Hello Robbie (and All),

Many thanks for the post.

I am aware that HornetQ has issues w.r.t. ttl and so on. However, I thought I 
could send it an empty frame on a regular basis and this would keep the 
connection alive despite this -- perhaps I was mistaken?

I have now tested the connection-ttl-override in Artemis and it works as 
expected. Unfortunately Artemis is not an option at present... and 
connection-ttl-override in HornetQ does not work.

> It might be possible to tinker via reflection to trick it into thinking it 
> should be.

Thank you for the suggestion -- I will look in to this.

> You also mention sending an empty frame, can you elaborate more on what you 
> are doing exactly?

Yes, I can. Incidentally, I modified handleFrame() to be public at present 
(clearly not a long term solution). Then, on connection init 
I have the following code:

transport = Proton.transport();
transport.bind(connection);
transport.setIdleTimeout(0);

Open open = new Open();
open.setIdleTimeOut(new UnsignedInteger(0));
TransportFrame openFrame = new TransportFrame(0, open, null);
 ((TransportImpl) transport).handleFrame(openFrame);

[plus a Task t = event.getReactor().schedule(10000, this); to schedule a 
regular event ]

Then in onTimerTask() I have the following:

byte[] emptyFrame = (new AmqpFramer()).createEmptyFrame(0);
 ((TransportImpl) transport).input(emptyFrame, 0, emptyFrame.length);
Task t = e.getReactor().schedule(10000, this);

I have experimented with various timeout values but none have achieve the 
desired result so far.

> If you look at the protocol trace (environment variable PN_TRACE_FRM=true) do 
> you actually see it sending anything?

Yes, at present I get a number of [[596512129:0] <- Empty Frame] messages -- 
however, when I do the same thing with Artemis I get Empty Frames going in both 
directions, so I suspect HornetQ is not responding correctly.

Thank you & regards,
Matthew


-----Original Message-----
From: Robbie Gemmell [mailto:[email protected]] 
Sent: 07 April 2016 13:14
To: [email protected]
Subject: Re: Reactor Heartbeat [was: RE: Rapid generation of IOExceptions on 
Proton-J client recv() when HornetQ stopped/becomes unavailable]

Hi Matthew,

I think your initial issue here is likely that HornetQ is neither requesting 
clients send it heartbeats, or supporting sending heartbeats to them if it so 
requested. It is however separately enforcing a timeout in its IO layer. I say 
that based on the heartbeat handling only quite recently being fixed in 
ActiveMQ Artemis, which is based on the previously donated HornetQ codebase.

In AMQP 1.0 each side announces their own independent timeout requirements to 
the other side, with each then doing what they need to satisfy the peers 
requirements, either through normal messaging activity or by explicit 
heartbeat/empty frames in its absense. The proton engine satisfies/enforces 
these requirements via the transport tick method, as it seems you might be 
aware, which checks that requested heartbeats have been received and required 
heartbeats get sent, returning when it next needs to be called to keep on top 
of that.

The reactor takes care of calling tick itself as far as I am aware and that 
being the case you also calling it should have no real effect on overall 
behaviour, which seems to be what you observed. In any case, if the broker has 
indeed not advertised an idleTimeout, the tick() will not produce 
heartbeat/empty frames because it has effectively been told it doesn't need to. 
It might be possible to tinker via reflection to trick it into thinking it 
should be.

You also mention sending an empty frame, can you elaborate more on what you are 
doing exactly? If you look at the protocol trace (envieonment variable 
PN_TRACE_FRM=true) do you actually see it sending anything? The heartbeating 
stuff is all hidden behind tick(), so are you achieving that via reflection?

