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<h1 style="text-align: center">Apache Subversion 1.9 Release Notes</h1>
<div class="h2" id="news">
<h2>What's New in Apache Subversion 1.9
<a class="sectionlink" href="#news"
title="Link to this section">¶</a>
</h2>
<ul>
<li><a href="#fsfs-improvements"
>FSFS improvements</a></li>
<li><a href="#fsx"
>FSX – A new experimental repository backend</a></li>
<li><a href="#enhancements"
>Many enhancements and bug fixes</a></li>
<li><a href="#issues"
>Known issues in the release</a></li>
<li><a href="#troubleshooting"
>Troubleshooting issues specific to this release</a></li>
</ul>
<p>Apache Subversion 1.9 is a superset of all previous Subversion
releases, and is as of the time of its release considered the current
"best" release. Any feature or bugfix in 1.0.x through 1.8.x is also
in 1.9, but 1.9 contains features and bugfixes not present in any
earlier release. The new features will eventually be documented in a
1.9 version of the free Subversion book
(<a href="http://svnbook.red-bean.com/" >svnbook.red-bean.com</a>).</p>
<p>This page describes only major changes. For a complete list of
changes, see the 1.9 section of the <a
href="https://svn.apache.org/repos/asf/subversion/trunk/CHANGES" >CHANGES</a>
file.</p>
</div> <!-- news -->
<div class="h2" id="compatibility">
<h2>Compatibility Concerns
<a class="sectionlink" href="#compatibility"
title="Link to this section">¶</a>
</h2>
<p>Older clients and servers interoperate transparently with 1.9
servers and clients. However, some of the new 1.9 features may not be
available unless both client and server are the latest version. There are
also cases where a new feature will work but will run less efficiently if
the client is new and the server old.</p>
<p>There is <strong>no need</strong> to <a href="http://svnbook.red-bean.com/en/1.7/svn.reposadmin.maint.html#svn.reposadmin.maint.migrate.svnadmin"
>dump and reload</a> your repositories.
Subversion 1.9 servers can read and write to repositories created by
earlier versions. To upgrade an existing server installation, just install the
newest libraries and binaries on top of the older ones.</p>
<p>Subversion 1.9 maintains API/ABI compatibility with earlier
releases, by only adding new functions, never removing old ones. A
program written to any previous 1.x API can both compile
and run using 1.9 libraries. However, a program written for 1.9
cannot necessarily compile or run against older libraries.</p>
<p>There may be limited cases where the behavior of old APIs has been
slightly modified from previous releases. These are cases where edge cases
of the functionality has been deemed buggy, and therefore improved or removed.
Please consult the
<a href="https://svn.apache.org/repos/asf/subversion/trunk/notes/api-errata/1.9/"
>API errata</a> for more detailed information on what these APIs are
and what impact these changes may have.</p>
<div class="h3" id="new-feature-compatibility-table">
<h3>New Feature Compatibility Table
<a class="sectionlink" href="#new-feature-compatibility-table"
title="Link to this section">¶</a>
</h3>
<table border="1">
<tr>
<th>New Feature</th>
<th>Minimum Client<sup>1</sup></th>
<th>Minimum Server</th>
<th>Minimum Repository</th>
<th>Notes</th></tr>
<tr>
<td><a href="#prospective-blame">Prospective blame</a></td>
<td>1.9</td>
<td>1.8</td>
<td>any</td>
<td></td></tr>
<tr>
<td><a href="#fsfs-improvements">FSFS format 7</a></td>
<td>any</td>
<td>1.9</td>
<td>1.9</td>
<td>Older formats remain supported.</td></tr>
<tr>
<td><a href="#lock-http-pipelining">Lock HTTP pipelining</a></td>
<td>1.9</td>
<td>1.2</td>
<td>1.2</td>
<td></td></tr>
<tr>
<td><a href="#locking-multiple-files">Commit unlocking</a></td>
<td>1.2</td>
<td>1.9</td>
<td>1.2</td>
<td></td></tr>
<tr>
<td><a href="#locking-multiple-files">Locking multiple files</a></td>
<td>1.3</td>
<td>1.9</td>
<td>1.2</td>
<td>Over the svn:// protocol.</td></tr>
<tr>
<td><a href="#fsx">FSX</a></td>
<td>any</td>
<td>1.9</td>
<td>1.9</td>
<td>Will not be compatible with 1.10</td></tr>
<tr>
<td colspan="5"><sup>1</sup>Reminder: when using the <tt>file://</tt>
repository access method, the Subversion program is both the client
<em>and</em> the server.</td></tr>
</table>
</div> <!-- new-feature-compatibility-table -->
<div class="h3" id="wc-upgrade">
<h3>Upgrading the Working Copy
<a class="sectionlink" href="#wc-upgrade"
title="Link to this section">¶</a>
</h3>
<p>Subversion 1.9 uses the same working copy format as Subversion 1.8.</p>
<p>Before using Subversion 1.9 with an existing Subversion 1.7 or older
working copy, users will be required to run the <tt>svn upgrade</tt> command
to upgrade working copy metadata to the new format. This command may take a
while in some cases, and for some users, it may be more practical to simply
checkout a new working copy.</p>
<p><strong>Note:</strong> Subversion 1.9 cannot upgrade working copies that
a 1.6 client would have refused to operate upon before an <tt>svn cleanup</tt>
was run (with a 1.6 client). In other words, before upgrading to 1.9, a 1.6
or older client must be used to run <tt>svn cleanup</tt> on all 1.6 or older
working copies that require cleanup. Likewise, Subversion 1.9 cannot upgrade
corrupt working copies. Unfixable problems can arise from missing or corrupt
meta-data inside <tt>.svn</tt> directories. Such damage to the working copy
is permanent, and cannot be fixed even if <tt>svn cleanup</tt> is run prior
to the upgrade.</p>
<p>If your working copy does not upgrade cleanly, please check out a new one.
