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Posted to commits@subversion.apache.org by st...@apache.org on 2015/07/27 16:57:03 UTC
svn commit: r1692893 - /subversion/site/publish/docs/release-notes/1.9.html
Author: stefan2
Date: Mon Jul 27 14:57:03 2015
New Revision: 1692893
URL: http://svn.apache.org/r1692893
Log:
Some fine-tuning to the FSFS improvements section of the 1.9 release notes.
* publish/docs/release-notes/1.9.html
(fsfs-format7): Block read is opt-in. Tweak wording in various places
without actually changing the meaning.
(format7-comparison): Remove percentages where they are not helpful for
users. Minor grammar fixes.
(fsfs-caching): Don't give conflicting advice about txdelta caching.
Modified:
subversion/site/publish/docs/release-notes/1.9.html
Modified: subversion/site/publish/docs/release-notes/1.9.html
URL: http://svn.apache.org/viewvc/subversion/site/publish/docs/release-notes/1.9.html?rev=1692893&r1=1692892&r2=1692893&view=diff
==============================================================================
--- subversion/site/publish/docs/release-notes/1.9.html (original)
+++ subversion/site/publish/docs/release-notes/1.9.html Mon Jul 27 14:57:03 2015
@@ -323,19 +323,19 @@ Major changes include:
<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 will now fetch data in larger blocks of configurable size
- (64kB by default) and cache all their contents. This eliminates much of
- the OS overhead.</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>Support commits while packing is in progress.</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 those but only in repositories that got created as format
+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/1.9/svn.reposadmin.maint.html#svn.reposadmin.maint.migrate.svnadmin">
@@ -344,8 +344,9 @@ by looking for <tt>FSFS Logical Addressi
<tt>svnadmin info</tt>: if that line is printed, then the repository has
all format 7 features enabled.
-<p>The next subsection compares performance of repositories created directly as
-format 7 and of repositories upgraded to format 7 from older formats.</p>
+<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 -->
@@ -358,7 +359,7 @@ format 7 and of repositories upgraded
<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 may help you decide what features are relevant to your environment
+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>
@@ -417,18 +418,17 @@ the benefits.
<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, i.e. well over
- 90%, 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 (>95%), 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>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
+ 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
@@ -445,7 +445,7 @@ the benefits.
<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 is the
+improvements. Note that the key I/O characteristics here is the
<a href="http://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
@@ -454,7 +454,7 @@ severely limited.
<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
+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>
@@ -550,7 +550,7 @@ means more net speed, some changes may a
<ul>
<li>Fulltext and txdelta caching are now enabled by default for all servers
- as well as local repository access.</li>
+ 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>
@@ -561,8 +561,7 @@ means more net speed, some changes may a
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. You may disable txdelta caching to reduce cache load and heat caches
- more quickly.</li>
+ not.</li>
</ul>
</div> <!-- fsfs-caching -->