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-rw-r--r--system/doc/system_principles/misc.xml198
-rw-r--r--system/doc/system_principles/part.xml1
-rw-r--r--system/doc/system_principles/versions.xml39
-rw-r--r--system/doc/system_principles/xmlfiles.mk3
4 files changed, 237 insertions, 4 deletions
diff --git a/system/doc/system_principles/misc.xml b/system/doc/system_principles/misc.xml
new file mode 100644
index 0000000000..dd6c2a1336
--- /dev/null
+++ b/system/doc/system_principles/misc.xml
@@ -0,0 +1,198 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+ <header>
+ <copyright>
+ <year>2018</year>
+ <holder>Ericsson AB. All Rights Reserved.</holder>
+ </copyright>
+ <legalnotice>
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ </legalnotice>
+
+ <title>Support, Compatibility, Deprecations, and Removal</title>
+ <prepared></prepared>
+ <responsible></responsible>
+ <docno></docno>
+ <approved></approved>
+ <checked></checked>
+ <date>2018-05-21</date>
+ <rev></rev>
+ <file>misc.xml</file>
+ </header>
+
+ <section>
+ <marker id="supported_releases"/>
+ <title>Supported Releases</title>
+ <p>
+ In general, bugs are only fixed on the latest
+ <seealso marker="versions#releases_and_patches">release</seealso>,
+ and new features are introduced in the upcoming release that is
+ under development. However, when we, due to internal reasons, fix
+ bugs on older releases, these will be available and announced as well.
+ </p>
+ <p>
+ Due to the above, pull requests are only accepted on the
+ <c>maint</c> and the <c>master</c> branches in our
+ <url href="https://github.com/erlang/otp">git repository</url>.
+ The <c>maint</c> branch contains changes planned for the next
+ <seealso marker="versions#releases_and_patches">maintenance patch package</seealso>
+ on the latest OTP release and the <c>master</c> branch contain
+ changes planned for the upcoming OTP release.
+ </p>
+ </section>
+
+ <section>
+ <marker id="compatibility"/>
+ <title>Compatibility</title>
+ <p>
+ We always strive to remain as compatible as possible
+ even in the cases where we give no compatibility guarantees.
+ </p>
+ <p>
+ Different parts of the system will be handled differently
+ regarding compatibility. The following items describe how
+ different parts of the system are handled.
+ </p>
+ <taglist>
+ <tag>Erlang Distribution</tag>
+ <item>
+ <p>
+ Erlang nodes can communicate across at least
+ two preceding and two subsequent releases.
+ </p>
+ </item>
+ <tag>Compiled BEAM Code, NIF Libraries and Drivers</tag>
+ <item>
+ <p>
+ Compiled code can be loaded on at least two
+ subsequent releases.
+ </p>
+ <p>
+ Loading on previous releases is <em>not</em> supported.
+ </p>
+ </item>
+ <tag>Compiled HiPE Code</tag>
+ <item>
+ <p>
+ Compiled HiPE code can be loaded on the exact same build
+ of ERTS that was used when compiling the code. It might
+ however work on other builds, the emulator verifies
+ checksums in order to determine if it can load the code
+ or not. Note that HiPE has some limitations. For more
+ information see the documentation of the
+ <seealso marker="hipe:HiPE_app">HiPE</seealso> application.
+ </p>
+ </item>
+ <tag>APIs</tag>
+ <item>
+ <p>Compatible between releases.</p>
+ </item>
+ <tag>Compiler Warnings</tag>
+ <item>
+ <p>New warnings may be issued between releases.</p>
+ </item>
+ <tag>Command Line Arguments</tag>
+ <item>
+ <p>Incompatible changes may occur between releases.</p>
+ </item>
+ <tag>OTP Build Procedures</tag>
+ <item><p>Incompatible changes may occur between releases.</p></item>
+ </taglist>
+ <p>
+ Under certain circumstances incompatible changes might be
+ introduced even in parts of the system that should be compatible
+ between releases. Things that might trigger incompatible changes
+ like this are:
+ </p>
+ <taglist>
+ <tag>Security Issues</tag>
+ <item>
+ <p>
+ It might be necessary to introduce incompatible changes
+ in order to solve a security issue. This kind of
+ incompatibility might occur in a patch.
+ </p>
+ </item>
+ <tag>Bug Fixes</tag>
+ <item>
+ <p>
+ We will not be bug-compatible. A bug fix might introduce
+ incompatible changes. This kind of incompatibility
+ might occur in a patch.
+ </p>
+ </item>
+ <tag>Severe Previous Design Issues</tag>
+ <item>
+ <p>
+ Some parts of OTP were designed a very long time ago and
+ did not necessarily take today's computing environments into
+ account. In some cases the consequences of those design
+ decisions are too severe. This may be performance wise,
+ scalability wise, etc. If we deem the consequences too
+ severe, we might introduce incompatible changes. This kind
+ of incompatibility will not be introduced in a patch, but
+ instead in the next release.
+ </p>
+ </item>
+ </taglist>
+ <p>
+ Peripheral, trace, and debug functionality is at greater
+ risk of being changed in an incompatible way than functionality
+ in the language itself and core libraries used during operation.
