, Version 1.1, (the "License"); you may not use this file except in compliance with the License. You should have received a copy of the Erlang Public License along with this software. If not, it can be retrieved online at http://www.erlang.org/. Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. The Initial Developer of the Original Code is Ericsson AB. </legalnotice> <title>relup</title> <prepared></prepared> <docno></docno> <date></date> <rev></rev> </header> <file>relup</file> <filesummary>Release upgrade file</filesummary> <description> <p>The <em>release upgrade file</em> describes how a release is upgraded in a running system.</p> <p>This file is automatically generated by <c>systools:make_relup/3,4</c>, using a release resource file (<c>.rel</c>), application resource files (<c>.app</c>) and application upgrade files (<c>.appup</c>) as input.</p> </description> <section> <title>FILE SYNTAX</title> <p>In a target system, the release upgrade file should be located in the <c>OTP_ROOT/erts-EVsn/Vsn</c> directory.</p> <p>The <c>relup</c> file contains one single Erlang term, which defines the instructions used to upgrade the release. The file has the following syntax:</p> <code type="none"> {Vsn, [{UpFromVsn, Descr, Instructions}, ...], [{DownToVsn, Descr, Instructions}, ...]}. </code> <list type="bulleted"> <item> <p><c>Vsn = string()</c> is the current version of the release.</p> </item> <item> <p><c>UpFromVsn = string()</c> is an earlier version of the release to upgrade from.</p> </item> <item> <p><c>Descr = term()</c> is a user defined parameter passed from the <c>systools:make_relup/3,4</c> function. It will be used in the return value of <c>release_handler:install_release/1,2</c>.</p> </item> <item> <p><c>Instructions</c> is a list of low-level release upgrade instructions, see <c>appup(4)</c>.</p> <p>It consists of the release upgrade instructions from the respective application upgrade files (high-level instructions are translated to low-level instructions), in the same order as in the start script.</p> </item> <item> <p><c>DownToVsn = string()</c> is an earlier version of the release to downgrade to.</p> </item> </list> <p>When upgrading from <c>UpFromVsn</c> with <c>release_handler:install_release/1,2</c>, there does not have to be an exact match of versions, but <c>UpFromVsn</c> can be a sub-string of the current release version.</p> </section> <section> <title>SEE ALSO</title> <p>app(4), appup(4), rel(4), release_handler(3), systools(3)</p> </section> </fileref>