From 8eb20d1fb0eb3a3b96d5e80e2e2617f893ef6986 Mon Sep 17 00:00:00 2001
From: Siri Hansen
Date: Thu, 20 Feb 2014 16:45:28 +0100
Subject: Add info about upgrade of core applications
In ref man for appup and in system documentation, design prinsiples,
add a warning related to upgrade when version of erts, kernel, stdlib
or sasl is changed. This will cause an emulator restart where new
version of emulator and core applications will startup together with
old versions of other applications. Care must be taken to avoid
problems due to backwards incompatibility.
---
system/doc/design_principles/release_handling.xml | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
(limited to 'system/doc/design_principles')
diff --git a/system/doc/design_principles/release_handling.xml b/system/doc/design_principles/release_handling.xml
index 2a5831b89f..ba8a88d1c2 100644
--- a/system/doc/design_principles/release_handling.xml
+++ b/system/doc/design_principles/release_handling.xml
@@ -4,7 +4,7 @@
- 20032013
+ 20032014
Ericsson AB. All Rights Reserved.
@@ -329,13 +329,26 @@
automatically ensured.
When the release handler encounters the instruction, it first
generates a temporary boot file, which starts the new versions
- of the emulator and the core applications. Then it shuts down
+ of the emulator and the core applications, and the old version
+ of all other applications. Then it shuts down
the current emulator by calling init:reboot(), see
init(3). All processes are terminated gracefully and
the system is rebooted by the heart program, using the
temporary boot file. After the reboot, the rest of the relup
instructions are executed. This is done as a part of the
temporary boot script.
+
+ Since this mechanism causes the new versions of the
+ emulator and core applications to run with the old version of
+ other applications during startup, extra care must be taken to
+ avoid incompatibility. Incompatible changes in the core
+ applications may in some situations be necessary. If possible,
+ such changes are preceded by deprecation over two major
+ releases before the actual change. To make sure your
+ application is not crashed by an incompatible change, always
+ remove any call to deprecated functions as soon as
+ possible.
+
An info report is written when the upgrade is completed. To
programatically find out if the upgrade is complete,
call release_handler:which_releases(current) and check
--
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