| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- |
| |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You under the Apache License, Version 2.0 |
| (the "License"); you may not use this file except in compliance with |
| the License. You may obtain a copy of the License at |
| |
| https://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| --> |
| <head> |
| <title>Apache Felix - Dependency Manager - Performance Tuning</title> |
| <link rel="icon" href="/res/favicon.ico"> |
| <link rel="stylesheet" href="/res/site.css" type="text/css" media="all"> |
| <link rel="stylesheet" href="/res/codehilite.css" type="text/css" media="all"> |
| <meta http-equiv="Content-Type" content="text/html;charset=UTF-8"> |
| </head> |
| <body> |
| <div class="title"> |
| <div class="logo"> |
| <a href="https://felix.apache.org/"> |
| <img border="0" alt="Apache Felix" src="/res/logo.png"> |
| </a> |
| </div> |
| <div class="header"> |
| <a href="https://www.apache.org/"> |
| <img border="0" alt="Apache" src="/res/apache.png"> |
| </a> |
| </div> |
| </div> |
| |
| <div class="menu"> |
| <style type="text/css"> |
| /* The following code is added by mdx_elementid.py |
| It was originally lifted from http://subversion.apache.org/style/site.css */ |
| /* |
| * Hide class="elementid-permalink", except when an enclosing heading |
| * has the :hover property. |
| */ |
| .headerlink, .elementid-permalink { |
| visibility: hidden; |
| } |
| h2:hover > .headerlink, h3:hover > .headerlink, h1:hover > .headerlink, h6:hover > .headerlink, h4:hover > .headerlink, h5:hover > .headerlink, dt:hover > .elementid-permalink { visibility: visible }</style> |
| <p><a href="/news.html">News</a> <br /> |
| <a href="/license.html">License</a> <br /> |
| <a href="/downloads.cgi">Downloads</a> <br /> |
| <a href="/documentation.html">Documentation</a> <br /> |
| <a href="/documentation/community/project-info.html">Project Info</a> <br /> |
| <a href="/documentation/community/contributing.html">Contributing</a> <br /> |
| <a href="/sitemap.html">Site Map</a> <br /> |
| <a href="https://www.apache.org/">ASF</a> <br /> |
| <a href="https://www.apache.org/security/">Security</a> <br /> |
| <a href="https://www.apache.org/foundation/sponsorship.html">Sponsorship</a> <br /> |
| <a href="https://www.apache.org/foundation/thanks.html">Sponsors</a> </p> |
| <iframe |
| src="https://www.apache.org/ads/button.html" |
| style="border-width:0; float: left" |
| frameborder="0" |
| scrolling="no" |
| width="135" |
| height="135"> |
| </iframe> |
| </div> |
| |
| <div class="main"> |
| <div class="breadcrump" style="font-size: 80%;"> |
| <a href="/">Home</a> » <a href="/documentation.html">Documentation</a> » <a href="/documentation/subprojects/apache-felix-dependency-manager.html">Apache Felix Dependency Manager</a> |
| </div> |
| |
| <h1>Dependency Manager - Performance Tuning</h1> |
| <style type="text/css"> |
| /* The following code is added by mdx_elementid.py |
| It was originally lifted from http://subversion.apache.org/style/site.css */ |
| /* |
| * Hide class="elementid-permalink", except when an enclosing heading |
| * has the :hover property. |
| */ |
| .headerlink, .elementid-permalink { |
| visibility: hidden; |
| } |
| h2:hover > .headerlink, h3:hover > .headerlink, h1:hover > .headerlink, h6:hover > .headerlink, h4:hover > .headerlink, h5:hover > .headerlink, dt:hover > .elementid-permalink { visibility: visible }</style> |
| <p>To further tune the performance of an application using Dependency Manager and a lot of services, we created the concept of filter indices. They work similarly to the way indices speed up relational database queries and are explained below.</p> |
| <h2 id="filter-indices">Filter Indices<a class="headerlink" href="#filter-indices" title="Permanent link">¶</a></h2> |
| <p>Filter indices allow you to speed up the service resolution process by skipping the services registry, in favor of a fast index on given service properties.</p> |
| <p>The Dependency Manager will look for a set of filter indices in the <code>org.apache.felix.dependencymanager.filterindex</code> system property. This system property uses the following syntax,</p> |
| <div class="codehilite"><pre><span class="n">property</span><span class="o">-</span><span class="n">index</span> <span class="p">::=</span> <span class="n">service</span><span class="o">-</span><span class="n">property</span> <span class="o">|</span> <span class="n">service</span><span class="o">-</span><span class="n">property</span> <span class="s">','</span> <span class="n">property</span><span class="o">-</span><span class="n">index</span> |