</p>
</div> <!-- wc-upgrade -->
<div class="h3" id="compat-deps">
<h3>Upgraded Minimal Dependencies
<a class="sectionlink" href="#compat-deps"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="python-2.7">
<h4>Python (optional dependency) must be ≥2.7
<a class="sectionlink" href="#python-2.7"
title="Link to this section">¶</a>
</h4>
<p>The <a href="https://www.python.org/">Python</a> programming language is an
optional dependency. It is required for running the test suite and for
building nightly versions, but not for building from packaged releases.</p>
<p>Subversion 1.8 supported Python 2.5 and newer. Subversion 1.9 requires
Python 2.7. Older versions of Python are no longer guaranteed to work.</p>
<p>We break compatibility with Python 2.6 and older since it has been
end-of-life for nearly two years, and in order to introduce compatibility with
Python 3.x in patch releases of the 1.9.x line.</p>
</div> <!-- python-2.7 -->
</div> <!-- compat-deps -->
<div class="h3" id="compat-misc">
<h3>Miscellaneous Compatibility Notes
<a class="sectionlink" href="#compat-misc"
title="Link to this section">¶</a>
</h3>
<p>There are some additional specific areas where changes made in this
release might necessitate further adjustment by administrators or
users. We'll cover those in this section.</p>
<div class="h4" id="next-release-is-1.10">
<h4>Next release will be numbered 1.10
<a class="sectionlink" href="#next-release-is-1.10"
title="Link to this section">¶</a>
</h4>
<p>The next minor release after 1.9.0 will be numbered 1.10.0.</p>
<p>Since "1.10.0" is smaller than "1.9.0" when considered as ASCII strings,
scripts that compare Subversion versions as strings may fail to correctly
determine which of "1.10.0" and "1.9.0" is the more recent one. Such
scripts should be changed to compare Subversion version numbers correctly:
as tuples of integers, with an optional suffix for development or pre-release
versions. See
<a href="/docs/community-guide/releasing#release-numbering"
>the Subversion release numbering documentation</a>
for details. (Programs written against the C API or the various bindings
should refer to the
<!-- TODO: link is broken (doxygen not yet generated) -->
<a href="https://subversion.apache.org/docs/api/1.9/svn__version_8h.html"
><tt>svn_version_*</tt> interfaces</a>.)</p>
<p>The next patch releases on the 1.9.x line will be numbered 1.9.1, 1.9.2,
…, as usual.</p>
</div> <!-- next-release-is-1.10 -->
</div> <!-- compat-misc -->
</div> <!-- compatibility -->
<div class="h2" id="new-features">
<h2>New Features
<a class="sectionlink" href="#new-features"
title="Link to this section">¶</a>
</h2>
<div class="h3" id="fsfs-improvements">
<h3>FSFS improvements
<a class="sectionlink" href="#fsfs-improvements"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="fsfs-format7">
<h4>Format bump
<a class="sectionlink" href="#fsfs-format7"
title="Link to this section">¶</a>
</h4>
<p>The default filesystem format is now a new format, numbered 7.
(The new command <a href="#svnadmin-info" title="svnadmin info">
<tt>svnadmin info</tt></a> displays the filesystem format number
of a repository.)
In contrast to previous
releases, format 7 is a major overhaul with the general goal of I/O reduction.
Major changes include:
</p>
<ul>
<li>Revision content is no longer addressed by physical location (offset)
within the rev file but by logical item numbers. Two indexes provide
the necessary mapping information. You can no longer manipulate the
rev / pack file contents manually.</li>
<li><tt>svnadmin pack</tt> reorders the revision data such that related
information is put next to each other and can often be read with a
single I/O.</li>
<li>Block reads are an option now and will fetch data in larger blocks of
configurable size (64kB by default) and cache all of their contents.
This eliminates much of the OS overhead.</li>
<li>Explicit flags for <tt>svn:mergeinfo</tt> changes speed up
mergeinfo-related operations like <tt>svn log -g</tt>.</li>
<li>Full checksum coverage of all revision data, including meta data and
structural information.</li>
<li>Allow commits while packing is in progress.</li>
</ul>
<p>As with earlier releases, you may simply run <tt>svnadmin upgrade</tt> on
your repository. However, the new addressing, checksumming and packing scheme
will not be used in that case but only in repositories that got created as format
7. For best performance and to enable all features, it is recommended to
perform a full
<a href="http://svnbook.red-bean.com/en/1.7/svn.reposadmin.maint.html#svn.reposadmin.maint.migrate.svnadmin">
dump / load</a> cycle. You can tell whether all format 7 features are enabled
by looking for <tt>FSFS Logical Addressing: yes</tt> in the output of
<tt>svnadmin info</tt>: if that line is printed, then the repository has
all format 7 features enabled.
</p>
<div class="notice">
<p><span style="color: red"><b>WARNING:</b></span> <b>Server restart
required!</b> Replacing an existing repository with one rebuilt from a
dump or restored from backup requires a server restart. This is true for
any repository format. Alternatively, you may store the new repository in
a different directory and redirect the Apache configuration to use that
instead of the old one; <tt>svnserve</tt> does not offer that option.</p>
</div>
<p>The next subsection compares performance characteristics of repositories
created directly as format 7 with those upgraded to format 7 from older formats.
</p>
</div> <!-- fsfs-format7 -->
<div class="h4" id="format7-comparison">
<h4>Service quality
<a class="sectionlink" href="#format7-comparison"
title="Link to this section">¶</a>
</h4>
<p>The FSFS changes in 1.9 are aimed at better service quality and do not
translate into client-side features being available or not. Depending on
your setup, some of the improvements may be relevant while others are not.
This table shall help you decide what features are relevant to your environment
and whether you need to upgrade or dump and load your repositories to reap
the benefits.
</p>
<table border="1">
<tr>
<th>Feature</th>
<th>Format 6<br />or older</th>
<th>Upgraded to format 7<br />from older formats</th>
<th>Created as format 7<br />not packed</th>
<th>Created as format 7<br />packed</th></tr>
<tr>
<td>Reduction in dynamic memory usage<sup>1</sup></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td>Saturate 10Gb networks from SVN caches<sup>2</sup></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td>Saturate 1Gb networks from OS caches<sup>3</sup></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td><tt>svnadmin pack</tt> does not block commits</td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td>Full checksum coverage of revision data<sup>4</sup></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td><a href="#svnadmin-verify" title="svnadmin verify">Quick
verification</a> to find external corruption<sup>5</sup></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: green"><b>yes</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td>Fast access to cold data on disk<sup>6</sup></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: red"><b>no</b></span></td>
<td><span style="color: green"><b>yes</b></span></td></tr>
<tr>
<td colspan="5"><p><sup>1</sup> Where feasible, temporary buffers have a
fixed maximum size now. Other temporary containers have been reduced
in memory consumption.</p>
<p><sup>2</sup> If almost all requests can be served from SVN fulltext
caches etc., an 8-core server running Apache can saturate a 10Gb network
with uncompressed data. It will take 20+ concurrent checkout or export
requests to generate that load.</p>
<p><sup>3</sup> If virtually all requests can be served from the OS file
cache, a 4-core server running Apache can saturate a 1Gb network with
uncompressed data. It will take 2 or more concurrent checkout or export
requests to generate that load.</p>
<p><sup>4</sup> Not only user file contents, directories and properties
are protected by checksums but also the meta-data tying them together.
This only detects external corruption caused by rogue scripts, hard
disk failure etc. and will not help against internal corruption caused
by faulty SVN logic.</p>
<p><sup>5</sup> Verifies a repository at several 100MB/s and does not
slow down with increasing number of revisions. This allows for a much
faster health check after system failure.</p>
<p><sup>6</sup> Core feature of format 7. Revision data is read about
twice as fast as with older formats. Assuming reading data from disk
being 10x slower than from OS caches and a mere 10% OS cache misses,
this translates into 30% higher overall throughput with format 7 over
previous formats.</p>
</td></tr>
</table>
<p>Most users will want to not only <tt>svnadmin upgrade</tt> to migrate
their repositories but to eventually migrate them to format 7. For some,
it will be the fast verification feature, others will need the disk I/O
improvements. Note that the key I/O characteristics here is the
<a href="https://en.wikipedia.org/wiki/Bandwidth-delay_product">Bandwidth
Delay Product</a> of your storage, which is usually between 100kB and 1MB.
