geode-core/src/main/java/org/apache/geode/internal/tcp/package.html - geode - Git at Google

 <!--
 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

      http://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.
 -->
 <html>
 <body>
 Contains TCP/IP communications conduit
 <br>
 <br>
 <br>
 <p>The tcp/ip conduit is designed to be used in one way:</p>

 </p>1) The conduit is used by the GemFire
 {@link org.apache.geode.distributed.internal.membership.MembershipManager}
 when true multicast messaging is not needed and disable-tcp is not
 set to true, which is the default setting.  When used in this way, the
 conduit manages the serialization and transmission of
 {@link org.apache.geode.distributed.internal.DistributionMessage}
 objects from one system to another.  The
 {@link org.apache.geode.distributed.internal.membership.MembershipManager}
 routes outgoing messages to TCPConduit and handles receipt of messages
 received by TCPConduit {@link org.apache.geode.internal.tcp.Connection "Connections"}.
 <hr>

 <p>Messaging uses DataSerializer serialization to send messages (and
 receive replies).
 <hr>

 <p>The GemFire Cache implementation initializes a <code>TCPConduit</code> when the
 cache is initialized.
 <code>TCPConduit</code>s created by the
 cache use a wildcard bind to select a server port unless the property
 tcpServerPort is set.  If you're building a service using <code>TCPConduit</code>
 you may want to use a fixed port so that if your service exits it can
 restart on the same port.</p>

 <hr>

 <p>The design of the conduit is fairly simple.  <code>TCPConduit</code> owns the
 {@link java.net.ServerSocket} that accepts connections from other conduits.
 {@link org.apache.geode.internal.tcp.Connection "Connections"}
 are kept in a
 {@link org.apache.geode.internal.tcp.ConnectionTable ConnectionTable}.
 </p>

 <p>The use of NIO can be turned off with the property <code>p2p.oldIO=true</code>.
 This will force the use of sockets instead of socket channels.
 Each <code>Connection</code> always creates a reader thread for pulling information out
 of its socket.</p>

 <p>NIO and oldIO communications are interoperable</p>

 <p><code>TCPConduit</code> is used to send and receive messages using
 endpoint <code>Stubs</code> holding target host/port information. The conduit
 uses this information to select the correct <code>Connection</code>,
 or to create a new one if necessary.  When sending a message, the
 conduit passes the message to the <code>Connection</code> and waits
 until transmission is complete before returning.  Messages and
 responses received by a <code>Connection</code> are passed to the
 <code>TCPConduit</code> which routes them to their final
 destination.</p>

 <p>When a message is received from another conduit it is deserialized
 and examined.  If it is a <code>DistributionMessage</code>, the message is delegated
 to the <code>DirectChannel</code> held by the <code>MembershipManager</code>.
 </p>

    TCPConduit  ----->  ConnectionTable
                        |     |     |
                        v     v     v
                         Connections
 </code></pre>
 <hr>

 <p>When a Connection is formed between two conduits, the client side
 (the one initiating the connection) transmits its <code>TCPConduit's</code>
 <code>ServerSocket</code> port.  This port is used to identify the connection instead
 of the regular socket port.  This allows all <code>Connection</code> objects to be
 identified by their associated server ports and makes connection management
 much simpler.</p>

 <hr>
 <p>Other property settings that affect the conduit:</p><pre>

   p2p.tcpBufferSize - the size of operating system buffers on the tcp socket.
       outgoing messages.  The default is 32768.

   p2p.readerBufferSize - the size of the buffer used by reader threads
       to buffer incoming data.  The default is 32768.

   p2p.VERBOSE - turn on verbose logging at finer and finest log settings

   p2p.defaultLogLevel - level of logging to use if there is no distribution
       manager or gemfire log writer.  The value is "info", "config", "fine"
       etc

   p2p.DEBUG - turn on VERBOSE and defaultLogLevel of "finest"

   p2p.oldIO - turn off the use of java.nio for I/O operations.  If there is
       a custom socket implementation being used in the VM that doesn't support
       NIO you might want to use this property.

   p2p.useSSL - causes the conduit to use the javax.ssl JSSE factory to create
       its server socket.  This also sets p2p.oldIO=true since SSL sockets
       don't currently seem to support NIO.  TCPConduit has the method
       getSSLSession(serverId) that can be used to retrieve the SSL
       session for a given connection.  The serverId argument is a stub.

   p2p.idleConnectionTimeout - how long a thread owned connection can be idle
       before it will be closed.

