Creating new PLC4X S7 Basic adapter is working only once

[DerSalm]

Apache StreamPipes version

dev (current development state)

Affected StreamPipes components

Connect

What happened?

The creation of an new adapter (PLC4X S7 Basic) is working only once at the first try.

How to reproduce?

If all the parameters and the Tags are configured correctly, the preview for the "Configure fields" dialog is working. If the Adapter is then created and started, everything is fine. If the "Back" button is activated to get back to "Settings" or if a new adapter is going to be created, the error message "Could not read plc" is shown wehn you return to "Configure fields". The only way to create a new adapter, or edit the existing one is to delete the existing ones and restart the Streampipes.

Expected behavior

New adapters, should be createable and existing ones should be editable.

Additional technical information

It seems, that the connection of the first try is kept open and a new connection could not be established.

Are you willing to submit a PR?

None

[dominikriemer]

Hi @DerSalm thanks for reporting this issue, which I can reproduce. We'll be working on a fix and prepare a patch release 0.95.1 asap.

[dominikriemer]

Hi @DerSalm that's really strange..when I tried to reproduce the error with an actively running adapter and then by navigating to edit -> guess schema, I got the same error than you.
But then I tried it again and it seems that the error only sometimes occurs. E.g., when clicking the refresh button in the schema editor, I sometimes get the Could not read PLC error and (sometimes after 3-5 times), everything works again.
Can you confirm this behaviour?

The logs show the error below which seems to be somehow related to apache/plc4x#1593 with a similar error message below.
@ottlukas @chrisdutz do you have any idea?

PR #2946 contains the latest code after I made some improvements but still has the same issue - the problem occurs in the OneTimePlcRequestReader class.

2024-06-18T23:33:57.113+02:00  WARN 56540 --- [ntLoopGroup-8-1] i.n.channel.embedded.EmbeddedChannel     : More than one exception was raised. Will report only the first one and log others.

io.netty.handler.codec.DecoderException: io.netty.handler.codec.EncoderException: MessageToMessageCodec$1 must produce at least one message.
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:98)
	at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
	at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296)
	at io.netty.handler.codec.ByteToMessageCodec.channelRead(ByteToMessageCodec.java:103)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.logging.LoggingHandler.channelRead(LoggingHandler.java:280)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at org.apache.plc4x.java.s7.readwrite.protocol.S7HMuxImpl.decode(S7HMuxImpl.java:145)
	at org.apache.plc4x.java.s7.readwrite.protocol.S7HMuxImpl.decode(S7HMuxImpl.java:1)
	at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81)
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88)
	at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:722)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:658)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:584)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: io.netty.handler.codec.EncoderException: MessageToMessageCodec$1 must produce at least one message.
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:96)
	at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702)
	at io.netty.handler.logging.LoggingHandler.write(LoggingHandler.java:288)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702)
	at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:113)
	at io.netty.handler.codec.ByteToMessageCodec.write(ByteToMessageCodec.java:108)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702)
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:110)
	at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702)
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:110)
	at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:764)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:790)
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:758)
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:808)
	at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1025)
	at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:306)
	at org.apache.plc4x.java.spi.internal.DefaultConversationContext.sendToWire(DefaultConversationContext.java:70)
	at org.apache.plc4x.java.spi.internal.DefaultSendRequestContext.handle(DefaultSendRequestContext.java:107)
	at org.apache.plc4x.java.spi.internal.DefaultSendRequestContext.handle(DefaultSendRequestContext.java:1)
	at org.apache.plc4x.java.s7.readwrite.protocol.S7ProtocolLogic.lambda$8(S7ProtocolLogic.java:231)
	at java.base/java.util.function.Consumer.lambda$andThen$0(Consumer.java:65)
	at org.apache.plc4x.java.spi.Plc4xNettyWrapper.decode(Plc4xNettyWrapper.java:183)
	at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81)
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88)
	... 40 common frames omitted

[chrisdutz]

Well.. I can't reproduce the error, so it's hard for me who work on it. Especially that I currently only have 4h per week to work on plc4x issues.

[dominikriemer]

This should be fixed now using the CachedPlcConnectionManager.
We'll do some more testing and merge the PR soon.

[chrisdutz]

Oh ... using that is always a good idea ;-)

[DerSalm]

Thanks for the quick help. Sorry that I didn't answer. I was out of the office for one day.