Robbie

On 6 April 2016 at 10:20, Matthew Karlsen <[email protected]> wrote:
> Hello All,
>
> After being directed towards the Proton-J reactor (away from the messenger), 
> I have been experimenting with reactor. I modified the supplied reactor 
> examples to send/recv to/from a queue on HornetQ fairly quickly.
>
> However, I appear to be having less success implementing a 
> heartbeat/keep-alive (HornetQ 2.4.0 will disconnect after a one minute 
> default if it does not receive data from the client).
>
> I have scheduled a regular event using [ e.getReactor().schedule(10000, 
> this); ] with a view to implementing a heartbeat. I then override 
> onTimerTask() and call tick() or send an empty frame within onTimerTask() 
> then re-schedule another call of onTimerTask() -- I have tried several 
> permutations.
>
> However, whether I use tick(), or send an empty frame, it does not seem to 
> maintain the connection.
>
> I was wondering:
> 1) Are there any better approaches?
> 2) What is the "correct" approach/location for using tick()?
>
> Thank you & regards,
> Matthew
>
>
>
> -----Original Message-----
> From: Robbie Gemmell [mailto:[email protected]]
> Sent: 18 March 2016 17:59
> To: [email protected]
> Subject: Re: Rapid generation of IOExceptions on Proton-J client 
> recv() when HornetQ stopped/becomes unavailable
>
> On 18 March 2016 at 12:15, Matthew Karlsen <[email protected]> wrote:
>> Hello All,
>>
>> We have a queue running in HornetQ 2.4.0 (embedded within Wildfly), with a 
>> Proton-J 0.12.0 client periodically connecting to this queue.
>>
>> If HornetQ stops or becomes unavailable when the Proton-J client is running, 
>> the Proton-J client continually generates exceptions similar to that below 
>> (very rapidly).
>>
>> The issue is that the IOException generated exception is handled in 
>> MessengerImpl's processActive() by generating an "Error processing 
>> connection" message in the logs, rather than recv() throwing an exception 
>> and hence the higher level program logic is unable to react to the problem.
>>
>> Is this a bug or am I missing something important?
>>
>> Thank you,
>> Matthew
>>
>> java.io.IOException: An existing connection was forcibly closed by the 
>> remote host
>>         at sun.nio.ch.SocketDispatcher.read0(Native Method)
>>         at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
>>         at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
>>         at sun.nio.ch.IOUtil.read(IOUtil.java:197)
>>         at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
>>         at 
>> org.apache.qpid.proton.driver.impl.ConnectorImpl.read(ConnectorImpl.java:129)
>>         at 
>> org.apache.qpid.proton.driver.impl.ConnectorImpl.process(ConnectorImpl.java:94)
>>         at 
>> org.apache.qpid.proton.messenger.impl.MessengerImpl.processActive(MessengerImpl.java:738)
>>         at 
>> org.apache.qpid.proton.messenger.impl.MessengerImpl.waitUntil(MessengerImpl.java:895)
>>         at 
>> org.apache.qpid.proton.messenger.impl.MessengerImpl.waitUntil(MessengerImpl.java:844)
>>         at 
>> org.apache.qpid.proton.messenger.impl.MessengerImpl.recv(MessengerImpl.java:446)
>>         at 
>> org.apache.qpid.proton.messenger.impl.MessengerImpl.recv(MessengerImpl.java:451)
>>         ...
>>         at java.lang.Thread.run(Thread.java:745)
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: [email protected] For 
>> additional commands, e-mail: [email protected]
>>
>
> Hi Matthew,
>
> It certainly doesnt seem desirable, I'd guess its a bug, though someone 
> actually familiar with Messenger could certainly correct me on that.
>
> Messenger isn't widely used on the proton-j side, and in general Messenger 
> isn't getting much developer attention these days (arguably never did in 
> proton-j, which is mostly still used as an pure protocol engine as intended 
> at the outset) since folks are concentrated more on newer reactive APIs.
>
> Proton-J is a bit behind the curve in terms of the higher level reactive work 
> being/already done in some of the other lanaguages (something I'll be looking 
> to get to), but there was a Java port done of the 'reactor' that exists in 
> proton-c and some of its bindings. I'm not particularly familiar with it 
> either, or how it would handle this situation, but it may be worth you 
> looking at as alternative to Messenger. You can see some example of it in the 
> examples/java/reactor dir, e.g. the Send class (the Recv class in this case 
> is actually a server/listener that accepts incoming connections, such as 
> those made by Send).
>
> Robbie
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [email protected] For 
> additional commands, e-mail: [email protected]
>

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected] For additional 
commands, e-mail: [email protected]

Reply via email to