[jboss-cvs] JBoss Messaging SVN: r3865 - branches/Branch_JBossMessaging_1_4_0_SP3_CP/docs/userguide/en/modules.

[jboss-cvs-commits at lists.jboss.org]

Author: timfox
Date: 2008-03-11 09:09:50 -0400 (Tue, 11 Mar 2008)
New Revision: 3865

Modified:
   branches/Branch_JBossMessaging_1_4_0_SP3_CP/docs/userguide/en/modules/configuration.xml
Log:
Tweaks to docs about prefetchSize


Modified: branches/Branch_JBossMessaging_1_4_0_SP3_CP/docs/userguide/en/modules/configuration.xml
===================================================================
--- branches/Branch_JBossMessaging_1_4_0_SP3_CP/docs/userguide/en/modules/configuration.xml	2008-03-11 13:08:26 UTC (rev 3864)
+++ branches/Branch_JBossMessaging_1_4_0_SP3_CP/docs/userguide/en/modules/configuration.xml	2008-03-11 13:09:50 UTC (rev 3865)
@@ -1751,20 +1751,15 @@
          </section>
          <section id="conf.connectionfactory.attributes.prefetchsize">
             <title>PrefetchSize</title>
-            <para>Each client side consumer maintains a local buffer of
-            messages from which it consumes. The server typically sends
-            messages as fast as it can to the consumer, and when the consumer
-            is full it sends the server a "stop" message to say it is full.
-            When it clears enough space it sends a "start" message to ask the
-            server to continue sending messages. The prefetchSize determines
-            the size of this buffer. Larger values give better
-            throughput.</para>
+	    <para>This parameter specifies the window size in numbers of messages, for consumer flow control.
+		    The window size determines the number of messages a server can send to a consumer without blocking.
+        Each consumer maintains a buffer of messages from which it consumes. Please note that TCP also implements its own flow control, so if you set this to too large a number, then the TCP window size may be hit before the prefetchSize, which can cause writes to block.</para>
          </section>
          <section id="conf.connectionfactory.attributes.slowconsumers">
             <title>SlowConsumers</title>
-            <para>If you have very slow consumers, then you probably want to
-            make sure they don't buffer any messages. Since this can prevent
-            them from being consumed by faster consumers.</para>
+	    <para>If you have very slow consumers, then you probably want to make
+		    sure they don't buffer any messages. Since this can prevent them from
+        being consumed by faster consumers. Setting this to true is equivalent to setting PrefetchSize to 1</para>
          </section>
          <section id="conf.connectionfactory.attributes.tckstrictbehavior">
             <title>StrictTck</title>