Hi Tim,
I'm writing back again to talk about this issue more.
Per our prior conversation, we've confirmed that, with Artemis (not
ActiveMQ) for Shared Consumers, using a single connection and setting the
nms.clientId parameter in the URI, any Shared Consumer created after the
first one throws an exception ("The key already existed in the
dictionary"). This same exception is thrown under the same circumstances
when the Client ID is not on the URI and is instead generated by the
library.
And anyway, even if it would let us, using a single connection would not
work for us. This is because we have several services that subscribe to a
topic. One of the services takes a bit of time to process the messages from
the topic. For this particular service, we want to scale out to distribute
the message workload. And, technically, we want this ability for each
service. Also, using a queue for this service is not ideal as it defeats
the purpose of having a topic.
Also, in our examination, the Client ID does not appear to be a shared
namespace, per se, as discussed earlier. Or, to clarify further, if the
Client ID is not assigned to the connections via nms.clientId, the
library-generated Client IDs are unique for each Shared Consumer's
connection and have the following format: "ID:HOSTNAME:UUID:N", where UUID
is unique for each connection.
This is odd regarding the earlier discussion, since the generated Client
IDs are unique. Why would our unique Client ID via nms.clientId be treated
any differently?
Nevertheless, as far as we can tell, the only way Shared Consumers work
correctly is without setting our own Client IDs. But it would be
advantageous for us to use our own Client IDs, and it seems we should be
able to do so. And if so, we are back to the idea that this is a bug.
Please let me know what your thoughts are.
Thanks
John
On Tue, Mar 10, 2026 at 9:48 PM John <[email protected]> wrote:
> Thank you for the explanation. I better understand now. And I think
> switching to regular consumers will probably work.
>
> Thanks again.
>
> On Tue, Mar 10, 2026 at 7:53 PM Timothy Bish <[email protected]> wrote:
>
>> On 3/10/26 21:29, John wrote:
>> > Yes, you are correct. I've confirmed that we are using Artemis for the
>> > subscriptions. ActiveMQ is being used for other purposes. The exception
>> > from earlier was when using Artemis.
>> >
>> > So to me, this means it's a bug. If the Client IDs are the same, an
>> > exception is thrown when Artemis is used as the broker. Would the
>> > developers be interested in looking into this? If so, how should we
>> submit
>> > the issue to them?
>> >
>> > Thanks
>>
>> Sorry I was unclear earlier as I was in a rush and I misled you a bit.
>>
>> A JMS client if setting a client ID must give a unique ID which is why
>> you got the error shown as your clients are all trying to connect with
>> the same client ID. This is the issue though that prevents you from
>> using shared subscriptions in they way you want since if you set client
>> IDs the shared subscriptions cannot be shared across connections, only
>> from consumers created by sessions under the same connection. Think of
>> the client ID as a namespace and the lack of one as a global namespace.
>> Shared subscriptions will work for you if your clients do not set a
>> client ID as you've seen because the namespace of all shared
>> subscriptions without a client ID is shared as a global namespace for
>> that subscription across connections. Once you set a client ID you are
>> effectively in a private namespace owned by the connection that set that
>> ID and no two connections can share the same client ID.
>>
>> ActiveMQ does not implement shared subscriptions at all so if you try to
>> use those APIs from the NMS client against that broker the result will
>> likely be an error response or something not doing what you want so you
>> need to use Apache Artemis if you want shared subscriptions but you will
>> need to stick to no client ID if you want to share across connections.
>> Likely you can accomplish what you want by simply moving to using a
>> Queue as consumers on a Queue all compete for messages (work sharing)
>> which seems like what you are going for. but your exact requirements
>> wasn't fully clear so you'd need to provide more info on why you want to
>> use shared subs.
>>
>>
>> >
>> > On Tue, Mar 10, 2026 at 5:33 PM Timothy Bish <[email protected]>
>> wrote:
>> >
>> >> On 3/10/26 20:15, John wrote:
>> >>> Thank you for your reply.
>> >>>
>> >>> If I understand correctly, we should use the same client ID for each
>> >>> client. And, if that is the case, then this has already been tried,
>> >>> and the result is that every client after the first throws this
>> >>> exception:
>> >> I know that ActiveMQ doesn't support shared subscriptions of any sort
>> so
>> >> if you tried this with ActiveMQ you will not get anything to work, and
>> >> if it did somehow create a subscription it would not be a valid one.
