Regarding CachingTcpConnectionFactory

[yogya]

Hi


I am tring to implement a connection pool for tcp connections.


I went through the CachingTcpConnectionFactory on

https://github.com/garyrussell/sandb...onFactory.java


So I am doing this post just for clarify some questions.

<int-ip:tcp-connection-factory id="client"
		deserializer="deserializer" type="client" host="${socket.host}"
		port="${socket.port}" so-timeout="60000" />

<bean id="caching" class="com.infrastructure.connection.CachingTcpConnectionFactory">
	<constructor-arg ref="client" />
	<property name="poolSize" value="10" />
	<property name="availableTimeout" value="10000"/>
	
	</bean>



	<int-ip:tcp-outbound-gateway id="outGateway"
		request-channel="sendStringMessageChannel" reply-channel="recieveStringMessageChannel"
		connection-factory="caching" request-timeout="10000" reply-timeout="10000" />

If I am using the tcp-outbound-gateway instead of adapters is there any way to get the response if I returned the CachedConnection object which extends AbstractTcpConnectionInterceptor?

Do I have to register the sender and listner for the CachedConnection object?

Could you please guide me on this.


But with out returning the CachedConnection object I just return the TcpConnection object and I was able to get the response.

I cannot figure out how to overide the close() to add used connections to the available BlockingQueue and removed from the inUse Set if Im not returning a CachedConnection object which extends AbstractTcpConnectionInterceptor

So is there any way to overide the close() while using the tcp-outbound-gateway ?


Thanks in advance for any explanation on this.

[Gary Russell]

That was a prototype I wrote a long time ago; I was going to point you to the current implementation in 2.2 which will be out shortly (2.2.0.RC3 was released last week).

However, I see that the same problem occurs there too.

I have opened a bug: https://jira.springsource.org/browse/INT-2839

I'll work on it today.

[yogya]

I really appreciate your help. Thanks a lot.

[Gary Russell]

I have fixed the problem with the (now) standard caching connection factory in the 2.2 master branch

https://github.com/SpringSource/spri...ation/pull/686

The same technique MIGHT work with that old prototype in my sandbox, but I would recommend you try with 2.2.0.BUILD-SNAPSHOT; barring any final hiccups, we are planning to release 2.2.0.RELEASE in the next day or so.

[yogya]

Thanks.

I was able to implement the connection pool using CachingClientConnectionFactory.


This is the configurations that I used.

<int-ip:tcp-connection-factory id="tcpConnectionFactory"
		deserializer="deserializer" type="client" host="${socket.host}"
		port="${socket.port}" so-keep-alive="true"/>

	<int-ip:tcp-outbound-gateway id="outboundGateway"
		request-channel="sendStringMessageChannel" reply-channel="recieveStringMessageChannel"
		connection-factory="tcpConnectionPool" request-timeout="10000"
		reply-timeout="10000" />

	<bean id="tcpConnectionPool"
		class="org.springframework.integration.ip.tcp.connection.CachingClientConnectionFactory">
		<constructor-arg ref="tcpConnectionFactory" />
		<constructor-arg type="int"
			value="50" />
	</bean>

	<bean id="deserializer"
		class="com.infrastructure.connection.SocketInputStreamDeserializer" />

But I am experiencing an issue when using the app after a long idle time.

Caused by: java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:141)
        at org.springframework.integration.ip.tcp.serializer.ByteArrayCrLfSerializer.serialize(ByteArrayCrLfSerializer.java:74)
        at org.springframework.integration.ip.tcp.serializer.ByteArrayCrLfSerializer.serialize(ByteArrayCrLfSerializer.java:31)
        at org.springframework.integration.ip.tcp.connection.TcpNetConnection.send(TcpNetConnection.java:70)
        at org.springframework.integration.ip.tcp.connection.AbstractTcpConnectionInterceptor.send(AbstractTcpConnectionInterceptor.java:122)
        at org.springframework.integration.ip.tcp.TcpOutboundGateway.handleRequestMessage(TcpOutboundGateway.java:121)
        ... 92 more

Thanks in advance for any guidance related to this.

[Gary Russell]

Interesting; the so-keep-alive should cause the broken connection to be detected and, whenever we get a connection from the pool we check it's still open before handing it out.

I suppose there might be a race condition, depending on when the close happens.

You could add a retry advice to the outbound gateway to try again when this occurs.

http://static.springsource.org/sprin...r-advice-chain

[yogya]

Hi

Thanks a lot for your quick response.

If I do not set the so-keep-alive property what will happen?

[Gary Russell]

It depends on the network and exactly who/what is closing the connection.

If the server closes the connection, the client should always be told. However, if a switch/proxy simply drops the connection, or the server has a power failure, the client isn't told until he tries to send a message - keep alives are intended to avoid such situations - enabling the client to learn that a connection is dead. The actual keepalive behavior (how often they are sent etc) is configured by the operating system/tcp stack.

[yogya]

OK. I'll work on the previous solution and will get back to you on tomorrow.

Thanks.

WISH YOU A HAPPY NEW YEAR

[yogya]

Hi

I had add a retry advice and tested the app.So far I didn't get the broken pipe exception.

This is the configurations that I used.

<int-ip:tcp-connection-factory id="tcpConnectionFactory"
		deserializer="deserializer" type="client" host="${socket.host}"
		port="${socket.port}" so-keep-alive="true"/>

	<int-ip:tcp-outbound-gateway id="outboundGateway"
		request-channel="sendStringMessageChannel" reply-channel="recieveStringMessageChannel"
		connection-factory="tcpConnectionPool" request-timeout="10000"
		reply-timeout="10000" />

	<int:service-activator input-channel="input" ref="retryFailer"
		method="service">
		<int:request-handler-advice-chain>
			<bean
				class="org.springframework.integration.handler.advice.RequestHandlerRetryAdvice">
				<property name="recoveryCallback">
					<bean
						class="org.springframework.integration.handler.advice.ErrorMessageSendingRecoverer">
						<constructor-arg ref="connectionRetyErrorChannel" />
					</bean>
				</property>
			</bean>
		</int:request-handler-advice-chain>
	</int:service-activator>

	<bean id="retryFailer"
		class="com.infrastructure.connection.ConnectionRetry" />


	<bean id="tcpConnectionPool"
		class="org.springframework.integration.ip.tcp.connection.CachingClientConnectionFactory">
		<constructor-arg ref="tcpConnectionFactory" />
		<constructor-arg type="int"
			value="50" />
	</bean>

	<bean id="deserializer"
		class="com.infrastructure.connection.SocketInputStreamDeserializer" />

Thanks a lot for your guidance.