aboutsummaryrefslogtreecommitdiffstats
path: root/system/doc/system_principles
diff options
context:
space:
mode:
Diffstat (limited to 'system/doc/system_principles')
-rw-r--r--system/doc/system_principles/create_target.xmlsrc252
-rw-r--r--system/doc/system_principles/part.xml5
-rw-r--r--system/doc/system_principles/system_principles.xml11
-rw-r--r--system/doc/system_principles/upgrade.xml118
-rw-r--r--system/doc/system_principles/versions.xml267
-rw-r--r--system/doc/system_principles/xmlfiles.mk6
6 files changed, 622 insertions, 37 deletions
diff --git a/system/doc/system_principles/create_target.xmlsrc b/system/doc/system_principles/create_target.xmlsrc
index fbc935d708..a8ee2d1245 100644
--- a/system/doc/system_principles/create_target.xmlsrc
+++ b/system/doc/system_principles/create_target.xmlsrc
@@ -4,7 +4,7 @@
<chapter>
<header>
<copyright>
- <year>2002</year><year>2013</year>
+ <year>2002</year><year>2014</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
@@ -21,7 +21,7 @@
</legalnotice>
- <title>Creating a First Target System</title>
+ <title>Creating and Upgrading a Target System</title>
<prepared>Peter H&ouml;gfeldt</prepared>
<responsible></responsible>
<docno></docno>
@@ -71,26 +71,27 @@
</section>
<section>
+ <marker id="create"/>
<title>Creating a Target System</title>
<p>It is assumed that you have a working Erlang/OTP system structured
according to the OTP Design Principles.</p>
- <p><em>Step 1.</em> First create a <c>.rel</c> file (see
- <c>rel(4)</c>) that specifies the <c>erts</c> version
- and lists all applications that should be included in the new
- basic target system. An example is the following
+ <p><em>Step 1.</em> First create a <c>.rel</c> file (see <seealso
+ marker="sasl:rel">rel(4)</seealso>) that specifies the <c>erts</c>
+ version and lists all applications that should be included in the
+ new basic target system. An example is the following
<c>mysystem.rel</c> file:</p>
<code type="none">
%% mysystem.rel
{release,
{"MYSYSTEM", "FIRST"},
- {erts, "5.1"},
- [{kernel, "2.7"},
- {stdlib, "1.10"},
- {sasl, "1.9.3"},
- {pea, "1.0"}]}. </code>
+ {erts, "5.10.4"},
+ [{kernel, "2.16.4"},
+ {stdlib, "1.19.4"},
+ {sasl, "2.3.4"},
+ {pea, "1.0"}]}.</code>
<p>The listed applications are not only original Erlang/OTP
applications but possibly also new applications that you have
- written yourself (here examplified by the application
+ written yourself (here exemplified by the application
<c>pea</c>). </p>
<p><em>Step 2.</em> From the directory where the <c>mysystem.rel</c>
file reside, start the Erlang/OTP system:</p>
@@ -116,13 +117,13 @@ os> <input>erl -pa /home/user/target_system/myapps/pea-1.0/ebin</input></pre>
<c>systools:make_tar/2</c>. That file has the following
contents:</p>
<code type="none">
-erts-5.1/bin/
+erts-5.10.4/bin/
releases/FIRST/start.boot
releases/FIRST/mysystem.rel
releases/mysystem.rel
-lib/kernel-2.7/
-lib/stdlib-1.10/
-lib/sasl-1.9.3/
+lib/kernel-2.16.4/
+lib/stdlib-1.19.4/
+lib/sasl-2.3.4/
lib/pea-1.0/ </code>
<p>The file <c>releases/FIRST/start.boot</c> is a copy of our
<c>mysystem.boot</c></p>
@@ -142,16 +143,19 @@ lib/pea-1.0/ </code>
<item>Creates the temporary directory <c>tmp</c> and extracts the tar file
<c>mysystem.tar.gz</c> into that directory. </item>
<item>Deletes the <c>erl</c> and <c>start</c> files from
- <c>tmp/erts-5.1/bin</c>. These files will be created again from
+ <c>tmp/erts-5.10.4/bin</c>. These files will be created again from
source when installing the release.</item>
<item>Creates the directory <c>tmp/bin</c>.</item>
<item>Copies the previously created file <c>plain.boot</c> to
<c>tmp/bin/start.boot</c>.</item>
<item>Copies the files <c>epmd</c>, <c>run_erl</c>, and
- <c>to_erl</c> from the directory <c>tmp/erts-5.1/bin</c> to
+ <c>to_erl</c> from the directory <c>tmp/erts-5.10.4/bin</c> to
the directory <c>tmp/bin</c>.</item>
+ <item>Creates the directory <c>tmp/log</c>, which will be used
+ if the system is started as embedded with the <c>bin/start</c>
+ script.</item>
<item>Creates the file <c>tmp/releases/start_erl.data</c> with
- the contents "5.1 FIRST". This file is to be passed as data
+ the contents "5.10.4 FIRST". This file is to be passed as data
file to the <c>start_erl</c> script.