Even with SSDs you will see a speed-up, unless your storage bandwidth is
severely limited.
</p>
<p>There is no appreciable difference in CPU usage between the new format
and the older ones. Hence, the few setups that work almost entirely from
RAM due to very large caches will see little extra performance with format
7. These environments will still benefit from the improved checksum coverage
and the support for quick verification.
</p>
<div class="notice">
<p>Make sure to run <tt>svnadmin pack</tt> on your format 7 repositories
at regular intervals. Otherwise, you'll waste performance.
</p>
</div>
</div> <!-- format7-comparison -->
<div class="h4" id="format7-options">
<h4>Format 7 tuning options
<a class="sectionlink" href="#format7-options"
title="Link to this section">¶</a>
</h4>
<p>New configuration options are available for tuning read block sizes (format
7 only). They may be changed at any time without causing consistency issues
with existing revisions. Changing them is rarely necessary, but may result in
slightly improved performance with your specific storage backend or when
dealing with multi-TB repositories. See the commentary in <tt>fsfs.conf</tt>
for more information. (You may have to create a new repository to see
the documentation about these settings in <tt>fsfs.conf</tt>.)
</p>
<pre>
[io]
block-size = 256
l2p-page-size = 32768
p2l-page-size = 16384
</pre>
</div> <!-- fsfs-format7 -->
<div class="h4" id="fsfs-compression">
<h4>Zlib compresssion is now optional
<a class="sectionlink" href="#fsfs-compression"
title="Link to this section">¶</a>
</h4>
<p>FSFS uses a combination of two methods to reduce on-disk data size. First,
we determine the changes (delta) against some previous version of the same file.
This process can be controlled by <tt>fsfs.conf</tt> settings since 1.8. The result
would then be compressed using ZIP/deflate. That relatively costly operation
limits commit speeds of large incompressible files. You may now specify the
compression level in <tt>fsfs.conf</tt> or disable compression entirely:
</p>
<pre>
[deltification]
compression-level = 0
</pre>
</div> <!-- fsfs-compression -->
<div class="h4" id="fsfs-defaults">
<h4>Changed deltification defaults
<a class="sectionlink" href="#fsfs-defaults"
title="Link to this section">¶</a>
</h4>
<p>Directory and property deltification are now enabled by default for FSFS
repositories in 1.6 format or newer. Various optimizations were added to the
delta creation code to minimize the read amplification effect and to provide
a net speedup when using deltification vs. not using it. Keep
<a href="#fsfs-caching">txdelta caches</a> enabled when using directories
deltification. Otherwise, you may suffer a significant performance hit.</p>
<p>To prevent Subversion 1.9 from deltifying properties and directories in
older format repositories, set the following options in the
repository’s <tt>fsfs.conf</tt> file:
</p>
<pre>
[deltification]
enable-dir-deltification = false
enable-props-deltification = false
</pre>
</div> <!-- fsfs-defaults -->
<div class="h4" id="fsfs-caching">
<h4>Changes to the caching
<a class="sectionlink" href="#fsfs-caching"
title="Link to this section">¶</a>
</h4>
<p>The caching logic has been enhanced to cope with the extra load caused by
the access indirection introduced in FSFS format 7. While most of this simply
means more net speed, some changes may affect your configuration settings.</p>
<ul>
<li>Fulltext and txdelta caching are now enabled by default for all servers
as well as for local repository access.</li>
<li>Revision property caching is disabled and the respective server option
will be ignored.</li>
<li>Directories 3x as large as in 1.8 can now be cached.</li>
<li>Caching is quasi-perfect on short time scales (requesting data equal or
less than approx. 10% of the cache size). This greatly improves
performance when e.g. many clients check out the same project.</li>
<li>Long-term caching is now priority-based with text deltas having the lowest
priority. This results in slower but more reliable heating up, i.e. it
takes multiple similar requests until all frequently used data is kept in
cache, but it will reach this point eventually while older releases might
not.</li>
</ul>
</div> <!-- fsfs-caching -->
</div> <!-- fsfs-improvements -->
<div class="h3" id="svnfsfs">
<h3><tt>svnfsfs</tt> – A low-level FSFS manipulation tool
<a class="sectionlink" href="#svnfsfs"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="svnfsfs-overview">
<h4>Overview
<a class="sectionlink" href="#svnfsfs-overview"
title="Link to this section">¶</a>
</h4>
<p>Where the <tt>svnadmin</tt> tool covers typical administrative tasks
in a mostly back-end agnostic way, <tt>svnfsfs</tt> is a specialist tool
for analyzing and manipulating of FSFS repositories. It is not intended
for everyday use.
</p>
</div> <!-- svnfsfs-overview -->
<div class="h4" id="svnfsfs-stats">
<h4><tt>stats</tt> sub-command replacing the <tt>fsfs-stats</tt> tool
<a class="sectionlink" href="#svnfsfs-stats"
title="Link to this section">¶</a>
</h4>
<p>The <tt>fsfs-stats</tt> tool first released with Subversion 1.8 has
been replaced by the <tt>svnfsfs stats</tt> sub-command and is no longer
part of Subversion 1.9. Both produce similar output.
</p>
</div> <!-- svnfsfs-stats -->
<div class="h4" id="svnfsfs-index-manipulation">
<h4>Reading and writing format 7 indexes
<a class="sectionlink" href="#svnfsfs-index-manipulation"
title="Link to this section">¶</a>
</h4>
<p>During forensics or data recovery, it is necessary for experts to
directly "look into" the raw database files. While the FSFS on-disk
format is fully documented, the indirect addressing and reordering
added in format 7 makes it hard for humans to trace internal references.
This is where the <tt>svnfsfs dump-index</tt> sub-command is used.
It produces a table describing all items in revision and pack files:
</p>
<pre>
$ svnfsfs dump-index /path/to/repo -r0
Start Length Type Revision Item Checksum
0 11 drep 0 3 60232b75
11 59 node 0 2 403dbe48
6a 1 chgs 0 1 f28a4f1d
</pre>
<p>Because the index information must always match the actual file
contents, updating the index data after every revision / pack file
manipulation is mandatory in format 7. <tt>svnfsfs load-index</tt>
allows you to do that. It consumes the same table format as produced
above, except that the checksum field is optional and will be ignored
if given. See <a href="#svnfsfs-issues">the known issues list</a>
for problems in released versions of that tool.
</p>
<div class="notice">
<p><span style="color: red"><b>WARNING:</b></span> Be sure to
create a backup of your repository before trying to manipulate
it through <tt>svnfsfs</tt> !</p>
</div>
</div> <!-- svnfsfs-index-manipulation -->
<div class="h4" id="svnfsfs-issues">
<h4>Known issues
<a class="sectionlink" href="#svnfsfs-issues"
title="Link to this section">¶</a>
</h4>
<p>In 1.9.0, the <tt>svnfsfs load-index</tt> does not work as described
in its documentation. The following restrictions and workarounds apply:
</p>
<ul>
<li>The lines must be sorted by offset (first column).</li>
<li>The item number (5th column) must be given as hexadecimal. However,
<tt>svnfsfs dump-index</tt> produces decimal numbers in that column.
