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<!DOCTYPE chapter SYSTEM "chapter.dtd">
<chapter>
<header>
<copyright>
<year>2014</year><year>2016</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.
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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>Versions</title>
<prepared></prepared>
<responsible></responsible>
<docno></docno>
<approved></approved>
<checked></checked>
<date>2014-02-19</date>
<rev></rev>
<file>versions.xml</file>
</header>
<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
introduced in OTP 17. The version scheme used is described in detail in
<seealso marker="#version_scheme">Version Scheme</seealso>.</p>
<p>OTP of a specific version is a set of applications of specific
versions. The application versions identified by an OTP version
corresponds to application versions that have been tested together
by the Erlang/OTP team at Ericsson AB. An OTP system can, however, be
put together with applications from different OTP versions. Such a
combination of application versions has not been tested by the
Erlang/OTP team. It is therefore <em>always preferred to use OTP
applications from one single OTP version</em>.</p>
<p>Release candidates have an <c>-rc<N></c>
suffix. The suffix <c>-rc0</c> is used during development up to
the first release candidate.</p>
<section>
<title>Retrieving Current OTP Version</title>
<p>In an OTP source code tree, the OTP version can be read from
the text file <c><OTP source root>/OTP_VERSION</c>. The
absolute path to the file can be constructed by calling
<c>filename:join([</c><seealso marker="kernel:code#root_dir/0"><c>code:root_dir()</c></seealso><c>, "OTP_VERSION"])</c>.</p>
<p>In an installed OTP development system, the OTP version can be read
from the text file <c><OTP installation root>/releases/<OTP release number>/OTP_VERSION</c>.
The absolute path to the file can by constructed by calling
<c>filename:join([</c><seealso marker="kernel:code#root_dir/0"><c>code:root_dir()</c></seealso><c>, "releases", </c><seealso marker="erts:erlang#system_info_otp_release"><c>erlang:system_info(otp_release)</c></seealso><c>, "OTP_VERSION"]).</c></p>
<p>If the version read from the <c>OTP_VERSION</c> file in a
development system has a <c>**</c> suffix, the system has been
patched using the
<seealso marker="../installation_guide/OTP-PATCH-APPLY"><c>otp_patch_apply</c></seealso>
tool. In this case, the system consists of application
versions from multiple OTP versions. The version preceding the <c>**</c>
suffix corresponds to the OTP version of the base system that
has been patched. Notice that if a development system is updated by
other means than <c>otp_patch_apply</c>, the file <c>OTP_VERSION</c>
can identify an incorrect OTP version.</p>
<p>No <c>OTP_VERSION</c> file is placed in a
<seealso marker="create_target">target system</seealso> created
by OTP tools. This since one easily can create a target system
where it is hard to even determine the base OTP version. You can,
however, place such a file there if you know the OTP version.</p>
</section>
<section>
<title>OTP Versions Table</title>
<p>The text file <c><OTP source root>/otp_versions.table</c>,
which is part of the source code, contains information about all
OTP versions from OTP 17.0 up to the current OTP version. Each line
contains information about application versions that are part of a
specific OTP version, and has the following format:</p>
<pre>
<OtpVersion> : <ChangedAppVersions> # <UnchangedAppVersions> :</pre>
<p><c><OtpVersion></c> has the format <c>OTP-<VSN></c>,
that is, the same as the git tag used to identify the source.</p>
<p><c><ChangedAppVersions></c> and
<c><UnchangedAppVersions></c> are space-separated lists of
application versions and has the format
<c><application>-<vsn></c>.</p>
<list type="bulleted">
<item><c><ChangedAppVersions></c> corresponds to changed
applications with new version numbers in this OTP version.</item>
<item><c><UnchangedAppVersions></c> corresponds to unchanged
application versions in this OTP version.</item>
</list>
<p>Both of them can be empty, but not at the same time.
If <c><ChangedAppVersions></c> is empty, no changes have
been made that change the build result of any application. This could,
for example, be a pure bug fix of the build system. The order of lines
is undefined. All white-space characters in this file are either space
(character 32) or line-break (character 10).</p>
<p>By using ordinary UNIX tools like <c>sed</c> and <c>grep</c> one
can easily find answers to various questions like:</p>
<list type="bulleted">
<item><p>Which OTP versions are <c>kernel-3.0</c> part of?</p>
<p><c>$ grep ' kernel-3\.0 ' otp_versions.table</c> </p></item>
<item><p>In which OTP version was <c>kernel-3.0</c> introduced?</p>
<p><c>$ sed 's/#.*//;/ kernel-3\.0 /!d' otp_versions.table</c>
</p></item>
</list>
<p>The above commands give a bit more information than the exact
answers, but adequate information when manually searching for answers
to these questions.</p>
<warning><p>The format of the <c>otp_versions.table</c> might be
subject to changes during the OTP 17 release.</p></warning>
</section>
</section>
<section>
<title>Application Version</title>
<p>As of OTP 17.0 application versions use the same
<seealso marker="#version_scheme">version scheme</seealso> as the
OTP version. Application versions part of a release candidate will
however not have an <c>-rc<N></c> suffix as the OTP version.
Also note that a major increment in an application version does not
necessarily imply a major increment of the OTP version. This depends
on whether the major change in the application is considered as a
major change for OTP as a whole or not.</p>
</section>
<section>
<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
application versions used in OTP 17.0</seealso> is included at the
end of this section</p></note>
<p>In the normal case, a version is constructed as
<c><Major>.<Minor>.<Patch></c>,
where <c><Major></c> is the most significant part.</p>
<p>However, more dot-separated parts than this can exist.