</item>
<item>Recreates the file <c>mysystem.tar.gz</c> from the directories
@@ -171,11 +175,11 @@ lib/pea-1.0/ </code>
<item>Extracts the tar file <c>mysystem.tar.gz</c> into the target
directory <c>/usr/local/erl-target</c>.</item>
<item>In the target directory reads the file <c>releases/start_erl.data</c>
- in order to find the Erlang runtime system version ("5.1").</item>
+ in order to find the Erlang runtime system version ("5.10.4").</item>
<item>Substitutes <c>%FINAL_ROOTDIR%</c> and <c>%EMU%</c> for
<c>/usr/local/erl-target</c> and <c>beam</c>, respectively, in
the files <c>erl.src</c>, <c>start.src</c>, and
- <c>start_erl.src</c> of the target <c>erts-5.1/bin</c>
+ <c>start_erl.src</c> of the target <c>erts-5.10.4/bin</c>
directory, and puts the resulting files <c>erl</c>,
<c>start</c>, and <c>run_erl</c> in the target <c>bin</c>
directory.</item>
@@ -185,6 +189,7 @@ lib/pea-1.0/ </code>
</section>
<section>
+ <marker id="start"/>
<title>Starting a Target System</title>
<p>Now we have a target system that can be started in various ways.</p>
<p>We start it as a <em>basic target system</em> by invoking</p>
@@ -193,7 +198,7 @@ os> <input>/usr/local/erl-target/bin/erl</input></pre>
<p>where only the <c>kernel</c> and <c>stdlib</c> applications are
started, i.e. the system is started as an ordinary development
system. There are only two files needed for all this to work:
- <c>bin/erl</c> file (obtained from <c>erts-5.1/bin/erl.src</c>)
+ <c>bin/erl</c> file (obtained from <c>erts-5.10.4/bin/erl.src</c>)
and the <c>bin/start.boot</c> file (a copy of <c>plain.boot</c>).</p>
<p>We can also start a distributed system (requires <c>bin/epmd</c>).</p>
<p>To start all applications specified in the original
@@ -208,9 +213,10 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
<c>bin/run_erl</c>, which in turn calls <c>bin/start_erl</c>
(roughly, <c>start_erl</c> is an embedded variant of
<c>erl</c>). </p>
- <p>The shell script <c>start</c> is only an example. You should
- edit it to suite your needs. Typically it is executed when the
- UNIX system boots.</p>
+ <p>The shell script <c>start</c>, which is generated from
+ erts-5.10.4/bin/start.src during installation, is only an
+ example. You should edit it to suite your needs. Typically it is
+ executed when the UNIX system boots.</p>
<p><c>run_erl</c> is a wrapper that provides logging of output from
the run-time system to file. It also provides a simple mechanism
for attaching to the Erlang shell (<c>to_erl</c>).</p>
@@ -218,7 +224,7 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
(<c>"/usr/local/erl-target"</c>), the releases directory
(<c>"/usr/local/erl-target/releases"</c>), and the location of
the <c>start_erl.data</c> file. It reads the run-time system
- version (<c>"5.1"</c>) and release version (<c>"FIRST"</c>) from
+ version (<c>"5.10.4"</c>) and release version (<c>"FIRST"</c>) from
the <c>start_erl.data</c> file, starts the run-time system of the
version found, and provides <c>-boot</c> flag specifying the boot
file of the release version found
@@ -245,7 +251,7 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
<c>target_system:create/1</c>. In fact, if you create, in the
current directory, not only the <c>mysystem.rel</c> file, but
also a <c>sys.config</c> file, that latter file will be tacitly
- put in the apropriate directory.</p>
+ put in the appropriate directory.</p>
</section>
<section>
@@ -258,6 +264,198 @@ os> <input>/usr/local/erl-target/bin/erl -boot /usr/local/erl-target/releases/FI
</section>
<section>
+ <title>Creating the Next Version</title>
+
+ <p>
+ In this example the <c>pea</c> application has been changed, and
+ so are <c>erts</c>, <c>kernel</c>, <c>stdlib</c> and
+ <c>sasl</c>.