>> >> You would need to use Apache Artemis for shared subscription support as
>> >> that has full support for the AMQP JMS mapping. As the specification
>> >> states the subscription is named by the subscription name and the
>> client
>> >> ID so if you want to share your clients either need no client ID or
>> they
>> >> all need the same for the subscription in question.
>> >>
>> >>
>> >>> Unhandled exception. Apache.NMS.NMSException: , ErrorInfo = {
>> >>> key: invalid-field, value: container-id;
>> >>> }
>> >>> ---> Apache.NMS.AMQP.Util.NMSProviderError: amqp:invalid-field
>> >>> at Apache.NMS.AMQP.Util.ExceptionSupport.GetException(Error
>> >>> amqpErr, String message, Exception e)
>> >>> at
>> Apache.NMS.AMQP.Provider.Amqp.AmqpConnection.OnClosed(IAmqpObject
>> >>> sender, Error error)
>> >>> at Amqp.AmqpObject.NotifyClosed(Error error)
>> >>> at Amqp.Connection.OnEnded(Error error)
>> >>> at Amqp.Connection.OnClose(Close close)
>> >>> at Amqp.Connection.OnFrame(ByteBuffer buffer)
>> >>> at Amqp.AsyncPump.PumpAsync(UInt32 maxFrameSize, Func`2 onHeader,
>> >>> Func`2 onBuffer)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.ExecutionContextCallback(Object
>> >>> s)
>> >>> at System.Threading.ExecutionContext.RunInternal(ExecutionContext
>> >>> executionContext, ContextCallback callback, Object state)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread
>> >>> threadPoolThread)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext()
>> >>> at
>> >>
>> System.Runtime.CompilerServices.TaskAwaiter.<>c.<OutputWaitEtwEvents>b__12_0(Action
>> >>> innerContinuation, Task innerTask)
>> >>> at
>> >> System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(Action
>> >>> action, Boolean allowInlining)
>> >>> at System.Threading.Tasks.Task.RunContinuations(Object
>> >> continuationObject)
>> >>> at System.Threading.Tasks.Task`1.TrySetResult(TResult result)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.SetExistingTaskResult(Task`1
>> >>> task, TResult result)
>> >>> at Amqp.AsyncPump.ReceiveBufferAsync(Byte[] buffer, Int32 offset,
>> >>> Int32 count)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.ExecutionContextCallback(Object
>> >>> s)
>> >>> at System.Threading.ExecutionContext.RunInternal(ExecutionContext
>> >>> executionContext, ContextCallback callback, Object state)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread
>> >>> threadPoolThread)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext()
>> >>> at
>> >>
>> System.Runtime.CompilerServices.TaskAwaiter.<>c.<OutputWaitEtwEvents>b__12_0(Action
>> >>> innerContinuation, Task innerTask)
>> >>> at
>> >> System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(Action
>> >>> action, Boolean allowInlining)
>> >>> at System.Threading.Tasks.Task.RunContinuations(Object
>> >> continuationObject)
>> >>> at System.Threading.Tasks.Task`1.TrySetResult(TResult result)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.SetExistingTaskResult(Task`1
>> >>> task, TResult result)
>> >>> at
>> >> Amqp.TcpTransport.TcpSocket.Amqp.IAsyncTransport.ReceiveAsync(Byte[]
>> >>> buffer, Int32 offset, Int32 count)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.ExecutionContextCallback(Object
>> >>> s)
>> >>> at System.Threading.ExecutionContext.RunInternal(ExecutionContext
>> >>> executionContext, ContextCallback callback, Object state)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread
>> >>> threadPoolThread)
>> >>> at
>> >>
>> System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext()
>> >>> at
>> >>
>> System.Runtime.CompilerServices.TaskAwaiter.<>c.<OutputWaitEtwEvents>b__12_0(Action
