I am new to Axon and have written a sample code wherein we have an inventory service which is used for adding new inventory, updating inventory and we want to send events to Product Service for any update. Product service should act as a read replica to Inventory Service.
Inventory Service code:
So I created Inventory Aggregate which various command handlers.
Inventory Controller responsible for sending commands
In product Service, I added event handlers
Problem i am facing currently is, when i add a new inventory, it gets reflected in product service db but when i try to do update, it gives me an exception:
Command 'com.example.demo.command.UpdateInventoryCommand' resulted in org.axonframework.commandhandling.CommandExecutionException(The aggregate was not found in the event store)
org.axonframework.axonserver.connector.command.AxonServerRemoteCommandHandlingException: An exception was thrown by the remote message handling component: The aggregate was not found in the event store
When i try to make one more insert into inventory, Inventory Service throws Exception saying:
: "OUT_OF_RANGE: [AXONIQ-2000] Invalid sequence number 0 for aggregate 0, expected 1", An exception was thrown by the remote message handling component: OUT_OF_RANGE: [AXONIQ-2000] Invalid sequence number 0 for aggregate 0, expected 1 Caused by OUT_OF_RANGE: [AXONIQ-2000] Invalid sequence number 0 for aggregate 0, expected 1
Any help would be really appreciated.
Complete code available at :
https://github.com/jahanvibansal/Axon-ProductService
https://github.com/jahanvibansal/Axon-InventoryOrderService
. I realized we need to specify axon.eventhandling.processors.name.mode=tracking property in spring boot application which got it working. I understand there are 2 modes tracking and publish subscribe. I would read more about it.
Related
I am working on Spring Kafka implementation and my use case is consume messages from Kafka topic as batch (using batch listener). when I consumer the list of messages, will iterate and call the REST endpoint for message enrichment. In case REST API fails for any runtime exception, I have implemented retry logic using spring retry. I want to stop the container, after the number of retries fails. So planning to use KafkaContainerStoppingErrorHandler to achieve this. Does the KafkaContainerStoppingErrorHandler commits the previous success messages - say if we receive 10 messages, and for message 1,2,3,4, enrichment call is success and for message 5 enrichment API call fails. so when we restart the container, will I get all 10 again or will I receive messages 5- 10?
or is there a way we can achieve above use case? I looked into all types of error handles of Spring kafka and need input on how to achieve above requirement.
You will get them all again.
You can use the DefaultErrorHandler (with a custom recoverer) and throw a BatchListenerFailedException to indicate which record in the batch failed.
The error handler will commit the offsets up to that record and call the recoverer with the failed record; in your custom recoverer you can stop the container (use the same logic as the container stopping error handler).
In versions before 2.8, this same functionality is provided by the RecoveringBatchErrorHandler.
I have been reading This Book on page 58 to understand how to do asynchronous event integration between microservices.
Using RabbitMQ and publish/subscribe patterns facilitates pushing events out to subscribers. However, given microservice architectures and docker usage I expect to have more than once instance of a microservice 'type' running. From what I understand all instances will subscribe to the event and therefore would all receive it.
The book doesn't clearly explain how to ensure only one of the instances handle the request.
I have looked into the duplication section, but that describes a pattern that explains how to deduplicate within a service instance but not necessarily against them...
Each microservice instance would subscribe using something similar to:
public void Subscribe<T, TH>()
where T : IntegrationEvent
where TH : IIntegrationEventHandler<T>
{
var eventName = _subsManager.GetEventKey<T>();
var containsKey = _subsManager.HasSubscriptionsForEvent(eventName);
if (!containsKey)
{
if (!_persistentConnection.IsConnected)
{
_persistentConnection.TryConnect();
}
using (var channel = _persistentConnection.CreateModel())
{
channel.QueueBind(queue: _queueName,
exchange: BROKER_NAME,
routingKey: eventName);
}
}
_subsManager.AddSubscription<T, TH>();
}
I need to understand how a multiple microservice instances of the same 'type' of microservice can deduplicate without loosing the message if the service goes down while processing.
From what I understand all instances will subscribe to the event and
therefore would all receive it.
Only one instance of subscriber will process the message/event. When you have multiple instances of a service running and subscribed to same subscription the first one to pick the message will set the message invisible from the subscription (called visibility timeout). If the service instance is able to process the message in given time it will tell the queue to delete the message and if it's not able to process the message in time , the message will re-appear in queue for any instance to pick it up again.
All standard service bus (rabbitMQ, SQS, Azure Serivce bus etc) provide this feature out of box.
By the way i have read this book and used the above code from eShotContainers and it works the way i described.
You should look into following pattern as well
Competing Consumers pattern
Hope that helps!
We have been seeing the following 'warnings' in the event log of our BizTalk
machine since upgrading to BTS 2006. They seem to occur
randomly 6 or 8 times per day.
Does anyone know what this means and what needs to be done to clear it up?
we have only one BizTalk server which is running on only one machine.
I am new to BizTalk, so I am unable to find how many tracking host instances running for BizTalk server. Also, can you please let me know that we can configure only one instance for one server/machine?
Source: BAM EventBus Service
Event: 5
Warning Details:
Execute batch error. Exception information: TDDS failed to batch execution
of streams. SQLServer: bizprod, Database: BizTalkDTADb.Cannot insert
duplicate key row in object 'dta_MessageFieldValues' with unique index
'IX_MessageFieldValues'.
The statement has been terminated..
I see you got a partial answer in your MSDN Post
go to BizTalk Admin Console ,check in Platform Settings -> Hosts, in the list of hosts on the right, confirm that only a single Host has the Tracking column marked as Yes.