+ </p>
+
+ <p>
+ <em>Step 1.</em> Create the <c>.rel</c> file:
+ </p>
+ <code type="none">
+%% mysystem2.rel
+{release,
+ {"MYSYSTEM", "SECOND"},
+ {erts, "6.0"},
+ [{kernel, "3.0"},
+ {stdlib, "2.0"},
+ {sasl, "2.4"},
+ {pea, "2.0"}]}.</code>
+ <p>
+ <em>Step 2.</em> Create the application upgrade file (see
+ <seealso marker="sasl:appup">appup(4)</seealso>) for <c>pea</c>,
+ for example:
+ </p>
+ <code type="none">
+%% pea.appup
+{"2.0",
+ [{"1.0",[{load_module,pea_lib}]}],
+ [{"1.0",[{load_module,pea_lib}]}]}.</code>
+ <p>
+ <em>Step 3.</em> From the directory where the
+ <c>mysystem2.rel</c> file reside, start the Erlang/OTP system:
+ </p>
+ <pre>
+os> <input>erl -pa /home/user/target_system/myapps/pea-2.0/ebin</input></pre>
+ <p>giving the path to the new version of <c>pea</c>. </p>
+
+ <p>
+ <em>Step 4.</em> Create the release upgrade file (see <seealso
+ marker="sasl:relup">relup(4)</seealso>):
+ </p>
+ <pre>
+1> <input>systools:make_relup("mysystem2",["mysystem"],["mysystem"],[{path,["/home/user/target_system/myapps/pea-1.0/ebin","/my/old/erlang/lib/*/ebin"]}]).</input></pre>
+ <p>
+ where <c>"mysystem"</c> is the base release and
+ <c>"mysystem2"</c> is the release to upgrade to.
+ </p>
+ <p>
+ Note that the <c>path</c> option is used for pointing out the
+ old version of all applications. (The new versions are already
+ in the code path - assuming of course that the erlang node on
+ which this is executed is running the correct version of
+ Erlang/OTP.)
+ </p>
+ <p>
+ <em>Step 5.</em> Create the new release:
+ </p>
+ <pre>
+2> <input>target_system:create("mysystem2").</input></pre>
+ <p>
+ Given that the <c>relup</c> file generated in step 4 above is
+ now located in the current directory, it will automatically be
+ included in the release package.
+ </p>
+ </section>
+
+ <section>
+ <title>Upgrading the Target System</title>
+ <p>
+ This part is done on the target node, and for this example we
+ want the node to be running as an embedded system with the
+ <c>-heart</c> option, allowing automatic restart of the
+ node. See <seealso marker="#start">Starting a Target
+ System</seealso> above for more information.
+ </p>
+ <p>
+ We add <c>-heart</c> to <c>bin/start</c>:
+ </p>
+ <code type="none">
+#!/bin/sh
+ROOTDIR=/usr/local/erl-target/
+
+if [ -z "$RELDIR" ]
+then
+ RELDIR=$ROOTDIR/releases
+fi
+
+START_ERL_DATA=${1:-$RELDIR/start_erl.data}
+
+$ROOTDIR/bin/run_erl -daemon /tmp/ $ROOTDIR/log "exec $ROOTDIR/bin/start_erl $ROOTDIR $RELDIR $START_ERL_DATA -heart</code>
+ <p>
+ And we use the simplest possible <c>sys.config</c>, which we
+ store in <c>releases/FIRST</c>:
+ </p>
+ <code type="none">
+%% sys.config
+[].</code>
+ <p>
+ Finally, in order to prepare the upgrade, we need to put the new
+ release package in the <c>releases</c> directory of the first
+ target system:
+ </p>
+ <pre>
+os> <input>cp mysystem2.tar.gz /usr/local/erl-target/releases</input></pre>
+ <p>
+ And assuming that the node has been started like this:
+ </p>
+ <pre>
+os> <input>/usr/local/erl-target/bin/start</input></pre>
+ <p>
+ it can be accessed like this:
+ </p>
+ <pre>
+os> <input>/usr/local/erl-target/bin/to_erl /tmp/erlang.pipe.1</input></pre>
+ <p>
+ Also note that logs can be found in
+ <c>/usr/local/erl-target/log</c>. This directory is specified as
+ an argument to <c>run_erl</c>in the start script listed above.