 </pre>
 <p>Some of these properties are instance-specific and can be set when you
 create the conduit by passing a {@link java.util.Properties} object with the settings. When
 you use this form of the <code>TCPConduit</code> constructor, the conduit will not
 search for these settings in system properties:</p><pre>

       p2p.tcpBufferSize
       p2p.idleConnectionTimeout

 </pre>
 </body>
 </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

	http://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.
	-->
	<html>
	<body>
	Contains TCP/IP communications conduit
	<br>
	<br>
	<br>
	<p>The tcp/ip conduit is designed to be used in one way:</p>

	</p>1) The conduit is used by the GemFire
	{@link org.apache.geode.distributed.internal.membership.MembershipManager}
	when true multicast messaging is not needed and disable-tcp is not
	set to true, which is the default setting. When used in this way, the
	conduit manages the serialization and transmission of
	{@link org.apache.geode.distributed.internal.DistributionMessage}
	objects from one system to another. The
	{@link org.apache.geode.distributed.internal.membership.MembershipManager}
	routes outgoing messages to TCPConduit and handles receipt of messages
	received by TCPConduit {@link org.apache.geode.internal.tcp.Connection "Connections"}.
	<hr>

	<p>Messaging uses DataSerializer serialization to send messages (and
	receive replies).
	<hr>

	<p>The GemFire Cache implementation initializes a <code>TCPConduit</code> when the
	cache is initialized.
	<code>TCPConduit</code>s created by the
	cache use a wildcard bind to select a server port unless the property
	tcpServerPort is set. If you're building a service using <code>TCPConduit</code>
	you may want to use a fixed port so that if your service exits it can
	restart on the same port.</p>

	<hr>

	<p>The design of the conduit is fairly simple. <code>TCPConduit</code> owns the
	{@link java.net.ServerSocket} that accepts connections from other conduits.
	{@link org.apache.geode.internal.tcp.Connection "Connections"}
	are kept in a
	{@link org.apache.geode.internal.tcp.ConnectionTable ConnectionTable}.
	</p>

	<p>The use of NIO can be turned off with the property <code>p2p.oldIO=true</code>.
	This will force the use of sockets instead of socket channels.
	Each <code>Connection</code> always creates a reader thread for pulling information out
	of its socket.</p>

	<p>NIO and oldIO communications are interoperable</p>

	<p><code>TCPConduit</code> is used to send and receive messages using
	endpoint <code>Stubs</code> holding target host/port information. The conduit
	uses this information to select the correct <code>Connection</code>,
	or to create a new one if necessary. When sending a message, the
	conduit passes the message to the <code>Connection</code> and waits
	until transmission is complete before returning. Messages and
	responses received by a <code>Connection</code> are passed to the
	<code>TCPConduit</code> which routes them to their final
	destination.</p>

	<p>When a message is received from another conduit it is deserialized
	and examined. If it is a <code>DistributionMessage</code>, the message is delegated
	to the <code>DirectChannel</code> held by the <code>MembershipManager</code>.
	</p>

	TCPConduit -----> ConnectionTable
	\| \| \|
	v v v
	Connections
	</code></pre>
	<hr>

	<p>When a Connection is formed between two conduits, the client side
	(the one initiating the connection) transmits its <code>TCPConduit's</code>
	<code>ServerSocket</code> port. This port is used to identify the connection instead
	of the regular socket port. This allows all <code>Connection</code> objects to be
	identified by their associated server ports and makes connection management
	much simpler.</p>

	<hr>
	<p>Other property settings that affect the conduit:</p><pre>

	p2p.tcpBufferSize - the size of operating system buffers on the tcp socket.
	outgoing messages. The default is 32768.

	p2p.readerBufferSize - the size of the buffer used by reader threads
	to buffer incoming data. The default is 32768.

	p2p.VERBOSE - turn on verbose logging at finer and finest log settings

	p2p.defaultLogLevel - level of logging to use if there is no distribution
	manager or gemfire log writer. The value is "info", "config", "fine"
	etc

	p2p.DEBUG - turn on VERBOSE and defaultLogLevel of "finest"

	p2p.oldIO - turn off the use of java.nio for I/O operations. If there is
	a custom socket implementation being used in the VM that doesn't support
	NIO you might want to use this property.

	p2p.useSSL - causes the conduit to use the javax.ssl JSSE factory to create
	its server socket. This also sets p2p.oldIO=true since SSL sockets
	don't currently seem to support NIO. TCPConduit has the method
	getSSLSession(serverId) that can be used to retrieve the SSL
	session for a given connection. The serverId argument is a stub.

	p2p.idleConnectionTimeout - how long a thread owned connection can be idle
	before it will be closed.

	</pre>
	<p>Some of these properties are instance-specific and can be set when you
	create the conduit by passing a {@link java.util.Properties} object with the settings. When
	you use this form of the <code>TCPConduit</code> constructor, the conduit will not
	search for these settings in system properties:</p><pre>

	p2p.tcpBufferSize
	p2p.idleConnectionTimeout

	</pre>
	</body>
	</html>