View Source relup
Release upgrade file
Description
The release upgrade file describes how a release is upgraded in a running system.
This file is automatically generated by
systools:make_relup/3,4, using a release resource
file (.rel), application resource files (.app), and application upgrade
files (.appup) as input.
File Syntax
In a target system, the release upgrade file is to be located in directory
$ROOT/releases/Vsn.
The relup file contains one single Erlang term, which defines the instructions
used to upgrade the release. The file has the following syntax:
{Vsn,
[{UpFromVsn, Descr, Instructions}, ...],
[{DownToVsn, Descr, Instructions}, ...]}.Vsn = string()- Current release version.UpFromVsn = string()- Earlier version of the release to upgrade from.Descr = term()- A user-defined parameter passed from the functionsystools:make_relup/3,4. It is used in the return value ofrelease_handler:install_release/1,2.Instructions- A list of low-level release upgrade instructions, seeappup(4). 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.DownToVsn = string()- Earlier version of the release to downgrade to.