DOKK / manpages / debian 11 / erlang-manpages / relup.5.en
relup(5) Files relup(5)

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 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}, ...]}.
Current release version.
Earlier version of the release to upgrade from.
A user-defined parameter passed from the function systools:make_relup/3,4. It is used in the return value of release_handler:install_release/1,2.
A list of low-level release upgrade instructions, see appup(5). 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.
Earlier version of the release to downgrade to.

app(5), appup(5), rel(5), release_handler(3erl), systools(3erl)

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