| <span class="n">index</span> <span class="p">::=</span> <span class="s">'*aspect*'</span> <span class="o">|</span> <span class="s">'*adapter*'</span> <span class="o">|</span> <span class="n">property</span><span class="o">-</span><span class="n">index</span> |
| <span class="n">indices</span> <span class="p">::=</span> <span class="n">index</span> <span class="o">|</span> <span class="n">indices</span> <span class="s">';'</span> <span class="n">index</span> |
| </pre></div> |
| |
| |
| <p>The implementation ships with three kinds of index implementations.</p> |
| <ul> |
| <li><em>Service property indices</em> are based on a set of service properties, like a multi-column index in a database. </li> |
| <li><em>Aspect indices</em> work with Dependency Manager Aspect services, and will provide indexing for the specific filters that they use.</li> |
| <li><em>Adapter indices</em> work like Aspect indices, but for Adapter services.</li> |
| </ul> |
| <h3 id="performance">Performance<a class="headerlink" href="#performance" title="Permanent link">¶</a></h3> |
| <p>The index isn't free, but reduces the linear (and wasteful) filter-based lookup to an indexed log(n) lookup. You can expect noticeable speedup if you have at least several hundred services.</p> |
| <h3 id="examples">Examples<a class="headerlink" href="#examples" title="Permanent link">¶</a></h3> |
| <div class="codehilite"><pre><span class="o">-</span><span class="n">Dorg</span><span class="p">.</span><span class="n">apache</span><span class="p">.</span><span class="n">felix</span><span class="p">.</span><span class="n">dependencymanager</span><span class="p">.</span><span class="n">filterindex</span><span class="p">=</span><span class="n">objectClass</span> |
| </pre></div> |
| |
| |
| <p>Sets an index on <code>objectClass</code>, speeding up lookups for any filter that contains an <code>objectClass</code> in its filter (all regular services do).</p> |
| <div class="codehilite"><pre><span class="o">-</span><span class="n">Dorg</span><span class="p">.</span><span class="n">apache</span><span class="p">.</span><span class="n">felix</span><span class="p">.</span><span class="n">dependencymanager</span><span class="p">.</span><span class="n">filterindex</span><span class="p">=</span><span class="n">objectClass</span><span class="p">,</span><span class="n">id</span> |
| </pre></div> |
| |
| |
| <p>This filter helps if you have a lot of similar services, identified by some <code>id</code>.</p> |
| <div class="codehilite"><pre><span class="o">-</span><span class="n">Dorg</span><span class="p">.</span><span class="n">apache</span><span class="p">.</span><span class="n">felix</span><span class="p">.</span><span class="n">dependencymanager</span><span class="p">.</span><span class="n">filterindex</span><span class="p">=</span><span class="n">objectClass</span><span class="p">,</span><span class="n">id</span><span class="p">;</span><span class="n">objectClass</span><span class="p">,</span><span class="n">ipAddress</span> |
| </pre></div> |
| |
| |
| <p>This is a set of two filter indices, helping when you have one set of services that has an <code>id</code>, and another set that uses an <code>ipAddress</code> for identification.</p> |
| <div class="codehilite"><pre><span class="o">-</span><span class="n">Dorg</span><span class="p">.</span><span class="n">apache</span><span class="p">.</span><span class="n">felix</span><span class="p">.</span><span class="n">dependencymanager</span><span class="p">.</span><span class="n">filterindex</span><span class="p">=</span><span class="o">*</span><span class="n">aspect</span><span class="o">*</span> |
| </pre></div> |
| |
| |
| <p>Provides indexing for all Aspect services.</p> |
| <div class="timestamp" style="margin-top: 30px; font-size: 80%; text-align: right;"> |
| Rev. 1665812 by marrs on Wed, 11 Mar 2015 09:02:04 +0000 |
| </div> |
| <div class="trademarkFooter"> |
| Apache Felix, Felix, Apache, the Apache feather logo, and the Apache Felix project |
| logo are trademarks of The Apache Software Foundation. All other marks mentioned |
| may be trademarks or registered trademarks of their respective owners. |
| </div> |
| </div> |
| </body> |
| </html> |