>> >>> innerContinuation, Task innerTask)
>> >>> at
>> >> System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(Action
>> >>> action, Boolean allowInlining)
>> >>> at System.Threading.Tasks.Task.RunContinuations(Object
>> >> continuationObject)
>> >>> at System.Threading.Tasks.Task`1.TrySetResult(TResult result)
>> >>> at
>> >> System.Threading.Tasks.TaskCompletionSource`1.TrySetResult(TResult
>> result)
>> >>> at Amqp.SocketExtensions.Complete[T](Object sender,
>> >>> SocketAsyncEventArgs args, Boolean throwOnError, T result)
>> >>> at Amqp.TcpTransport.TcpSocket.<>c.<.ctor>b__6_1(Object s,
>> >>> SocketAsyncEventArgs a)
>> >>> at System.Threading.ExecutionContext.RunInternal(ExecutionContext
>> >>> executionContext, ContextCallback callback, Object state)
>> >>> at
>> >> System.Net.Sockets.SocketAsyncEventArgs.<>c.<.cctor>b__174_0(UInt32
>> >>> errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped)
>> >>> at
>> >> System.Threading.PortableThreadPool.IOCompletionPoller.Event.Invoke()
>> >>> at
>> >>
>> System.Threading.ThreadPoolTypedWorkItemQueue.System.Threading.IThreadPoolWorkItem.Execute()
>> >>> at System.Threading.ThreadPoolWorkQueue.Dispatch()
>> >>> at
>> >> System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()
>> >>> at System.Threading.Thread.StartCallback()
>> >>>
>> >>> --- End of inner exception stack trace ---
>> >>> at
>> Apache.NMS.AMQP.NmsConnection.CreateNmsConnectionInternal(Boolean
>> >> sync)
>> >>> at
>> >>
>> Apache.NMS.AMQP.Util.Synchronization.TaskExtensions.AwaitRunContinuationAsync(Task
>> >>> task)
>> >>> at Apache.NMS.AMQP.NmsConnection.StartAsync()
>> >>> at
>> >> Apache.NMS.AMQP.Util.Synchronization.TaskExtensions.GetAsyncResult(Task
>> >>> task)
>> >>> at Apache.NMS.AMQP.NmsConnection.Start()
>> >>>
>> >>>
>> >>>
>> >>>
>> >>> On Tue, Mar 10, 2026 at 4:48 PM Timothy Bish <[email protected]>
>> >> wrote:
>> >>>> On 3/10/26 19:42, John wrote:
>> >>>>> Hi Tim,
>> >>>>>
>> >>>>> Yes, each client has a unique Client ID. And this has been verified.
>> >>>>> However, should the Client ID follow a specific pattern?
>> >>>> That's your problem then, you are creating many uniquely identified
>> >>>> shared subscriptions.
>> >>>>
>> >>>> From the JMS specification
>> >>>>
>> >>>> "A shared non-durable subscription is identified by a name specified
>> by
>> >>>> the client and by the client
>> >>>> identifier if set. If the client identifier was set when the shared
>> >>>> non-durable subscription was first
>> >>>> created then a client which subsequently wishes to create a consumer
>> on
>> >>>> that shared non-durable
>> >>>> subscription must use the same client identifier."
>> >>>>
>> >>>>
>> >>>>> On Tue, Mar 10, 2026 at 4:17 PM Timothy Bish <[email protected]>
>> >> wrote:
>> >>>>>> On 3/10/26 18:51, John wrote:
>> >>>>>>> Hi,
>> >>>>>>>
>> >>>>>>> I have stumbled across an issue that I believe is with
>> >> Apache.NMS.AMQP
>> >>>>>>> library. I'm using the latest stable version, 2.4.0, for my .NET
>> C#
>> >>>>>> service
>> >>>>>>> for message handling, with the latest Apache Artemis and Apache
>> >> ActiveMQ
>> >>>>>>> message brokers.
>> >>>>>>> Both the web page on Uri Configuration (
>> >>>>>>>
>> >>
>> https://activemq.apache.org/components/nms/providers/amqp/uri-configuration
>> >>>>>> )
>> >>>>>>> and the GitHub project (
>> >>>>>>>
>> >>
>> https://github.com/apache/activemq-nms-amqp/blob/main/docs/configuration.md
>> >>>>>> )
>> >>>>>>> state that "nms.clientId" should be used in the Connection Uri to
>> >>>>>> configure
>> >>>>>>> the Client ID.