+ </p>
+ <p>
+ <em>Step 1.</em> Unpack the release:
+ </p>
+ <pre>
+1> <input>{ok,Vsn} = release_handler:unpack_release("mysystem2").</input></pre>
+ <p>
+ <em>Step 2.</em> Install the release:
+ </p>
+ <pre>
+2> <input>release_handler:install_release(Vsn).</input>
+<output>{continue_after_restart,"FIRST",[]}
+heart: Tue Apr 1 12:15:10 2014: Erlang has closed.
+heart: Tue Apr 1 12:15:11 2014: Executed "/usr/local/erl-target/bin/start /usr/local/erl-target/releases/new_start_erl.data" -> 0. Terminating.
+[End]</output></pre>
+ <p>
+ The above return value and output after the call to
+ <c>release_handler:install_release/1</c> means that the
+ <c>release_handler</c> has restarted the node by using
+ <c>heart</c>. This will always be done when the upgrade involves
+ a change of <c>erts</c>, <c>kernel</c>, <c>stdlib</c> or
+ <c>sasl</c>. See <seealso marker="upgrade">Upgrade when
+ Erlang/OTP has Changed</seealso> for more infomation about this.
+ </p>
+ <p>
+ The node will be accessible via a new pipe:
+ </p>
+ <pre>
+os> <input>/usr/local/erl-target/bin/to_erl /tmp/erlang.pipe.2</input></pre>
+ <p>
+ Let's see which releases we have in our system:
+ </p>
+ <pre>
+1> <input>release_handler:which_releases().</input>
+<output>[{"MYSYSTEM","SECOND",
+ ["kernel-3.0","stdlib-2.0","sasl-2.4","pea-2.0"],
+ current},
+ {"MYSYSTEM","FIRST",
+ ["kernel-2.16.4","stdlib-1.19.4","sasl-2.3.4","pea-1.0"],
+ permanent}]</output></pre>
+ <p>
+ Our new release, "SECOND", is now the current release, but we
+ can also see that our "FIRST" release is still permanent. This
+ means that if the node would be restarted at this point, it
+ would come up running the "FIRST" release again.
+ </p>
+ <p>
+ <em>Step 3.</em> Make the new release permanent:
+ </p>
+ <pre>
+2> <input>release_handler:make_permanent("SECOND").</input></pre>
+
+ <p>
+ Now look at the releases again:
+ </p>
+
+ <pre>
+3> <input>release_handler:which_releases().</input>
+<output>[{"MYSYSTEM","SECOND",
+ ["kernel-3.0","stdlib-2.0","sasl-2.4","pea-2.0"],
+ permanent},
+ {"MYSYSTEM","FIRST",
+ ["kernel-2.16.4","stdlib-1.19.4","sasl-2.3.4","pea-1.0"],
+ old}]</output></pre>
+
+ <p>
+ Here we see that the new release version is <c>permanent</c>, so
+ it would be safe to restart the node.