</li>
<li>The first entry must refer to the first revision in the pack file.
This is a non-issue for unpacked revisions. A simple solution is
inserting a line for empty section of length 0:
<pre>
Start Length Type Revision Item
0 0 none 3000 0
0 25a chgs 3999 1
25a 3b9 chgs 3998 1
...
</pre>
</li>
</ul>
<p>These problems have been fixed in 1.9.1.
</p>
</div> <!-- svnfsfs-issues -->
</div> <!-- svnfsfs -->
<div class="h3" id="fsx">
<h3>FSX – A new experimental repository backend
<a class="sectionlink" href="#fsx"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="fsx-overview">
<h4>Overview
<a class="sectionlink" href="#fsx-overview"
title="Link to this section">¶</a>
</h4>
<p>Since its inception 10 years ago, FSFS has been improved greatly and the
<a href="#fsfs-format7">improvements provided with format 7</a> are another
major step forward. However, there are limits to what can be done in a
meaningful and backward compatible way. FSX is being designed to overcome
these limitations. Here some of the intended improvements:
</p>
<ul>
<li>90% reduction in metadata overhead.</li>
<li>Efficient handling of very large files.</li>
<li>Higher overall compression rates, in particular for office-style
documents.</li>
<li>Information required for log and merge operations is more readily
available.</li>
<li>O(1) handling of large directories.</li>
<li>Versioned revision properties.</li>
<li>Partitionable storage.</li>
<li>Arbitrary meta data storage and indexing facilities.</li>
</ul>
<p>Development of FSX was started as a fork of FSFS to guarantee
functional completeness and testability. The current code still contains
remnants of FSFS legacy code and not all of the above improvements have been
implemented yet. Later releases will close the gap and remove transitional
code.
</p>
<div class="notice">
<p><span style="color: red"><b>WARNING:</b></span> FSX is <b>NOT</b> production
ready. DO NOT USE IT – unless you have read this section carefully and
understand the limitations of FSX in Subversion 1.9.</p>
</div>
</div> <!-- fsx-overview -->
<div class="h4" id="fsx-usage-scenarios">
<h4>Usage scenarios
<a class="sectionlink" href="#fsx-usage-scenarios"
title="Link to this section">¶</a>
</h4>
<p>FSX is nowhere near as stable and reliable as FSFS. Furthermore, there will
be no support for 1.9-style FSX repositories in 1.10
(see <a href="#fsx-incompatibility">Incompatibility</a>). Think, therefore,
of all data in a FSX repository as being potentially corrupt. Its improved
performance and storage characteristics, though, might make FSX a viable
option for the following use-cases:</p>
<ul>
<li>Running analysis or reporting tools whose output does not need to be 100%
reliable. Use FSX as a high-speed data source in a read-only mirror.</li>
<li>Investigate how FSX may fit into your future infrastructure. How well
does it perform with your data set concerning disk, I/O, RAM and CPU
usage?</li>
</ul>
<p></p>
<div class="notice">
<p>If you experiment with FSX, please <a href="/mailing-lists">let
us know</a> your findings. This is your chance to get your
use-case covered before storage format and principles of
operation are set in stone.</p>
</div>
</div> <!-- fsx-usage-scenarios -->
<div class="h4" id="fsx-incompatibility">
<h4>Incompatibility
<a class="sectionlink" href="#fsx-incompatibility"
title="Link to this section">¶</a>
</h4>
<p>The FSX code and storage representation is in an intermediate state with
respect to the feature set that its developers have in mind. For as long as
it keeps its experimental status, there will be neither forward nor backward
compatibility between FSX repositories of different Subversion feature releases.
Subversion 1.10 and later will recognize 1.9 FSX repositories and error out
on them. You may use <a href="http://svnbook.red-bean.com/en/1.7/svn.reposadmin.maint.html#svn.reposadmin.maint.migrate.svnadmin">
dump and load</a> to upgrade an FSX repository from one release to another.</p>
<p>Dump and load is also the only upgrade path between FSFS and FSX.</p>
<p>Finally, there is no guarantee that FSX will eventually be released at all;
as an experimental backend, we make no promise that future releases will
support reading or writing FSX repositories.</p>
</div> <!-- fsx-incompatibility -->
</div> <!-- fsx -->
</div> <!-- new-features -->
<div class="h2" id="enhancements">
<h2>Enhancements and Bugfixes
<a class="sectionlink" href="#enhancements"
title="Link to this section">¶</a>
</h2>
<!-- Don't need to highlight every bugfix, just major ones which aren't in
any patch release. -->
<div class="h3" id="cmdline">
<h3>Command-line client improvements (<em>client</em>)
<a class="sectionlink" href="#cmdline"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="svn-auth">
<h4>New sub-command <tt>svn auth</tt>
<a class="sectionlink" href="#svn-auth"
title="Link to this section">¶</a>
</h4>
<p>The new <tt>svn auth</tt> sub-command can be used to view or remove
authentication credentials saved in any of the supported password caches.
Authentication credentials include usernames, passwords,
SSL certificates, and SSL client-certificate passphrases.</p>
<p>Specific credentials can be selected with an arbitrary number of pattern
arguments which are matched against the attributes of each credential.
For example, view cached SSL certificates for the <i>apache.org</i> domain,
matched via credential kind (svn.ssl.server) and authentication realm and
certificate subject (apache.org):
</p>
<pre>
$ svn auth svn.ssl.server apache.org
------------------------------------------------------------------------
Credential kind: svn.ssl.server
Authentication realm: https://svn.us.apache.org:443
Subject: C=US, ST=Maryland, L=Forest Hill, O=The Apache Software Foundation, OU=Infrastructure, CN=*.apache.org
Valid from: 2015-04-29 02:00:00 +0200 (Wed, 29 Apr 2015)
Valid until: 2017-04-30 01:59:59 +0200 (Sun, 30 Apr 2017)
Issuer: C=US, O=Symantec Corporation, OU=Symantec Trust Network, CN=Symantec Class 3 Secure Server CA - G4
Fingerprint: 4ad722dd0442043657d176f9c81aab66094d4223
Hostnames: *.apache.org
Automatic certificate validity check failed because:
The certificate's Common Name (hostname) does not match the remote hostname.