The dot-separated parts consist of non-negative integers. If
all parts less significant than <c><Minor></c> equals
<c>0</c>, they are omitted. The three normal parts
<c><Major>.<Minor>.<Patch></c> are changed as
follows:</p>
<list type="bulleted">
<item><c><Major></c> - Increases when major changes,
including incompatibilities, are made.</item>
<item><c><Minor></c> - Increases when new
functionality is added.</item>
<item><c><Patch></c> - Increases when pure bug fixes
are made.</item>
</list>
<p>When a part in the version number increases, all less significant
parts are set to <c>0</c>.</p>
<p>An application version or an OTP version identifies source code
versions. That is, it implies nothing about how the application
or OTP has been built.</p>
<section>
<title>Order of Versions</title>
<p>Version numbers in general are only partially ordered. However,
normal version numbers (with three parts) as of OTP 17.0 have a total
or linear order. This applies both to normal OTP versions and
normal application versions.</p>
<p>When comparing two version numbers that have an order, one
compare each part as ordinary integers from the most
significant part to less significant parts. The order is
defined by the first parts of the same significance that
differ. An OTP version with a larger version includes all
changes that are part of a smaller OTP version. The same
goes for application versions.</p>
<p>In general, versions can have more than three parts.
The versions are then only partially ordered. Such
versions are only used in exceptional cases. When an extra
part (out of the normal three parts) is added to a version number,
a new branch of versions is made. The new branch has a linear
order against the base version. However, versions on different
branches have no order, and therefore one can only conclude
that they all include what is included in their
closest common ancestor. When branching multiple times from the
same base version, <c>0</c> parts are added between the base
version and the least significant <c>1</c> part until a unique
version is found. Versions that have an order can be compared
as described in the previous paragraph.</p>
<p>An example of branched versions: The version <c>6.0.2.1</c>
is a branched version from the base version <c>6.0.2</c>.
Versions on the form <c>6.0.2.<X></c> can be compared
with normal versions smaller than or equal to <c>6.0.2</c>,
and other versions on the form <c>6.0.2.<X></c>. The
version <c>6.0.2.1</c> will include all changes in
<c>6.0.2</c>. However, <c>6.0.3</c> will most likely
<em>not</em> include all changes in <c>6.0.2.1</c> (note that
these versions have no order). A second branched version from the base
version <c>6.0.2</c> will be version <c>6.0.2.0.1</c>, and a
third branched version will be <c>6.0.2.0.0.1</c>.</p>
</section>
</section>
<section>
<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><Major>.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><Minor></c> version while
the release of an emergency patch package usually imply an
increase of the OTP <c><Patch></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
as smaller than the corresponding application version in the list,
the version number does not adhere to the version scheme introduced
in OTP 17.0 and is to be considered as not having an order against
versions used as of OTP 17.0.</p>
<list>
<item><c>asn1-3.0</c></item>
<item><c>common_test-1.8</c></item>
<item><c>compiler-5.0</c></item>
<item><c>cosEvent-2.1.15</c></item>
<item><c>cosEventDomain-1.1.14</c></item>
<item><c>cosFileTransfer-1.1.16</c></item>
<item><c>cosNotification-1.1.21</c></item>
<item><c>cosProperty-1.1.17</c></item>
<item><c>cosTime-1.1.14</c></item>
<item><c>cosTransactions-1.2.14</c></item>
<item><c>crypto-3.3</c></item>
<item><c>debugger-4.0</c></item>
<item><c>dialyzer-2.7</c></item>
<item><c>diameter-1.6</c></item>
<item><c>edoc-0.7.13</c></item>
<item><c>eldap-1.0.3</c></item>
<item><c>erl_docgen-0.3.5</c></item>
<item><c>erl_interface-3.7.16</c></item>
<item><c>erts-6.0</c></item>
<item><c>et-1.5</c></item>
<item><c>eunit-2.2.7</c></item>
<item><c>gs-1.5.16</c></item>
<item><c>hipe-3.10.3</c></item>
<item><c>ic-4.3.5</c></item>
<item><c>inets-5.10</c></item>
<item><c>jinterface-1.5.9</c></item>
<item><c>kernel-3.0</c></item>
<item><c>megaco-3.17.1</c></item>
<item><c>mnesia-4.12</c></item>
<item><c>observer-2.0</c></item>
<item><c>odbc-2.10.20</c></item>
<item><c>orber-3.6.27</c></item>
<item><c>os_mon-2.2.15</c></item>
<item><c>ose-1.0</c></item>
<item><c>otp_mibs-1.0.9</c></item>
<item><c>parsetools-2.0.11</c></item>
<item><c>percept-0.8.9</c></item>
<item><c>public_key-0.22</c></item>
<item><c>reltool-0.6.5</c></item>
<item><c>runtime_tools-1.8.14</c></item>
<item><c>sasl-2.4</c></item>
<item><c>snmp-4.25.1</c></item>
<item><c>ssh-3.0.1</c></item>
<item><c>ssl-5.3.4</c></item>
<item><c>stdlib-2.0</c></item>
<item><c>syntax_tools-1.6.14</c></item>
<item><c>test_server-3.7</c></item>
<item><c>tools-2.6.14</c></item>
<item><c>typer-0.9.6</c></item>
<item><c>webtool-0.8.10</c></item>
<item><c>wx-1.2</c></item>
<item><c>xmerl-1.3.7</c></item>
</list>
</section>
</chapter>