Langue: en

Version: 361943 (ubuntu - 24/10/10)

Section: 4 (Pilotes et protocoles réseau)


relup - Release upgrade file


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.


In a target system, the release upgrade file should be located in the OTP_ROOT/erts-EVsn/Vsn directory.

The relup file contains one single Erlang term, which defines the instructions used to upgrade the release. The file has the following syntax:

   [{UpFromVsn, Descr, Instructions}, ...],
   [{DownToVsn, Descr, Instructions}, ...]}.

Vsn = string() is the current version of the release. .br .br

UpFromVsn = string() is an earlier version of the release to upgrade from. .br .br

Descr = term() is a user defined parameter passed from the systools:make_relup/3,4 function. It will be used in the return value of release_handler:install_release/1,2. .br .br

Instructions is a list of low-level release upgrade instructions, see appup(4). .br .br 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. .br .br

DownToVsn = string() is an earlier version of the release to downgrade to. .br .br

When upgrading from UpFromVsn with release_handler:install_release/1,2, there does not have to be an exact match of versions, but UpFromVsn can be a sub-string of the current release version.


app(4), appup(4), rel(4), release_handler(3erl), systools(3erl)