Author: gaohoward Date: 2010-05-05 04:00:38 -0400 (Wed, 05 May 2010) New Revision: 9199 Modified: branches/HnetQ_323_cn/docs/user-manual/zh/thread-pooling.xml Log: done Modified: branches/HnetQ_323_cn/docs/user-manual/zh/thread-pooling.xml =================================================================== --- branches/HnetQ_323_cn/docs/user-manual/zh/thread-pooling.xml 2010-05-05 03:10:14 UTC (rev 9198) +++ branches/HnetQ_323_cn/docs/user-manual/zh/thread-pooling.xml 2010-05-05 08:00:38 UTC (rev 9199) @@ -17,98 +17,74 @@ <!-- permitted by applicable law. --> <!-- ============================================================================= --> <chapter id="thread-pooling"> - <title>Thread management</title> - <para>This chapter describes how HornetQ uses and pools threads and how you can manage - them.</para> - <para>First we'll discuss how threads are managed and used on the server side, then we'll look - at the client side.</para> + <title>线程管理</title> + <para>本章讲述HornetQ如何使用线程池以及如何管理线程。</para> + <para>首先我们讨论在服务器端线程是如何被管理的，然后我们再讨论客户端的情况。</para> <section> - <title>Server-Side Thread Management</title> - <para>Each HornetQ Server maintains a single thread pool for general use, and a scheduled - thread pool for scheduled use. A Java scheduled thread pool cannot be configured to use - a standard thread pool, otherwise we could use a single thread pool for both scheduled - and non scheduled activity.</para> - <para>There are also a small number of other places where threads are used directly, we'll - discuss each in turn.</para> + <title>服务器端线程的管理</title> + <para>每个HornetQ服务器都有一个线程池作为一般线程使用，另外还有一个可计划线程池。Java的可计划线程池不能作为 + 标准的线程池使用，因此我们采用了两个单独的线程池。</para> + <para>另外在其它一些地方直接使用了线程，没有用线程池。我们将对这些线程作出解释。</para> <section id="server.scheduled.thread.pool"> - <title>Server Scheduled Thread Pool</title> - <para>The server scheduled thread pool is used for most activities on the server side - that require running periodically or with delays. It maps internally to a <literal - >java.util.concurrent.ScheduledThreadPoolExecutor</literal> instance.</para> - <para>The maximum number of thread used by this pool is configure in <literal - >hornetq-configuration.xml</literal> with the <literal - >scheduled-thread-pool-max-size</literal> parameter. The default value is - <literal>5</literal> threads. A small number of threads is usually sufficient - for this pool.</para> + <title>服务器端可计划线程池</title> + <para>服务器可计划线程池可以定期地或延迟地执行所交给的任务，它用来完成HornetQ中绝大部分这样的任务。 + 它内部使用的是一个 <literal + >java.util.concurrent.ScheduledThreadPoolExecutor</literal>实例。</para> + <para>最大线程数可以在<literal + >hornetq-configuration.xml</literal>文件中进行配置，参数名是<literal + >scheduled-thread-pool-max-size</literal>。默认值是<literal>5</literal>。 + 通常这个线程池不需要很大数量的线程。</para> </section> <section> - <title>General Purpose Server Thread Pool</title> - <para>This general purpose thread pool is used for most asynchronous actions on the - server side. It maps internally to a <literal - >java.util.concurrent.ThreadPoolExecutor</literal> instance.</para> - <para>The maximum number of thread used by this pool is configure in <literal - >hornetq-configuration.xml</literal> with the <literal - >thread-pool-max-size</literal> parameter.</para> - <para>If a value of <literal>-1</literal> is used this signifies that the thread pool - has no upper bound and new threads will be created on demand if there are enough - threads available to satisfy a request. If activity later subsides then threads are - timed-out and closed.</para> - <para>If a value of <literal>n</literal> where <literal>n</literal>is a positive integer - greater than zero is used this signifies that the thread pool is bounded. If more - requests come in and there are no free threads in the pool and the pool is full then - requests will block until a thread becomes available. It is recommended that a - bounded thread pool is used with caution since it can lead to dead-lock situations - if the upper bound is chosen to be too low.</para> - <para>The default value for <literal>thread-pool-max-size</literal> is <literal - >-1</literal>, i.e. the thread pool is unbounded.</para> - <para>See the <ulink + <title>服务器通用线程池</title> + <para>服务器端绝大部分的异步操作都是由这个线程池来完成的。在它的内部使用了一个<literal + >java.util.concurrent.ThreadPoolExecutor</literal>的实例。</para> + <para>这个线程池的最大线程数在<literal>hornetq-configuration.xml</literal>文件中配置，相应的参数名为<literal + >thread-pool-max-size</literal>。</para> + <para>如果将参数设为<literal>-1</literal>则表示该线程池没有线程限制。