Credentials cache in '~/.subversion' contains 1 matching credentials
</pre>
<p>For more information, see <tt>svn help auth</tt>.</p>
</div> <!-- svn-auth -->
<div class="h4" id="svn-info-item">
<h4><tt>svn info --show-item=<i>arg</i> [--no-newline]</tt>
<a class="sectionlink" href="#svn-info-item"
title="Link to this section">¶</a>
</h4>
<p>The <tt>svn info</tt> command can now display the value of one of the fields
and nothing else, for easier consumption by scripts.</p>
<p>Subversion 1.8 and earlier had two output modes: the default, human-oriented
output, mode and the XML mode for scripted use. Subversion 1.9 adds a third
output mode, whereby exactly one attribute will be displayed:</p>
<pre>
## Display the youngest revision of a repository:
% svn info --show-item=revision https://svn.apache.org/repos/asf/subversion/trunk
1693514
## Find the root directory of a working copy:
% svn info --show-item=wc-root
/home/jrandom/src/svn/trunk
</pre>
<p>Incidentally, Subversion will also attempt to offer the correct selector name
if the argument was misspelled:</p>
<pre>
% svn info --show-item=wcroot
svn: E205000: Try 'svn help info' for more information
svn: E205000: 'wcroot' is not a valid value for --show-item; did you mean 'wc-root'?
</pre>
<p>The list of valid arguments to <tt>--show-item</tt> may be found in its help
message, <tt>svn help info</tt>. As of 1.9, the valid values are
<tt>kind</tt>,
<tt>url</tt>,
<tt>relative-url</tt>,
<tt>repos-root-url</tt>,
<tt>repos-uuid</tt>,
<tt>revision</tt>,
<tt>last-changed-revision</tt>,
<tt>last-changed-date</tt>,
<tt>last-changed-author</tt>,
and
<tt>wc-root</tt>.</p>
<p>The <tt>--no-newline</tt> argument instructs <tt>svn</tt>
not to emit a cosmetic newline (<tt>\n</tt>) after the value.</p>
</div> <!-- svn-info-item -->
<div class="h4" id="svn-propget-no-newline">
<h4><tt>svn propget --no-newline</tt>
<a class="sectionlink" href="#svn-propget-no-newline"
title="Link to this section">¶</a>
</h4>
<p>The <tt>svn propget</tt> sub-command has a new <tt>--no-newline</tt> option.
It is equivalent to the old <tt>--strict</tt> option which is now deprecated.</p>
</div> <!-- svn-propget-no-newline -->
<div class="h4" id="svn-trust">
<h4>New HTTPS-related argument <tt>--trust-server-cert-failures</tt>
<a class="sectionlink" href="#svn-trust"
title="Link to this section">¶</a>
</h4>
<p>The new <tt>--trust-server-cert-failures</tt> option is intended to be used
by scripts which for some reason must accept SSL certificates which fail
validation for various reasons (e.g. expired certificates).</p>
<p>If at all possible, fixing a certificate problem is preferable to using
this option.</p>
<p>The <tt>--trust-server-cert-failures</tt> option only works in conjunction with
the <tt>--non-interactive</tt> option.</p>
<p>Previous versions of Subversion in non-interactive mode could only ignore
certificates with an unknown certificate authority, but expired or otherwise
invalid SSL certificates could not be accepted.</p>
</div> <!-- svn-trust -->
<div class="h4" id="svn-copy-pin-externals">
<h4>New <tt>--pin-externals</tt> option for <tt>svn copy</tt>
<a class="sectionlink" href="#svn-copy-pin-externals"
title="Link to this section">¶</a>
</h4>
<p>The <tt>svn copy</tt> sub-command now supports a new <tt>--pin-externals</tt> option.
Use of this option is recommended when creating tags.</p>
<p>If this option is used, <tt>svn copy</tt> pins the URLs in <tt>svn:externals</tt>
properties in the copied tree to their current revision, such that externals keep
their current contents when the copied tree is checked out at a later time.</p>
<p>Note that external references within externals cannot be pinned as this would require
<tt>svn copy</tt> to make commits to any foreign repositories referenced by externals.</p>
</div> <!-- svn-copy-pin-externals -->
<div class="h4" id="svn-cleanup-options">
<h4>New options for <tt>svn cleanup</tt>
<a class="sectionlink" href="#svn-cleanup-options"
title="Link to this section">¶</a>
</h4>
<p>The <tt>svn cleanup</tt> command has new <tt>--remove-unversioned</tt>
and <tt>--remove-ignored</tt> options which can be used to remove unversioned
and ignored files from the working copy.</p>
<p><tt>svn cleanup</tt> can now recurse into externals with the new
<tt>--include-externals</tt> option.</p>
</div> <!-- svn-cleanup-options-->
<div class="h4" id="svn-resolver-m">
<h4>Interactive conflict resolver changes
<a class="sectionlink" href="#svn-resolver-m"
title="Link to this section">¶</a>
</h4>
<p>In the interactive conflict resolver, the <tt>(m) merge</tt> command now
tries an external file merge tool if one is defined. Else the internal file
merge tool is used.</p>
<p>In Subversion 1.8, the <tt>(m) merge</tt> command always triggered the
internal file merge tool. The <tt>(i) internal merge tool</tt> command was
added to Subversion 1.9 and has the old meaning of the <tt>(m) merge</tt>
command.</p>
</div> <!-- svn-resolver-m -->
<div class="h4" id="svn-status-r">
<h4><tt>svn status</tt> now takes <tt>--revision</tt> (<tt>-r</tt>)
<a class="sectionlink" href="#svn-status-r"
title="Link to this section">¶</a>
</h4>
<p>The <tt>status</tt> command, when given the <tt>--show-updates</tt>
(<tt>-u</tt>) flag, can now compare the working copy to specific remote
revision, given by the <tt>-r</tt> (<tt>--revision</tt>) flag. (Previously,
the remote revision would default to HEAD.)</p>
</div> <!-- svn-status-r -->
</div> <!-- cmdline -->
<div class="h3" id="server-side-improvements">
<h3>Server-side improvements
<a class="sectionlink" href="#server-side-improvements"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="fewer-ood-conditions">
<h4>Committing the result of large merges
<a class="sectionlink" href="#fewer-ood-conditions"
title="Link to this section">¶</a>
</h4>
<p>Our best practices suggest that projects should branch and merge
at the project root level. Each merge will then usually change the
<tt>svn:mergeinfo</tt> property at the project base folder. To commit
that change, pre-1.9 servers require the client to have the latest
version of that base folder. Whenever there is a commit in that tree,
its base folder will get a new revision as well, though. Thus, in
large, busy projects, it is likely that by the time a large merge commit
would actually have reached its finalization phase, some other commit
got through and the merge commit is rejected for being out of date.
</p>
<p>Subversion 1.9 now allows to modify directory properties based on
old revisions as long as the directory contents itself did no change.
Directory contents changes would either be property changes, added or
removed entries. Sub-tree or file contents changes no longer prevent
the property change from going through. Of course, true file and tree
change conflicts will still result in out-of-date errors.
</p>
<p>This new behavior is not restricted to <tt>svn:mergeinfo</tt> changes
but applies to any directory properties. Changes to <tt>svn:ignore</tt>
are another common scenario previously prone to update / commit /
out-of-date races.
</p>
</div> <!-- fewer-ood-conditions -->
<div class="h4" id="rate-limiting-svnserve">
<h4>Rate limiting <tt>svnserve</tt>
<a class="sectionlink" href="#rate-limiting-svnserve"
title="Link to this section">¶</a>
</h4>
<p>In threaded mode, <tt>svnserve</tt> starts one thread per network
connection - potentially consuming a large amount of resources.