+ </p>
+
+ </section>
+
+ <section>
<title>Listing of target_system.erl</title>
<p>This module can also be found in the <c>examples</c> directory
of the <c>sasl</c> application.</p>
diff --git a/system/doc/system_principles/part.xml b/system/doc/system_principles/part.xml
index 915d5aca9b..d05c89fde8 100644
--- a/system/doc/system_principles/part.xml
+++ b/system/doc/system_principles/part.xml
@@ -4,7 +4,7 @@
<part xmlns:xi="http://www.w3.org/2001/XInclude">
<header>
<copyright>
- <year>1997</year><year>2013</year>
+ <year>1997</year><year>2014</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
@@ -31,5 +31,6 @@
<xi:include href="system_principles.xml"/>
<xi:include href="error_logging.xml"/>
<xi:include href="create_target.xml"/>
+ <xi:include href="upgrade.xml"/>
+ <xi:include href="versions.xml"/>
</part>
-
diff --git a/system/doc/system_principles/system_principles.xml b/system/doc/system_principles/system_principles.xml
index 4f2202fdd1..79ed86cd9f 100644
--- a/system/doc/system_principles/system_principles.xml
+++ b/system/doc/system_principles/system_principles.xml
@@ -4,7 +4,7 @@
<chapter>
<header>
<copyright>
- <year>1996</year><year>2013</year>
+ <year>1996</year><year>2014</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
@@ -34,13 +34,12 @@
<p>An Erlang runtime system is started with the command <c>erl</c>:</p>
<pre>
% <input>erl</input>
-Erlang (BEAM) emulator version 5.2.3.5 [hipe] [threads:0]
+Erlang/OTP 17 [erts-6.0] [hipe] [smp:8:8]
-Eshell V5.2.3.5 (abort with ^G)
+Eshell V6.0 (abort with ^G)
1> </pre>
<p><c>erl</c> understands a number of command line arguments, see
- <c>erl(1)</c>. A number of them are also described in this
- chapter.</p>
+ <c>erl(1)</c>. A number of them are also described in this chapter.</p>
<p>Application programs can access the values of the command line
arguments by calling one of the functions
<c>init:get_argument(Key)</c>, or <c>init:get_arguments()</c>.
@@ -110,7 +109,7 @@ init:stop()</pre>
<p>Loads the code for and starts the applications Kernel and
STDLIB, skips loading the <c>.erlang</c> file.
Useful for scripts and other tools that should be behave the
- same irregardless of user preferences.
+ same regardless of user preferences.
</p>
</item>
</taglist>
diff --git a/system/doc/system_principles/upgrade.xml b/system/doc/system_principles/upgrade.xml
new file mode 100644
index 0000000000..68e48da0b8
--- /dev/null
+++ b/system/doc/system_principles/upgrade.xml
@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+ <header>
+ <copyright>
+ <year>2014</year>
+ <holder>Ericsson AB. All Rights Reserved.</holder>
+ </copyright>
+ <legalnotice>
+ The contents of this file are subject to the Erlang Public License,
+ Version 1.1, (the "License"); you may not use this file except in
+ compliance with the License. You should have received a copy of the
+ Erlang Public License along with this software. If not, it can be
+ retrieved online at http://www.erlang.org/.
+
+ Software distributed under the License is distributed on an "AS IS"
+ basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ the License for the specific language governing rights and limitations
+ under the License.
+
+ </legalnotice>
+
+ <title>Upgrade when Erlang/OTP has Changed</title>
+ <prepared></prepared>
+ <responsible></responsible>
+ <docno></docno>
+ <approved></approved>
+ <checked></checked>
+ <date>2014-02-19</date>
+ <rev></rev>
+ <file>upgrade.xml</file>
+ </header>
+
+ <section>
+ <title>Introduction</title>
+ <p>
+ As of Erlang/OTP 17, most applications deliver a valid
+ application upgrade (<c>appup</c>) file. In earlier releases, a
+ majority of the applications in Erlang/OTP did not support
+ upgrade at all. Many of the applications use the
+ <c>restart_application</c> instruction. These are applications
+ for which it is not crucial to support real soft upgrade, for
+ instance tools and library applications. The
+ <c>restart_application</c> instruction
+ ensures that all modules in the application are reloaded and
+ thereby running the new code.
+ </p>
+ </section>
+
+ <section>
+ <title>Upgrade of core applications</title>
+ <p>
+ The core applications ERTS, Kernel, STDLIB
+ and SASL never allow real soft upgrade, but require the
+ Erlang emulator to be restarted. This is indicated to the
+ <c>release_handler</c> by the upgrade instruction
+ <c>restart_new_emulator</c>. This instruction will always be the
+ very first instruction executed, and it will restart the
+ emulator with the new versions of the above mentioned core
+ applications and the old versions of all other
+ applications. When the node is back up all other upgrade instructions are
+ executed, making sure each application is finally running its
+ new version.
+ </p>
+
+ <p>
+ It might seem strange to do a two-step upgrade instead of
+ just restarting the emulator with the new version of all
+ applications. The reason for this design decision is to allow
+ <c>code_change</c> functions to have side effects, for example changing
+ data on disk. It also makes sure that the upgrade mechanism for
+ non-core applications does not differ depending on whether or not
+ core applications are changed at the same time.
