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https://issues.apache.org/jira/browse/PLC4X-326?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17449270#comment-17449270
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Christofer Dutz commented on PLC4X-326:
---------------------------------------
Hi DHANABALAN,
well the try() thing is a "try-with-resources" and the connection is a
"Closeable". So: yes it should close the connection automatically as soon as
you leave the try block.
However for a usecase like yours, we strongly suggest to use a
PooledConnection.
With Modbus the connection overhead isn't that bad, but it's always good to
re-use the connections.
Please have a look here:
[http://plc4x.apache.org/users/tools/connection-cache.html]
Please try this out.
Chris
> org.apache.plc4x.java.api.exceptions.PlcConnectionException: Error creating
> channel
> -----------------------------------------------------------------------------------
>
> Key: PLC4X-326
> URL: https://issues.apache.org/jira/browse/PLC4X-326
> Project: Apache PLC4X
> Issue Type: Bug
> Components: Driver-Modbus
> Affects Versions: 0.9.0
> Reporter: DHANABALAN DURAIRAJASIVAM
> Priority: Critical
>
> Hello All,
> I have used to poll the Modbus Registers every 10 Seconds
> and for modbus connection, I have used the connection Code from example
> given. (see below).
> _try (PlcConnection plcConnection = new
> PlcDriverManager().getConnection(connectionString)) \{ ... do something with
> the connection here ... }_
>
> _Above code created in a bean and bean has been called by camel producer
> every 10 sec._
> *The Question is ,does this above code close the connection itself when
> repeatedly called by new instance? or we need to handle connection close?*
> *Exception.*
> org.apache.plc4x.java.api.exceptions.PlcConnectionException: Error creating
> channel.
> at
> org.apache.plc4x.java.spi.connection.NettyChannelFactory.createChannel(NettyChannelFactory.java:130)
> at
> org.apache.plc4x.java.spi.connection.DefaultNettyPlcConnection.connect(DefaultNettyPlcConnection.java:121)
> at
> org.apache.plc4x.java.PlcDriverManager.getConnection(PlcDriverManager.java:74)
> at com.jtc.evcharger.bean.ModbusScan.GetEvChargerData(ModbusScan.java:82)
> at jdk.internal.reflect.GeneratedMethodAccessor47.invoke(Unknown Source)
> at
> java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
> at java.base/java.lang.reflect.Method.invoke(Unknown Source)
> at
> org.apache.camel.support.ObjectHelper.invokeMethodSafe(ObjectHelper.java:382)
> at org.apache.camel.component.bean.MethodInfo.invoke(MethodInfo.java:494)
> at
> org.apache.camel.component.bean.MethodInfo$1.doProceed(MethodInfo.java:316)
> at
> org.apache.camel.component.bean.MethodInfo$1.proceed(MethodInfo.java:286)
> at
> org.apache.camel.component.bean.AbstractBeanProcessor.process(AbstractBeanProcessor.java:146)
> at
> org.apache.camel.component.bean.BeanProcessor.process(BeanProcessor.java:81)
> at
> org.apache.camel.processor.errorhandler.RedeliveryErrorHandler$SimpleTask.run(RedeliveryErrorHandler.java:463)
> at
> org.apache.camel.impl.engine.DefaultReactiveExecutor$Worker.schedule(DefaultReactiveExecutor.java:179)
> at
> org.apache.camel.impl.engine.DefaultReactiveExecutor.scheduleMain(DefaultReactiveExecutor.java:64)
> at org.apache.camel.processor.Pipeline.process(Pipeline.java:184)
> at
> org.apache.camel.impl.engine.CamelInternalProcessor.process(CamelInternalProcessor.java:398)
> at
> org.apache.camel.component.timer.TimerConsumer.sendTimerExchange(TimerConsumer.java:210)
> at
> org.apache.camel.component.timer.TimerConsumer$1.run(TimerConsumer.java:76)
> at java.base/java.util.TimerThread.mainLoop(Unknown Source)
> at java.base/java.util.TimerThread.run(Unknown Source)
> Caused by: java.lang.IllegalStateException: failed to create a child event
> loop
> at
> io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:88)
> at
> io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:60)
> at
> io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:52)
> at
> io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:97)
> at
> io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:92)
> at
> io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:73)
> at
> io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:53)
> at
> io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:45)
> at
> org.apache.plc4x.java.spi.connection.NettyChannelFactory.getEventLoopGroup(NettyChannelFactory.java:86)
> at
> org.apache.plc4x.java.spi.connection.NettyChannelFactory.createChannel(NettyChannelFactory.java:94)
> ... 21 more
> Caused by: io.netty.channel.ChannelException: failed to open a new selector
> at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:175)
> at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:142)
> at
> io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:183)
> at
> io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:38)
> at
> io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:84)
> ... 30 more
> Caused by: java.io.IOException: Too many open files
> at java.base/sun.nio.ch.EPoll.create(Native Method)
> at java.base/sun.nio.ch.EPollSelectorImpl.<init>(Unknown Source)
> at java.base/sun.nio.ch.EPollSelectorProvider.openSelector(Unknown Source)
> at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:173)
>
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