Subversion 1.9 now uses a thread pool with a configurable minimum and
maximum number of threads. Use the command line options
<tt>--min-threads</tt> and <tt>--max-threads</tt> if the defaults
don't suite your needs.
</p>
<div class="notice">
<p>Once there are more connections than threads, the threads will serve
incoming requests in a round-robin fashion. If all those requests are
long-running reports like checkout or export, connections with waiting
requests may eventually time out.</p>
</div>
<p>Whether or not the new options are available depends on the platform
and APR capabilities. Also, the default for <tt>--max-threads</tt> is
lower on 32 bit systems than on 64 bit ones. Run <tt>svnserve --help</tt>
to see your system's defaults and whether the options are available at all.
</p>
</div> <!-- rate-limiting-svnserve -->
</div> <!-- server-side-improvements -->
<div class="h3" id="svnadmin-improvements">
<h3><tt>svnadmin</tt> changes and improvements
<a class="sectionlink" href="#svnadmin-improvements"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="svnadmin-info">
<h4>New sub-command <tt>svnadmin info</tt>
<a class="sectionlink" href="#svnadmin-info"
title="Link to this section">¶</a>
</h4>
<p>This prints detailed format information for the given repository.
</p>
<pre>
$ svnadmin info /repos/apache/
Path: /repos/apache
UUID: ac336b0e-000b-11e0-b354-23d019ddd9ed
Repository Format: 5
Compatible With Version: 1.8.0
Repository Capability: mergeinfo
Filesystem Type: fsfs
Filesystem Format: 6
FSFS Sharded: yes
FSFS Shard Size: 1000
FSFS Shards Packed: 1631/1631
FSFS Logical Addressing: no
Configuration File: /repos/apache/db/fsfs.conf
</pre>
</div> <!-- svnadmin-info -->
<div class="h4" id="svnadmin-pack">
<h4><tt>svnadmin pack</tt>
<a class="sectionlink" href="#svnadmin-pack"
title="Link to this section">¶</a>
</h4>
<p>Packing now takes a cache size parameter (<tt>-M</tt>) which is used for
efficient operation on <a href="#fsfs-format7">FSFS format 7 repositories</a>.
</p>
<pre>
$ svnadmin pack -M 1000 /path/to/repository
</pre>
<p></p>
<div class="notice">
<p>Packing is paramount to FSFS format 7 performance; do it often. To make
this feasible, packing FSFS format 7 repositories will no longer block
commits for the whole time of its execution. Instead, individual commits may
now get delayed by much shorter periods of time, usually by less than one
second.</p>
</div>
</div> <!-- svnadmin-pack -->
<div class="h4" id="svnadmin-verify">
<h4><tt>svnadmin verify</tt>
<a class="sectionlink" href="#svnadmin-verify"
title="Link to this section">¶</a>
</h4>
<p>Verification will terminate by default once a problem has been found. The
new <tt>--keep-going</tt> option instructs svnadmin to continue with the next
revision such that multiple issues may be found in a single run. If a revision
has multiple issues and depending on the verification logic, still only the
first problem may be reported.</p>
<p>The new <tt>--check-normalization</tt> option reports any path names
within the same directory or svn:mergeinfo property which differ only
in character representation (e.g. Unicode precomposed and decomposed
character representations), but are otherwise identical.</p>
<p>Thorough verification is expensive and becomes slower as the repository
history grows. The new <tt>--metadata-only</tt> flag will skip the expensive
internal consistency checks and reconstruction of all user data.
In format 7 repositories, this will still perform a quick on-disk checksum
test of all data in rev / pack files but will only detect cases where
external forces (storage crash, rogue scripts etc.) modified committed data.
Also, the checksums are weaker (about a 1 in a billion chance that a random
change remains undetected) than the ones used to protect the user data. If
you suspect internal repository corruption caused by a bug within SVN itself,
you still need to run a full verification.</p>
</div> <!-- svnadmin-verify -->
<div class="h4" id="svnadmin-revprop">
<h4><tt>svnadmin setrevprop --transaction</tt> and
<tt>svnadmin delrevprop</tt>
<a class="sectionlink" href="#svnadmin-revprop"
title="Link to this section">¶</a>
</h4>
<p>The <tt>setrevprop</tt> command now takes the <tt>--transaction</tt> flag.
It can be used from <tt>pre-commit</tt> hooks to set revision properties
on the transaction (commit-in-progress) before it becomes a commit.</p>
<p>The new <tt>delrevprop</tt> command deletes a revision property from either
a revision or a transaction. It complements <tt>setrevprop</tt> which adds
or modifies revprops.</p>
</div> <!-- svnadmin-revprop -->
<div class="h4" id="svnadmin-load-ignore-dates">
<h4><tt>svnadmin load --ignore-dates</tt>
<a class="sectionlink" href="#svnadmin-load-ignore-dates"
title="Link to this section">¶</a>
</h4>
<p>The <tt>svnadmin load</tt> command has a new flag, <tt>--ignore-dates</tt>,
which causes it to ignore revision datestamps (<tt>svn:date</tt>) in the input
dumpfile.</p>
</div> <!-- load-ignore-dates-revprop -->
</div> <!-- svnadmin-improvements -->
<div class="h3" id="svnbench-improvements">
<h3><tt>svnbench</tt> changes and improvements
<a class="sectionlink" href="#svnbench-improvements"
title="Link to this section">¶</a>
</h3>
<div class="h4" id="svnbench-renamed">
<h4>Tool renamed from <tt>svn-bench</tt> to <tt>svnbench</tt>
<a class="sectionlink" href="#svnbench-renamed"
title="Link to this section">¶</a>
</h4>
<p>With Subversion 1.9 this tool is now part of the standard set of SVN
binaries. In keeping with the existing programs, it has been renamed to
<tt>svnbench</tt>.</p>
</div> <!-- svnbench-renamed -->
<div class="h4" id="svnbench-null-blame">
<h4>New sub-command <tt>svnbench null-blame</tt>
<a class="sectionlink" href="#svnbench-null-blame"
title="Link to this section">¶</a>
</h4>
<p>To investigate bottlenecks in <tt>svn blame</tt>, we added a protocol
driver variant of it to <tt>svnbench</tt>. The new <tt>null-blame</tt>
sub-command requests the same data from the server as the normal command
line client and shows a summary of the amount of data received.</p>
<pre>
$ svnbench null-blame -g http://example.org/repo/path/to/file
34 revisions
31 deltas
1,161,077 bytes in deltas
</pre>
</div> <!-- svnbench-null-blame -->
</div> <!-- svnbench-improvements -->
<div class="h3" id="three-way-conflict-markers">
<h3>Three-way conflict display, and <tt>diff3</tt> enhancements
<a class="sectionlink" href="#three-way-conflict-markers"
title="Link to this section">¶</a>
</h3>
<p>When a text conflict occurs (and is not resolved by the interactive conflicts
resolver during <tt>svn update</tt>, <tt>svn switch</tt> or <tt>svn merge</tt>),
<em>conflicts markers</em> are written into the conflicted file. Previous versions
of Subversion would render conflict markers as follows:</p>
<pre>
Unconflicted lines
<<<<<<< .mine
Contents of the file in the working copy (including local modifications)
=======
Contents of the file in the revision being updated to
>>>>>>> .r2
Unconflicted lines
</pre>
<p>As of Subversion 1.9, conflict markers would be rendered with information on
the base (called "older" in diff3 parlance):</p>
<pre>
Unconflicted lines
<<<<<<< .mine
Contents of the file in the working copy (including local modifications)
||||||| .r1
Contents of the file in the working copy's BASE revision
=======
Contents of the file in the revision being updated to
>>>>>>> .r2
Unconflicted lines
</pre>
<p>Here, one resolves the conflict by manually applying to the
<tt><<<<<<<</tt> hunk the same changes that would transform
the <tt>|||||||</tt> hunk into the <tt>>>>>>>></tt> hunk.