+ </p>
+ </section>
+
+ <section>
+ <marker id="deprecation"/>
+ <title>Deprecation</title>
+ <p>
+ Functionality is deprecated when new functionality is
+ introduced that is preferred to be used instead of the
+ old functionality that is being deprecated. The deprecation
+ does <em>not</em> imply removal of the functionality unless
+ an upcoming removal is explicitly stated in the deprecation.
+ </p>
+ <p>
+ Deprecated functionality will be documented as deprecated, and
+ compiler warnings will be issued, when appropriate, as
+ early as possible. That is, the new preferred functionality
+ will appear at the same time as the deprecation is issued.
+ A new deprecation will at least be announced in a release
+ note and the documentation.
+ </p>
+ </section>
+
+ <section>
+ <marker id="removal"/>
+ <title>Removal</title>
+ <p>
+ Legacy solutions may eventually need to be removed. In such
+ cases, they will be phased out on a long enough time period
+ to give users the time to adapt. Before removal of
+ functionality it will be deprecated at least during one
+ release with an explicit announcement about
+ the upcoming removal. A new deprecation will at least be
+ announced in a release note and the documentation.
+ </p>
+ <p>
+ Peripheral, trace, and debug functionality is at greater
+ risk of removal than functionality in the language itself
+ and core libraries used during operation.
+ </p>
+ </section>
+
+</chapter>
+
diff --git a/system/doc/system_principles/part.xml b/system/doc/system_principles/part.xml
index 1b87ecd350..9f70f40dfb 100644
--- a/system/doc/system_principles/part.xml
+++ b/system/doc/system_principles/part.xml
@@ -34,4 +34,5 @@
<xi:include href="create_target.xml"/>
<xi:include href="upgrade.xml"/>
<xi:include href="versions.xml"/>
+ <xi:include href="misc.xml"/>
</part>
diff --git a/system/doc/system_principles/versions.xml b/system/doc/system_principles/versions.xml
index b9f7fa4bf6..355c8fd2d5 100644
--- a/system/doc/system_principles/versions.xml
+++ b/system/doc/system_principles/versions.xml
@@ -32,9 +32,9 @@
<rev></rev>
<file>versions.xml</file>
</header>
- <marker id="versions section"></marker>
<section>
+ <marker id="versions section"></marker>
<title>OTP Version</title>
<p>As of OTP release 17, the OTP release number corresponds to
the major part of the OTP version. The OTP version as a concept was
@@ -136,8 +136,8 @@
</section>
<section>
- <title>Version Scheme</title>
<marker id="version_scheme"/>
+ <title>Version Scheme</title>
<note><p>The version scheme was changed as of OTP 17.0. This implies
that application versions used prior to OTP 17.0 do not adhere to this
version scheme. <seealso marker="#otp_17_0_app_versions">A list of
@@ -207,8 +207,41 @@
</section>
<section>
- <title>OTP 17.0 Application Versions</title>
+ <marker id="releases_and_patches"/>
+ <title>Releases and Patches</title>
+ <p>
+ When a new OTP release is released it will have an OTP
+ version on the form <c>&lt;Major&gt;.0</c> where the
+ major OTP version number equals the release number.
+ The major version number is increased one step since the
+ last major version. All other OTP versions with the same
+ major OTP version number are patches on that OTP release.
+ </p>
+ <p>
+ Patches are either released as maintenance patch packages
+ or emergency patch packages. The only difference is that
+ maintenance patch packages are planned and usually contain
+ more changes than emergency patch packages. Emergency patch
+ packages are released to solve one or more specific issues
+ when such are discovered.
+ </p>
+ <p>
+ The release of a maintenance patch package usually imply
+ an increase of the OTP <c>&lt;Minor&gt;</c> version while
+ the release of an emergency patch package usually imply an
+ increase of the OTP <c>&lt;Patch&gt;</c> version. This is
+ however not necessarily always the case since changes of
+ OTP versions are based on the actual changes in the code
+ and not based on whether the patch was planned or not.
+ For more information see the
+ <seealso marker="#version_scheme">Version Scheme</seealso>
+ section above.
+ </p>
+ </section>
+
+ <section>
<marker id="otp_17_0_app_versions"/>
+ <title>OTP 17.0 Application Versions</title>
<p>The following list details the application versions that
were part of OTP 17.0. If
the normal part of an application version number compares
diff --git a/system/doc/system_principles/xmlfiles.mk b/system/doc/system_principles/xmlfiles.mk
index 77d6747414..353c2c7f7f 100644
--- a/system/doc/system_principles/xmlfiles.mk
+++ b/system/doc/system_principles/xmlfiles.mk
@@ -21,7 +21,8 @@ SYSTEM_PRINCIPLES_CHAPTER_FILES = \
system_principles.xml \
error_logging.xml \
upgrade.xml \
- versions.xml
+ versions.xml \
+ misc.xml
SYSTEM_PRINCIPLES_CHAPTER_GEN_FILES = \
create_target.xml