+ </p>
+
+ <p>
+ If, however, the more brutal variant is preferred, it is
+ possible to handwrite the release upgrade file using only the
+ single upgrade instruction <c>restart_emulator</c>. This
+ instruction, in contrast to <c>restart_new_emulator</c>, will
+ cause the emulator to restart with the new versions of
+ <em>all</em> applications.
+ </p>
+
+ <p>
+ <em>Note</em> that if other instructions are included before
+ <c>restart_emulator</c> in the handwritten <c>relup</c> file,
+ they will be executed in the old emulator. This is a big risk
+ since there is no guarantee that new beam code can be loaded
+ into the old emulator. Adding instructions after
+ <c>restart_emulator</c> has no effect as the
+ <c>release_handler</c> will not do any attempt at executing
+ them.
+ </p>
+
+ <p>
+ See <seealso marker="sasl:relup">relup(4)</seealso> for
+ information about the release upgrade file, and <seealso
+ marker="sasl:appup">appup(4)</seealso> for further information
+ about upgrade instructions.
+ </p>
+ </section>
+
+ <section>
+ <title>Applications that still do not allow code upgrade</title>
+ <p>
+ A few applications, for instance HiPE do not support
+ upgrade at all. This is indicated by an application upgrade file
+ containing only <c>{Vsn,[],[]}</c>. Any attempt at creating a release
+ upgrade file with such input will fail.
+ The only way to force an upgrade involving applications like this is to
+ handwrite the <c>relup</c> file, preferably as described above
+ with only the <c>restart_emulator</c> instruction.
+ </p>
+
+ </section>
+</chapter>
diff --git a/system/doc/system_principles/versions.xml b/system/doc/system_principles/versions.xml
new file mode 100644
index 0000000000..ff042f4a3b
--- /dev/null
+++ b/system/doc/system_principles/versions.xml
@@ -0,0 +1,267 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+ <header>
+ <copyright>
+ <year>2014</year>
+ <holder>Ericsson AB. All Rights Reserved.</holder>
+ </copyright>
+ <legalnotice>
+ The contents of this file are subject to the Erlang Public License,
+ Version 1.1, (the "License"); you may not use this file except in
+ compliance with the License. You should have received a copy of the
+ Erlang Public License along with this software. If not, it can be
+ retrieved online at http://www.erlang.org/.
+
+ Software distributed under the License is distributed on an "AS IS"
+ basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ the License for the specific language governing rights 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><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 <seealso marker="#version_scheme">version
+ scheme</seealso> used is described in more detail below.</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&lt;N&gt;</c>
+ suffix. The suffix <c>-rc0</c> will be 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>&lt;OTP source root&gt;/OTP_VERSION</c>. The
+ absolute path to the file can be constructed by calling
+ <c>filename:join([<seealso marker="kernel:code#root_dir/0">code:root_dir()</seealso>, "OTP_VERSION"])</c>.</p>
+ <p>In an installed OTP development system, the OTP version can be read
+ from the text file <c>&lt;OTP installation root&gt;/releases/&lt;OTP release number&gt;/OTP_VERSION</c>.
+ The absolute path to the file can by constructed by calling
+ <c>filename:join([<seealso marker="kernel:code#root_dir/0">code:root_dir()</seealso>, "releases", <seealso marker="erts:erlang#system_info_otp_release">erlang:system_info(otp_release)</seealso>, "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 <c>otp_patch_apply</c> tool available to
+ licensed customers. 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. Note that if a development system is updated by
+ other means than <c>otp_patch_apply</c>, the <c>OTP_VERSION</c> file
+ may identify an incorrect OTP version.</p>
+
+ <p>No <c>OTP_VERSION</c> file will be 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 may,
+ however, place such a file there yourself if you know the OTP
+ version.</p>
+ </section>
+
+ <section><title>OTP Versions Table</title>
+ <p>The text file <c>&lt;OTP source root&gt;/otp_versions.table</c> that
+ is part of the source code contains information about all OTP versions
+ from OTP 17.0 up to current OTP version. Each line contains information
+ about application versions that are part of a specific OTP version, and
+ is on the format:</p>
+<pre>
+&lt;OtpVersion&gt; : &lt;ChangedAppVersions&gt; # &lt;UnchangedAppVersions&gt; :
+</pre>
+ <p><c>&lt;OtpVersion&gt;</c> is on the format <c>OTP-&lt;VSN&gt;</c>, i.e.,
+ the same as the git tag used to identify the source.