For example, the following conflict:</p>
<pre>
Unconflicted lines
<<<<<<< .mine
"Hello hello, world!"
||||||| .r1
"Hello, world!"
=======
"Hello, ${name}!"
>>>>>>> .r2
Unconflicted lines
</pre>
<p>should be resolved to:</p>
<pre>
Unconflicted lines
"Hello hello, ${name}!"
Unconflicted lines
</pre>
<p>The three-way conflict display was already used by property conflicts and
by the interactive conflicts resolver in previous releases of Subversion.</p>
<p>The old, two-way conflict markers output can be obtained by setting
<tt>diff3-cmd</tt> in the <a
href="http://svnbook.red-bean.com/nightly/en/svn.advanced.confarea.html"
>Subversion runtime configuration</a> (or via the <tt>--config-option</tt>
or <tt>--diff3-cmd</tt> command-line options) to a <tt>diff3</tt>
command that generates two-way conflict markers. Your system may already
include such a <tt>diff3</tt> program; one is also included with Subversion
and can be installed via <tt>make install-tools</tt> (Unix) or by building the
<tt>diff3</tt> or <tt>__MORE__</tt> targets (Windows). On a typical Unix system,
simply setting <tt>diff3-cmd=diff3</tt> will restore two-way conflict markers.</p>
<p>Subversion 1.9 adds to the included <tt>diff3</tt> program
a <tt>--conflict-style</tt> marker that can be used to explicitly choose among
two-way conflict markers, three-way conflict markers, and a few other options.
That program can be used independently of Subversion anywhere a <tt>diff3</tt>
command is needed.</p>
</div> <!-- three-way-conflict-markers -->
<div class="h3" id="prospective-blame">
<h3>Prospective blame
<a class="sectionlink" href="#prospective-blame"
title="Link to this section">¶</a>
</h3>
<p>The <tt>blame</tt> command can now show not only when the <em>last</em>
change to each line of a given file was, but also when the <em>next</em> change
will be.</p>
<p>For example, to see for each line in revision 3 of README.txt what the
next revision that changed (or removed) that line would be, run
<tt>svn blame -r HEAD:3 README.txt</tt>. (You may need to pass a
<!-- TODO: link points to nightly (no 1.9 book branch yet) -->
<a href="http://svnbook.red-bean.com/nightly/en/svn.advanced.pegrevs.html">peg
revision</a> if the file had been renamed since r3.)</p>
<p>In the <tt>blame</tt> command, the range <tt>-r M:N</tt> always means
"display information about the file at revision N". If the range is
"forward" (M<N) then the normal blame algorithm is used, displaying for each
line in the file when it was added or last changed; if the range is "reversed"
(M>N) then the above-described sense is used, describing for each line in rN
when it was first changed (or deleted) after rN and before rM.</p>
<p>Here is an example, from Subversion's own repository. The autoconf macro
<tt>SVN_CHECK_FOR_DUNDER_BUILTINS</tt> was
<a href="https://svn.apache.org/viewvc/subversion/trunk/build/ac-macros/svn-macros.m4?view=markup&pathrev=1509167#l167"
>present in r1509167</a> but is not present in HEAD. The <tt>blame</tt>
command can determine the revision in which the macro was removed:</p>
<pre>
% svn blame -r HEAD:1509167 svn-macros.m4
⋮
1509168 danielsh AC_DEFUN([SVN_CHECK_FOR_DUNDER_BUILTINS],
</pre>
<p>And indeed, <tt>svn diff -c r1509168</tt> shows that revision
<a href="https://svn.apache.org/viewvc/subversion/trunk/build/ac-macros/svn-macros.m4?r1=1509168&r2=1509167&pathrev=1509168&diff_format=h"
>deleting the definition of the macro</a>.</p>
</div> <!-- prospective-blame -->
<div class="h3" id="lock-http-pipelining">
<h3>Lock HTTP pipelining
<a class="sectionlink" href="#lock-http-pipelining"
title="Link to this section">¶</a>
</h3>
<p>When locking, or unlocking, multiple files in a single operation
over HTTP the client will use HTTP pipelining for the individual
WebDAV LOCK and UNLOCK requests. This makes the operation faster
particularly on connections with large network latency. While HTTP
pipelining is new for LOCK and UNLOCK the client was already using it
for GET requests.</p>
</div> <!-- lock-http-pipelining -->
<div class="h3" id="locking-multiple-files">
<h3>Locking multiple files
<a class="sectionlink" href="#locking-multiple-files"
title="Link to this section">¶</a>
</h3>
<p>Subversion locks, the locks that prevent commits from other working
copies, are stored in the repository. When adding or removing locks
the FSFS backend can now operate on several locks at once. This
reduces the amount of disk IO when handling multiple locks and is
significant when the total number of locks in the repository is large,
100,000 say.</p>
<p>The default behaviour for commits is to automatically release locks
after a successful commit and this takes advantage of the more
efficient lock process. In previous releases the disk IO involved in
releasing the locks would sometimes be greater than that involved in
creating the new revision.</p>
<p>Clients using the svn:// protocol will also benefit from the more
efficient lock handling when locking or unlocking multiple files in a
single operation. Clients using HTTP will not get this benefit since
the client still sends multiple, pipelined, LOCK and UNLOCK requests,
one for each file.</p>
</div> <!-- locking-multiple-files -->
<div class="h3" id="locking-post-hooks">
<h3>Multiple paths in post-lock and post-unlock hooks
<a class="sectionlink" href="#locking-post-hooks"
title="Link to this section">¶</a>
</h3>
<p>The post-lock and post-unlock hooks receive multiple paths via
standard input. In previous releases the repository backends always
operated on a single path at a time so only one path was ever passed
to the hook. In 1.9 when multiple paths are locked or unlocked in a
single operation multiple paths will be passed to the hook.</p>
<p>The pre-lock and pre-unlock hooks continue to be passed a single
path as a parameter.</p>
</div> <!-- locking-post-hooks -->
<div class="h3" id="apache-cache-status">
<h3>Apache FSFS cache status
<a class="sectionlink" href="#apache-cache-status"
title="Link to this section">¶</a>
</h3>
<p>Subversion's Apache module, mod_dav_svn, can display statistics
that describe the status of the FSFS cache for the running Apache
instance. To enable this define a Location block in the Apache
configuration file:</p>
<pre>
<Location /svn-status>
SetHandler svn-status
</Location>
</pre>
<p>Visiting the Location with a web browser will display statistics
about the FSFS cache for the running Apache instance. If Apache is
configured to use multiple processes, most Unix deployments, the
statistics will only apply to the process that served the GET request
and repeating the request will cause different processes to be
queried.</p>
</div> <!-- apache-cache-status -->
</div> <!-- enhancements -->
<div class="h2" id="issues">
<h2>Known issues in the release
<a class="sectionlink" href="#issues"
title="Link to this section">¶</a>
</h2>
<p>There are some known issues in the Subversion 1.9 releases. These
may be fixed in later 1.9.x releases.</p>
<div class="h3" id="no-op-changes">
<h3>No-op changes no longer dumped by '<tt>svnadmin dump</tt>'
<a class="sectionlink" href="#no-op-changes"
title="Link to this section">¶</a>
</h3>
<p>See <a href="https://issues.apache.org/jira/browse/SVN-4598">issue #4598 "No-op changes no longer dumped by 'svnadmin dump' in 1.9"</a>.
