man relup (Fichiers spéciaux) - Release upgrade file

NAME

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 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:

{Vsn,
  [{UpFromVsn, Descr, Instructions}, ...],
  [{DownToVsn, Descr, Instructions}, ...]}.
*
Vsn = string() is the current version of the release.
*
UpFromVsn = string() is an earlier version of the release to upgrade from.
*
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.
*
Instructions is a list of low-level release upgrade instructions, see appup(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() is an earlier version of the release to downgrade to.

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.

SEE ALSO

AUTHOR

Gunilla Hugosson - support@erlang.ericsson.se