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Skelta mode was the only supported mode in 1.0 (not new in 1.6), we switched neon to bulk mode later for performance reasons. Bert From: jcor...@apache.org Sent: =E2=80=8E20/=E2=80=8E06/=E2=80=8E2013 03:09 To: comm...@subversion.apache.org Subject: svn commit: r1494829 - /subversion/site/publish/docs/release-notes/1.8.html Author: jcorvel Date: Thu Jun 20 01:09:20 2013 New Revision: 1494829 URL: http://svn.apache.org/r1494829 Log: Add information about serf skelta mode and the configuration knobs involved to the 1.8 release notes. Patch by: lgo (tweaked by me) Modified: subversion/site/publish/docs/release-notes/1.8.html Modified: subversion/site/publish/docs/release-notes/1.8.html URL: http://svn.apache.org/viewvc/subversion/site/publish/docs/release-note= s/1.8.html?rev=3D1494829&r1=3D1494828&r2=3D1494829&view=3Ddiff =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D --- subversion/site/publish/docs/release-notes/1.8.html (original) +++ subversion/site/publish/docs/release-notes/1.8.html Thu Jun 20 01:09:20= 2013 @@ -401,24 +401,124 @@ TCP connections to the server. Clients using neon will also work fine with this configuration.</p> </div> =20 -<div class=3D"h4" id=3D"serf-server-log"> -<h4>Server logs larger with serf clients - <a class=3D"sectionlink" href=3D"#serf-server-log" +<div class=3D"h4" id=3D"serf-skelta-default"> +<h4>Skelta style updates are now the default + <a class=3D"sectionlink" href=3D"#serf-skelta-default" title=3D"Link to this section">¶</a> </h4> =20 -<p><em>This affects any server version, when accessed with a 1.8 -client.</em></p> +<p>The svn 1.8 client with serf defaults to skelta mode for update +operations (checkout, update, merge and export) instead of the bulk update= mode +used by previous versions. Skelta mode was introduced in Subversion 1.6.0 = and +improved in 1.8.0. It uses one HTTP request and response per resource that= needs +to be fetched from the server, whereas bulk update mode fetches all resour= ces in +one massive reponse.</p> + +<p>The main benefit of skelta mode is that it allows a correctly set up Ap= ache +server or intermediate proxy server to cache <tt>mod_dav_svn</tt>=C3=A2=C2= =80=C2=99s responses to +handle later requests from the cache. This results in improved performance= of +svn client operations and reduced CPU usage on the server side. It also al= lows +a more detailed audit of clients accessing resources in a Subversion +repository.</p> =20 -<p>Because serf clients issue a larger number of HTTP GET requests -than neon clients it is possible that serf clients cause quicker -growth of httpd server logs than neon clients do. As of 1.7.3,=20 -the httpd error logs may also grow more rapidly with serf clients -than with neon clients; see +<p>Skelta mode has some disadvantages:</p> +<ul> +<li>Apache server access log files will grow more quickly due to the large= r +number of requests and responses. As of 1.7.3, the httpd error logs may al= so +grow more rapidly with serf clients than with neon clients; see <a href=3D"http://svn.apache.org/viewvc?rev=3D1239697&view=3Drev"; ->r1239697</a>.</p> +>r1239697</a>.</li> +<li>Network traffic can increase drastically when Kerberos or NTLM +authentication is used, as these add a 2 - 4 KB header per HTTP request an= d +response.</li> +</ul> + +<p>This release introduces two options to control if the svn client will u= se +skelta or bulk update mode.</p> +<p> +<ul> +<li> For the server administrator: The <tt>SVNAllowBulkUpdates</tt> direct= ive for +<tt>mod_dav_svn</tt> now accepts <tt>Prefer</tt>. This will advise the svn +client to always use bulk update mode. All svn client versions with a defa= ult +configuration (see table) will respect this preference.</li> + +<li>For the user: Set the new option <tt>http-bulk-updates</tt> in the ser= vers +runtime configuration file to <em>yes</em> to force the use of bulk update= s, +<em>no</em> to never use bulk updates. The default option <em>auto</em> ma= kes +svn use skelta mode with a 1.8 server (unless it has <tt>SVNAllowBulkUpdat= es</tt> +set to <tt>Prefer</tt>), and bulk updates mode with +older servers and 1.8 servers which prefer bulk updates.</li> +</ul> +</p> + +<div class=3D"notice"> +<p>For 1.8 servers, set <strong>SVNAllowBulkUpdates</strong> to +<strong>Prefer</strong> if your server configuration does not allow an +intermediate caching server - on your side or on the client's side - to +successfully cache server responses.</p> +</div> + +<p>Table explaining the mode used between each combination of svn client a= nd +server version and relevant configuration directives:</p> + +<table border=3D"1"> + <tr> + <th></th> + <th colspan=3D"3">1.8 Server<br/>with SVNAllowBulkUpdates:</th> + <th colspan=3D"2">1.7 and older Server<br/>with SVNAllowBulkUpdates:</= th> + </tr> + <tr> + <th>Subversion Client</th> + <th>Off</th> + <th>On<sup>*</sup></th> + <th>Prefer</th> + <th>Off</th> + <th>On<sup>*</sup></th> + </tr> + <tr> + <td>1.8, <tt>http-bulk-updates: auto</tt><sup>*</sup></td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Bulk mode</td> + <td>Skelta mode</td> + <td>Bulk mode</td> + </tr> + <tr> + <td>1.8, <tt>http-bulk-updates: yes</tt></td> + <td>Skelta mode</td> + <td>Bulk mode</td> + <td>Bulk mode</td> + <td>Skelta mode</td> + <td>Bulk mode</td> + </tr> + <tr> + <td>1.8, <tt>http-bulk-updates: no</tt></td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + </tr> + <tr> + <td>1.7 and older with neon<sup>*</sup></td> + <td>Skelta mode</td> + <td>Bulk mode</td> + <td>Bulk mode</td> + <td>Skelta mode</td> + <td>Bulk mode</td> + </tr> + <tr> + <td>1.7 and older with serf</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + <td>Skelta mode</td> + </tr> +</table> +<p><sup>*</sup>Default configuration</p> =20 -</div> <!-- serf-server-log --> +</div> <!-- serf-skelta-default --> =20 </div> <!-- neon-deleted --> =20