</p>
<p>It has always been possible, in atypical cases, for a commit to mark a
file as 'changed' without actually changing the file's text and/or
properties to a different value. Starting from 1.9.0, <tt>svnadmin dump</tt>
still outputs a record for such a file, including a header saying that the
action is 'change', but no longer appends a block describing the new text
for the file. (And similarly for properties, perhaps? TBD.) When
<tt>svnadmin load</tt> (1.8 or 1.9) reads this dumpfile, it does not record
any change in the repository for such a file.
</p>
<p>One user-visible effect is that, after dump and load, 'svn log -v' will
no longer list the path of such a file in its list of 'changed paths'.
</p>
<p>A fix for this problem has been included in the 1.9.3 release.
</p>
</div> <!-- no-op-changes -->
<div class="h3" id="httpv1-commit-race">
<h3>"Out of date" errors when committing over HTTPv1
<a class="sectionlink" href="#httpv1-commit-race"
title="Link to this section">¶</a>
</h3>
<p>If there are concurrent commits to the same repository, they may
randomly fail with an "out of date" error message without actually
being in conflict. The problem presents itself to the user like any
legitimate out-of-date condition and retrying the commit as usual
will fix the problem.
</p>
<p>This problem is not new to Subversion 1.9 and limited to repositories
with high commit frequencies. Triggering it requires either pre-1.7
clients, a pre-1.7 server or a server that has HTTPv2 explicitly disabled
via the <tt>SVNAdvertiseV2Protocol off</tt> option. To avoid the problem,
consider upgrading clients and configuring the server to use the HTTPv2
protocol.
</p>
<p>svnserve and local repository access are not affected.
</p>
</div> <!-- httpv1-commit-race -->
<div class="h3" id="shattered-sha1">
<h3>Subversion is unable to store SHA1 collisions
<a class="sectionlink" href="#shattered-sha1"
title="Link to this section">¶</a>
</h3>
<p>
Subversion up to and including 1.9.5 can incorrectly store files with
different content but the same SHA1 checksum. We recommend that all
servers update to 1.9.6 and enable representation sharing.
See our <a href="/security/sha1-advisory.txt">SHA1 advisory</a> for details.
</p>
</div> <!-- shattered-sha1 -->
<div class="h3" id="svn-4722">
<h3>Commit can fail with an undeserved SHA1 collision error
<a class="sectionlink" href="#svn-4722"
title="Link to this section">¶</a>
</h3>
<p>When using a Subversion 1.9.6 or 1.9.7 server, a commit may fail
with an undeserved SHA1 collision error: "E160000: SHA1 of reps
… and … matches (…) but contents differ." This
bug affects the 1.9.6 and 1.9.7 releases.</p>
<p>See <a href="https://issues.apache.org/jira/browse/SVN-4722?issueNumber=4722"
>issue 4722, "checksum fail during commit when delta is 16K"</a>.
</p>
<p>A fix for this problem has been included in the 1.9.9 release
(1.9.8 was not publicly released).</p>
</div> <!-- svn-4722 -->
</div> <!-- issues -->
<div class="h2" id="troubleshooting">
<h2>Troubleshooting issues specific to this release
<a class="sectionlink" href="#troubleshooting"
title="Link to this section">¶</a>
</h2>
<p>Subversion 1.9 introduces new features and makes use of new techniques
which can trigger problems not encountered in previous versions. In contrast to
known issues, things listed here are not due to some bug or issue in Subversion
itself and therefore cannot be fixed with a new patch release.
This section lists all known problems and provides instructions to solve them,
if they occur.</p>
<div class="h3" id="http-pipelining-issue">
<h3>Lock/Unlock errors related to HTTP pipelining
<a class="sectionlink" href="#http-pipelining-issue"
title="Link to this section">¶</a>
</h3>
<p>Subversion 1.9.0 introduces the use of HTTP pipelining for locking/unlocking
multiple files. While SVN detects whether HTTP pipelining is supported (and
falls back to non HTTP pipelining mode, if it isn't), issues can arrise, if
there are flaws or bugs with any of the protocols/applications involved in
processing pipelined HTTP requests.</p>
<p>Especially, if there are older proxies present in the network topology, it's
possible that you run into issues, since being a technology which was
introduced in HTTP/1.1 (and the full performance benefit is not expected unless
you are using HTTP/2), this feature might have not been extensively tested by
your proxy vendor.</p>
<p>To troubleshoot whether the proxy is causing an issue, try to lock/unlock
multiple files bypassing the proxy. If that works, please get in touch with
the proxy vendor to notify him about the problem and ask for support.</p>
<p>It's also appreciated, if you would let the SVN developers know about the
effected proxy via the users mailing list so this troubleshooting section can
be updated.</p>
<p>At the moment there is one potentially known proprietary proxy running into
this issue: Java-SSL-tunnel. See
<a href="https://groups.google.com/d/msg/tortoisesvn/h72AhfjwcbQ/RfTVgbXqCwAJ"
>Tortoise SVN mailing list</a>.
</p>
</div> <!-- http-pipelining-issue -->
</div> <!-- troubleshooting -->
<div class="h2" id="svn-1.7-deprecation">
<h2>Subversion 1.7.x series no longer supported
<a class="sectionlink" href="#svn-1.7-deprecation"
title="Link to this section">¶</a>
</h2>
<p>The Subversion 1.7.x line is no longer supported. This doesn't
mean that your 1.7 installation is doomed; if it works well and is all
you need, that's fine. "No longer supported" just means we've stopped
accepting bug reports against 1.7.x versions, and will not make any
more 1.7.x bugfix releases.</p>
</div> <!-- svn-1.7-deprecation -->
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