+ <c>&lt;ChangedAppVersions&gt;</c> and <c>&lt;UnchangedAppVersions&gt;</c>
+ are space separated lists of application versions on the
+ format <c>&lt;application&gt;-&lt;vsn&gt;</c>.
+ <c>&lt;ChangedAppVersions&gt;</c> corresponds to changed applications
+ with new version numbers in this OTP version, and
+ <c>&lt;UnchangedAppVersions&gt;</c> corresponds to unchanged application
+ versions in this OTP version. Both of them might be empty, although
+ not at the same time. If &lt;ChangedAppVersions&gt; is empty, no changes
+ has 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>Using ordinary UNIX tools like <c>sed</c> and <c>grep</c> one
+ can easily find answers to various questions like:</p>
+ <taglist>
+ <tag>Which OTP versions are <c>kernel-3.0</c> part of?</tag>
+ <item><p><c> $ grep ' kernel-3\.0 ' otp_versions.table</c></p></item>
+ <tag>In which OTP version was <c>kernel-3.0</c> introduced?</tag>
+ <item><p><c> $ sed 's/#.*//;/ kernel-3\.0 /!d' otp_versions.table</c></p></item>
+ </taglist>
+ <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 will 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&lt;N&gt;</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>
+
+ <marker id="version_scheme"/>
+ <section><title>Version Scheme</title>
+ <note>Note that 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> can be found
+ at the end of this document.</note>
+
+ <p>In the normal case, a version will be constructed as
+ <c>&lt;Major&gt;.&lt;Minor&gt;.&lt;Patch&gt;</c> where <c>&lt;Major&gt;</c>
+ is the most significant part. However, more dot separated parts than
+ this may exist. The dot separated parts consists of non-negative integers.
+ If all parts less significant than <c>&lt;Minor&gt;</c> equals <c>0</c>,
+ they are omitted. The three normal parts
+ <c>&lt;Major&gt;.&lt;Minor&gt;.&lt;Patch&gt;</c> will be changed as
+ follows:</p>
+ <taglist>
+ <tag><c>&lt;Major&gt;</c></tag><item>Increased when major changes,
+ including incompatibilities, have been made.</item>
+ <tag><c>&lt;Minor&gt;</c></tag><item>Increased when new functionality
+ has been added.</item>
+ <tag><c>&lt;Patch&gt;</c></tag><item>Increased when pure bug fixes
+ have been made.</item>
+ </taglist>
+ <p>When a part in the version number is increased, 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 does not imply anything 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 towards less significant parts. The order is
+ defined by the first parts of the same significance that
+ differ. An OTP version with a larger version include all
+ changes that that are part of a smaller OTP version. The same
+ goes for application versions.</p>
+
+ <p>In the general case, versions may have more than three parts. In
+ this case the versions are only partially ordered. Note that 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. Since they have no order, we
+ only know 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 paragraph above.</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.&lt;X&gt;</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.&lt;X&gt;</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>
+
+ <marker id="otp_17_0_app_versions"/>
+ <section><title>OTP 17.0 Application Versions</title>
+ <p>The following application versions were part of OTP 17.0. If
+ the normal part of an applications version number compares
+ as smaller than the corresponding application version in this list,
+ the version number does not adhere to the version scheme introduced
+ in OTP 17.0 and should 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>
+
diff --git a/system/doc/system_principles/xmlfiles.mk b/system/doc/system_principles/xmlfiles.mk
index 4cbc00ed52..c60ffbad28 100644
--- a/system/doc/system_principles/xmlfiles.mk
+++ b/system/doc/system_principles/xmlfiles.mk
@@ -1,7 +1,7 @@
#
# %CopyrightBegin%
#
-# Copyright Ericsson AB 2009. All Rights Reserved.
+# Copyright Ericsson AB 2009-2014. All Rights Reserved.
#
# The contents of this file are subject to the Erlang Public License,
# Version 1.1, (the "License"); you may not use this file except in
@@ -19,4 +19,6 @@
SYSTEM_PRINCIPLES_CHAPTER_FILES = \
system_principles.xml \
error_logging.xml \
- create_target.xml
+ create_target.xml \
+ upgrade.xml \
+ versions.xml