As to your other question. Yes you can run a Single Host Instance on a Single Server. Although when your server starts to come under a bit of load you may want to consider setting up some more so you can balance the workload better.
Say I were to create a promoted property on an HL7 v2 schema. I want to use this promoted property in order to correlate two messages in a parallel convoy. I did a dummy application without using HL7 schemas and all worked just as expected. To sum up what I did, see this tutorial.
It's actually quite simple, which is why I'm wondering there is a catch when it comes to the HL7 schemas.
I created the PropertySchema, Promoted the field I'm after in the HL7 body schema, everything compiled and deployed fine, I ran a query for the subscriptions on my receive ports and they look OK
http://schemas.microsoft.com/BizTalk/2003/system-properties.ReceivePortID == {D2F99A76-E28A-4B3E-AC52-F4E2F92453C3}
And
http://schemas.microsoft.com/BizTalk/2003/system-properties.MessageType == http://microsoft.com/HealthCare/HL7/2X#ORU_ALL_25_GLO_DEF
And
https://myNS.ECGCorrelationPropertySchema.CommonAccessionID Exists
However, I get a
The published message could not be routed because no subscribers were found. This error occurs if the subscribing orchestration or send port has not been enlisted, or if some of the message properties necessary for subscription evaluation have not been promoted.
and looking in the Biztalk Group admin console, when I view the suspended messages, I don't see that the property has been promoted
Edit to add message context
Error Report Context
I have checked and double-checked, the schemas are there, there are duplicate schemas the Event log even shows A message was received of type http://microsoft.com/HealthCare/HL7/2X#ORU_ALL_25_GLO_DEF when I receive a message.
So now, I guess I have 2 questions:
If the promotions were happening successfully, would they show in the Message --> Context dialog (they did in my non-HL7 dummy app)
If they aren't supposed to show, is there a setting/property/anything somewhere I missed that is unique to using HL7v2 schemas?
Short answers:
1. Yes, provided this message came directly from the Receive Pipeline
2. No, once emitted from the disassembler, there is nothing special about an HL7 Message.
Make sure you're looking at the actual Suspended Message and not the Error Report. The best way to check this is to Stop, don't Unenlist, the Orchestration. The Message will then suspend Resumable.
Within my BizTalk 2010 solution I have the following orchestration that’s is started by the receipt of a courier update message. It them makes a couple of call to AX's WCF AIF via two solicit-response ports, a Find request and an Update request.
For this application we are meeting audit requirements through use of the tracking database to store the message body. We are able to link to this from references provided in BAM when we use the TPE. The result for the customer is nice, they get a web portal from which they can view BAM data of message timings etc. but they can also click a link to pull up a copy of the message payloads from the tracking db. Although this works well and makes use of out-of-box functionality for payload storage it has led to relatively complex jobs for the archiving of the tracking db (but that's another story!).
My problem relates to continuation. I have created the following Tracking Profile:
I have associated the first of the orchestration's two solicit response ports with the continuation RcvToOdx based on the interchange Id and this works, I get the following single record written to the Completed activity table:
So, in this case we can assume that an entry was first written on receipt in the inbound message, with the TimeReceivedIntoBts column populated by the physical file receive port. The FindRequestToAx column was then populated by the physical WCF send port. Because this was bound to the RcvToOdx continuation Id and used the same interchange Id and the previously mentioned file receive message, the update was made to the same activity. Notification of the resulting response was also updated to the same activity record - into the FindResponseFromAx column.
My problem is that I would also like BAM to record a timestamp for the subsequent UpdateRequestToAx. Because this request will have the same interchange Id as the previous messages I would expect to be able to solve this problem by simply binding the AxUpdate send port (both send and receive parts of it) to the same continuation id, as seen in the following screen grab:
I also map the UpdateRequestToAx milestone to the physical Ax_TrackAndTraceUpdate_SendPort (Send) and the OrchestrationCompleted milestone to Ax_TrackAndTraceUpdate_SendPort (Receive)
Unfortunately, when I try this I get the following result:
Two problems can be seen from the above db screen grab:
1. Date for the update send port was inserted into a new activity record
2. The record was never completed
I was surprised by this because I'd thought since they update port was enlisted to use the same continuation, and the single InterchangeId was being used by all ports for the continuation Id then all the data milestones would be applied to a single activity.
In looking for a solution to this problem I came across the following post on Stack Overflow suggesting that the continuation must be closed from the BAM API: BAM Continuation issue with TPE. So, I tried this by calling the following method from an expression shape in my orchestration:
public static void EndBAMContinuation(string continuationId)
{
OrchestrationEventStream.EndActivity(CARRIER_ORDER_ACTIVITY_NAME, continuationId);
}
I can be sure the method was called ok because I wrapped the call with a log entry from the CAT framework which I could see in debug view:
I checked the RcvToOdx{867… continuation Id against the non-closed activity and confirmed they matched:
This would suggest that perhaps the request to end the continuation is being processed before the milestone of the received message from the UpdateAx call?
When I query the Relationsips tables I get the following results:
Could anyone please advise why the UpdateToAx activity is not being completed?
I realise that I may be able to solve the problem using only the BAM API but I really want to exhaust any possibility of the TPE being fit for purpose first since the TPE is widely used in other BizTalk solutions of the organisation.
To solve this problem I created a 2nd continuation in the TPE.
"RcvToOdx" continuation for the Find and "OdxToUpdate" continuation for the update - source is InterchangeId on the initial receive port - UPS_TrackAndTrace (same as for other "RcvToOdx" continuation), dest Id is the InterchangeId mapped to update send port.