Hello Robbie,

We are using proton-j client with SSL and many of our customers are hitting 
this issue.
Here are my findings after debugging through this issue:

-          When incoming bytes arrive on the SocketChannel – proton-j client 
gets signaled by nio & as a result it unwinds the transport stack – as a result 
all the TransportInput implementations performs its task on the Read Bytes and 
hands off to the Next Layer in the stack (transport to ssl, ssl to frameparser 

-          While unwinding that stack, SimpleSSLTransportWrapper.unwrapInput 
reads(16k bytes) from _inputBuffer and the result - decoded bytes are written 
to _decodedInputBuffer – as an intermediate buffer.

-          It then flushes bytes from intermediate buffer to the next layer & 
invokes an _underlyingInput.Process() – to signal it that it has bytes in its 
input buffer.

-          If the underlyingInput (lets say FrameParser) buffer size is small – 
lets say 4k – then decodedInputBuffer will be left with 12k bytes & Over time 
this accrues.

The fix here is to flush decodedInputBuffer to the Next transport in the 
Network Stack & call _underlyingInput.Process() - until decodedInputBuffer is 
empty. Here’s the pull request - https://github.com/apache/qpid-proton/pull/73

Pl. let me know if we need to do more to fix this issue comprehensively.


From: Robbie Gemmell<mailto:robbie.gemm...@gmail.com>
Sent: Thursday, March 31, 2016 9:19 AM
To: proton@qpid.apache.org<mailto:proton@qpid.apache.org>
Subject: Re: Proton-j Reactor - Receiver

On 31 March 2016 at 04:32, Garlapati Sreeram Kumar <sreer...@live.com> wrote:
> Hello All!
> I am using Proton-J reactor API (Version 0.12.0) for receiving AMQP Messages 
> (from Microsoft Azure Event Hubs): 
> https://github.com/Azure/azure-event-hubs/blob/master/java/azure-eventhubs/src/main/java/com/microsoft/azure/servicebus/amqp/ReceiveLinkHandler.java#L124
> Am using the onDelivery(Event) callback to receive messages. I really 
> appreciate your help with this issue/behavior:
> ISSUE: I noticed that the last few messages on the Queue are not being issued 
> to onDelivery(Event) callback by the Reactor
> - Then, I went ahead and enabled proton Frame tracing (PN_TRACE_FRM=1) and 
> discovered that the Transfer frames corresponding to those messages were not 
> even delivered to Client. Then, I looked at our Service Proton Frames and can 
> clearly see that they are being delivered by the Service. And other AMQP 
> clients (for ex: .net client can see the Transfer frames)
> - Is this a known behavior?
> Does Reactor code path disable Nagle on underlying socket – could this be 
> related? or is there any other Configuration that we should be setting to see 
> all Transfer frames received on the Socket?
> Please advice.
> Thanks a lot in Advance!
> Sree
> Sent from Mail for Windows 10

I'm not aware of anyone else reporting anything like that. I don't see
anything in the code suggesting the reactor sets TCP_NODELAY trueon
the socket, but I wouldn't think that should matter here.

The frame trace logging is done after the bytes are given to the
Transport and are processed into frames, so a lack of logging could
suggest various things such as they didnt actually get there, they
werent processed, something went wrong before they did/were, something
went wrong decoding them, etc. Its hard to say much more without more


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