unexpected exception map OPCODE and 'connection closed' issues

[lbarthelemy]

Seen on m2m.eclipse.org:

[NioProcessor-1] INFO m3da.server.tcp.M3daTcpServer - RECEIVED: HeapBuffer[pos=0 lim=985 cap=2048: 6F 72 20 6D 73 67 62 DB D9 8C 0F 73 6F 6D 65 20...]
[pool-3-thread-2] INFO m3da.server.tcp.Handler - client communication identifier : 012345678901234
[pool-3-thread-2] ERROR m3da.server.tcp.Handler - unexpected exception :
m3da.codec.DecoderException: this is not a map OPCODE : 98
        at m3da.codec.impl.BysantDecoderImpl.decodeMap(BysantDecoderImpl.java:563)
        at m3da.codec.impl.BysantDecoderImpl.decodeAwt(BysantDecoderImpl.java:646)
        at m3da.codec.impl.BysantDecoderImpl.decodeOne(BysantDecoderImpl.java:224)
        at m3da.codec.impl.BysantDecoderImpl.decodeAndAccumulate(BysantDecoderImpl.java:127)
        at m3da.codec.impl.BysantDecoderImpl.decodeAndAccumulate(BysantDecoderImpl.java:75)
        at m3da.server.tcp.Handler.messageReceived(Handler.java:88)
        at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:690)
        at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:417)
        at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:47)
        at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:765)
        at org.apache.mina.core.filterchain.IoFilterEvent.fire(IoFilterEvent.java:74)
        at org.apache.mina.core.session.IoEvent.run(IoEvent.java:63)
        at org.apache.mina.filter.executor.OrderedThreadPoolExecutor$Worker.runTask(OrderedThreadPoolExecutor.java:769)
        at org.apache.mina.filter.executor.OrderedThreadPoolExecutor$Worker.runTasks(OrderedThreadPoolExecutor.java:761)
        at org.apache.mina.filter.executor.OrderedThreadPoolExecutor$Worker.run(OrderedThreadPoolExecutor.java:703)
        at java.lang.Thread.run(Thread.java:662)
[NioProcessor-1] INFO m3da.server.tcp.M3daTcpServer - CLOSED

What is the source of this issue? (m3da client is sending bad data?)
What are the possible consequences of this?

On the m3da client (mihini agent) we are encountering "connection closed" traces, can it be linked?

[jvermillard]

looks like the server cannot decode the received bysant stream. You know the content of the message ? I was ciphered ?

[lbarthelemy]

Knowning the content of the message could be quite hard for now: I don't have easy access to server logs on m2m.eclipse.org, and this is the 'result' of running mihini agent automated test suites, so there are several messages sent in a few seconds/minutes.
The connection was not ciphered (I didn't know this M3DA server impl supported ciphering)