>> >>>>>>> However, I have found that using "nms.clientId" breaks consumer
>> >>>>>>> functionality for Shared Consumers, who will then receive every
>> >> message
>> >>>>>> in
>> >>>>>>> the topic. And that, excluding the query parameter, allows Shared
>> >>>>>> Consumers
>> >>>>>>> to function correctly, with each consumer receiving only their
>> share
>> >> of
>> >>>>>> the
>> >>>>>>> messages.
>> >>>>>>> Please also note that if one does not include the parameter in the
>> >> Uri
>> >>>>>> but
>> >>>>>>> instead sets the ClientId on the connection object itself, the
>> Shared
>> >>>>>>> Customer will still not function correctly, having the same issue
>> as
>> >>>>>> using
>> >>>>>>> the parameter in the Uri.
>> >>>>>>> However, by not including the nms.clientId parameter, a Client ID
>> is
>> >>>>>>> automatically generated, which I guess is why it works correctly.
>> >>>>>>> Nevertheless, it is less than ideal not being able to use my own
>> >> Client
>> >>>>>> ID.
>> >>>>>>> But maybe I'm doing something wrong. Here is some simple example
>> code
>> >>>>>> using
>> >>>>>>> the nms.clientId parameter that has the issue:
>> >>>>>>>
>> >>>>>>> static async Task SharedAsync(string clientId, CancellationToken
>> >>>>>>> stoppingToken)
>> >>>>>>> {
>> >>>>>>> string uri =
>> >>>>>>>
>> >>
>> $"amqp://localhost:61616?nms.username=artemis&nms.password=artemis&nms.clientId={clientId}";
>> >>>>>> Are you giving each client the same ID or are they each being
>> assigned
>> >>>>>> there own unique client ID ?
>> >>>>>>
>> >>>>>>
>> >>>>>>> var connecturi = new Uri(uri);
>> >>>>>>> var factory = new NMSConnectionFactory(connecturi);
>> >>>>>>> using IConnection connection = await
>> >>>>>> factory.CreateConnectionAsync();
>> >>>>>>> connection.Start();
>> >>>>>>> using ISession session = await
>> >> connection.CreateSessionAsync();
>> >>>>>>> ITopic destination = await
>> >> session.GetTopicAsync("topic-name");
>> >>>>>>> using var consumer = await
>> >>>>>>> session.CreateSharedConsumerAsync(destination, "sub-name");
>> >>>>>>> while (!stoppingToken.IsCancellationRequested)
>> >>>>>>> {
>> >>>>>>> var msg = await
>> >>>>>>> consumer.ReceiveAsync(TimeSpan.FromMicroseconds(250)) as
>> >> ITextMessage;
>> >>>>>>> if (msg is not null)
>> >>>>>>> {
>> >>>>>>> // process message
>> >>>>>>> }
>> >>>>>>> }
>> >>>>>>> }
>> >>>>>>>
>> >>>>>>>
>> >>>>>>> Thanks,
>> >>>>>>> John
>> >>>>>>>
>> >>>>>> --
>> >>>>>> Tim Bish
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> ---------------------------------------------------------------------
>> >>>>>> To unsubscribe, e-mail: [email protected]
>> >>>>>> For additional commands, e-mail: [email protected]
>> >>>>>> For further information, visit:
>> https://activemq.apache.org/contact
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>> --
>> >>>> Tim Bish
>> >>>>
>> >>>>
>> >>>> ---------------------------------------------------------------------
>> >>>> To unsubscribe, e-mail: [email protected]
>> >>>> For additional commands, e-mail: [email protected]
>> >>>> For further information, visit: https://activemq.apache.org/contact
>> >>>>
>> >>>>
>> >>> ---------------------------------------------------------------------
>> >>> To unsubscribe, e-mail: [email protected]
>> >>> For additional commands, e-mail: [email protected]
>> >>> For further information, visit: https://activemq.apache.org/contact
>> >>>
>> >>>
>> >> --
>> >> Tim Bish
>> >>
>> >>
>> >> ---------------------------------------------------------------------
>> >> To unsubscribe, e-mail: [email protected]
>> >> For additional commands, e-mail: [email protected]
>> >> For further information, visit: https://activemq.apache.org/contact
>> >>
>> >>
>> >>
>>
>> --
>> Tim Bish
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: [email protected]
>> For additional commands, e-mail: [email protected]
>> For further information, visit: https://activemq.apache.org/contact
>>
>>
>>