也就是说当线程不够用时，线程池就 + 会创建新的线程。当任务不多时，空闲的线程将会超时并被关闭。</para> + <para>如果这个参数的值是一个大于零的整数<literal>n</literal>，则该线程池的线程数是有限的。当所有线程都 + 处于忙的状态并且线程数已经达到n时，任何新的请求都将被阻塞直到有线程空闲为止。在设置线程上限时，我们建议 + 要非常谨慎。因为如何线程数量过低会造成死锁情况的发生。</para> + <para><literal>thread-pool-max-size</literal>的默认值是<literal + >-1</literal>，即线程池没有上限。</para> + <para>参见<ulink url="http://java.sun.com/j2se/1.5.0/docs/api/java/util/concurrent/Th... - >J2SE javadoc</ulink> for more information on unbounded (cached), and bounded - (fixed) thread pools.</para> + >J2SE javadoc</ulink>有关无边界（缓存）和有边界（固定）线程池的解释。</para> </section> <section> - <title>Expiry Reaper Thread</title> - <para>A single thread is also used on the server side to scan for expired messages in - queues. We cannot use either of the thread pools for this since this thread needs to - run at its own configurable priority.</para> - <para>For more information on configuring the reaper, please see <xref - linkend="message-expiry"/>.</para> + <title>过期回收线程</title> + <para>HornetQ使用一个单独的线程来扫描队列中过期的消息。由于这个线程需要自己的优先级配置，所以不能使用上述的 + 任何一个线程池。</para> + <para>关于回收线程的配置请参阅<xref linkend="message-expiry"/>。</para> </section> <section> - <title>Asynchronous IO</title> - <para>Asynchronous IO has a thread pool for receiving and dispatching events out of the - native layer. You will find it on a thread dump with the prefix - HornetQ-AIO-poller-pool. HornetQ uses one thread per opened file on the journal - (there is usually one).</para> - <para>There is also a single thread used to invoke writes on libaio. We do that to avoid - context switching on libaio what would cause performance issues. You will find this - thread on a thread dump with the prefix HornetQ-AIO-writer-pool.</para> + <title>异步IO</title> + <para>HornetQ使用一个线程池来进行异步IO的操作，包括事件的接收和发送。这些线程的名字都是以 + HornetQ-AIO-poller-pool为开头。每个打开的日志文件都对应有一个线程为其服务（通常只有 + 一个）。</para> + <para>还有一个单独的线程用于向libaio发送写请求。这样做是为了避免上下文转换带来的性能下降。该 + 线程的名字以HornetQ-AIO-writer-pool开头。</para> </section> </section> <section id="thread-pooling.client.side"> - <title>Client-Side Thread Management</title> - <para>On the client side, HornetQ maintains a single static scheduled thread pool and a - single static general thread pool for use by all clients using the same classloader in - that JVM instance.</para> - <para>The static scheduled thread pool has a maximum size of <literal>5</literal> threads, - and the general purpose thread pool has an unbounded maximum size.</para> - <para>If required HornetQ can also be configured so that each <literal - >ClientSessionFactory</literal> instance does not use these static pools but instead - maintains its own scheduled and general purpose pool. Any sessions created from that - <literal>ClientSessionFactory</literal> will use those pools instead.</para> - <para>To configure a <literal>ClientSessionFactory</literal> instance to use its own pools, - simply use the appropriate setter methods immediately after creation, for - example:</para> + <title>客户端线程管理</title> + <para>在客户端HornetQ有一个静态的可计划线程池和一个静态的通用线程池，它们在一个JVM中由同一个classloader装载的所有客户端 + 共同使用。</para> + <para>静态的可计划的线程池的最大线程数为 <literal>5</literal>，通用线程池则没有线程数限制。</para> + <para>如果需要还可以配置一个<literal + >ClientSessionFactory</literal>实例以使它拥有自己的可计划与通用线程池。通过这个工厂创建的会话都 + 将使用这些线程池。</para> + <para>要想配置<literal>ClientSessionFactory</literal>使用自己的线程池，只要调用它相应的方法取出可，如：</para> <programlisting>ClientSessionFactory myFactory = HornetQClient.createClientSessionFactory(...); myFactory.setUseGlobalPools(false); myFactory.setScheduledThreadPoolMaxSize(10); myFactory.setThreadPoolMaxSize(-1); </programlisting> - <para>If you're using the JMS API, you can set the same parameters on the ClientSessionFactory and use it to create the <literal - >ConnectionFactory</literal> instance, for example:</para> + <para>如果使用JMS，你可以先用同样的参数设置ClientSessionFactory，然后再用这样工厂创建<literal + >ConnectionFactory</literal>的实例。如：</para> <programlisting>ConnectionFactory myConnectionFactory = HornetQJMSClient.createConnectionFactory(myFactory); </programlisting> - <para>If you're using JNDI to instantiate <literal>HornetQConnectionFactory</literal> - instances, you can also set these parameters in the <literal>hornetq-jms.xml</literal> - file where you describe your connection factory, for example:</para> + <para>如果你使用JNDI来创建<literal>HornetQConnectionFactory</literal> + 实例，你还可以在<literal>hornetq-jms.xml</literal>文件中进行配置。如：</para> <programlisting>&lt;connection-factory name="ConnectionFactory"&gt; &lt;connectors> &lt;connector-ref connector-name="netty"/&gt;