BizTalk Adapter Pack – SAP Binding ReceiveTimeout

 

One of the most important configurations to make inside a SAP Receive location is the “receiveTimeout” property.  The documentation describes this property as:

“Specifies the WCF message receive timeout. Essentially, this means the maximum amount of time the adapter waits for an inbound message. The default is 10 minutes.

Important

For inbound operations such as receiving IDOCs, we recommend setting the timeout to the maximum possible value, which is 24.20:31:23.6470000 (24 days). When using the adapter with BizTalk Server, setting the timeout to a large value does not impact the functionality of the adapter.”

The default value(10 minutes), is too short of a period for BizTalk to stop listening for messages from SAP.  For instance, if your organization has a weekly back up scheduled for SAP, it will likely take longer than 10 minutes.  The documentation indicates that there is no impact to using a large number so I am not sure why the default is only 10 minutes.

 

 

Just to give a practical example of what you can expect when SAP goes down (either planned or unplanned) from a BizTalk perspective.

SAP going down

Event Type:        Warning

Event Source:    BizTalk Server 2009

Event Category:                (1)

Event ID:              5740

Date:                     3/13/2XXX

Time:                     10:01:31 PM

User:                     N/A

Computer:          SERVER

Description:

The adapter "WCF-Custom" raised an error message. Details "The WCF service host at address sap://CLIENT=XXX;LANG=EN;@a/SAPServer/00?ListenerGwServ=SAPGateWay00&ListenerGwHost=SAPServer&ListenerProgramId=IDOC&RfcSdkTrace=False&AbapDebug=False has faulted and as a result no more messages can be received on the corresponding receive location. To fix the issue, BizTalk Server will automatically attempt to restart the service host.".

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Event Type:        Warning

Event Source:    BizTalk Server 2009

Event Category:                (1)

Event ID:              5740

Date:                     3/13/2XXX

Time:                     10:01:31 PM

User:                     N/A

Computer:          SERVER

Description:

The adapter "WCF-Custom" raised an error message. Details "Microsoft.Adapters.SAP.RFCException: Details: ErrorCode=RFC_FAILURE. AdapterErrorMessage=An exception has occurred on the listener while executing RfcWaitForRequest..

   at Microsoft.ServiceModel.Channels.Common.Design.AdapterAsyncResult.End()

   at Microsoft.ServiceModel.Channels.Common.Channels.AdapterReplyChannel.EndTryReceiveRequest(IAsyncResult result, RequestContext& requestContext)

   at Microsoft.Adapters.Internal.LayeredChannelBindingElement.LayeredInboundChannel`1.System.ServiceModel.Channels.IReplyChannel.EndTryReceiveRequest(IAsyncResult result, RequestContext& context)

   at System.ServiceModel.Dispatcher.ReplyChannelBinder.EndTryReceive(IAsyncResult result, RequestContext& requestContext)

   at System.ServiceModel.Dispatcher.ErrorHandlingReceiver.EndTryReceive(IAsyncResult result, RequestContext& requestContext)".

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

 

Event Type:        Warning

Event Source:    BizTalk Server 2009

Event Category:                (1)

Event ID:              5740

Date:                     3/13/2XXX

Time:                     10:01:32 PM

User:                     N/A

Computer:          SERVER

Description:

The adapter "WCF-Custom" raised an error message. Details "The faulted WCF service host at address sap://CLIENT=XXX;LANG=EN;@a/SAPServer/00?ListenerGwServ=SAPGateWay00&ListenerGwHost=SAPServer&ListenerProgramId=IDOC&RfcSdkTrace=False&AbapDebug=False could not be restarted, and as a result no messages can be received on the corresponding receive location. BizTalk Server will continue trying to start the service host until it succeeds or the receive location is disabled.

To fix the problem, you may choose to:

1. Use the error information given to fix the problem.

2. Restart the receive location.

3. Keep waiting for BizTalk to recycle the service host. Another event will notify if the service host is successfully started.

SAP coming back up

Event Type:        Information

Event Source:    BizTalk Server 2009

Event Category:                (1)

Event ID:              8112

Date:                     3/13/2XXX

Time:                     11:03:13 PM

User:                     N/A

Computer:          SERVER

Description:

The WCF service host at address sap://CLIENT=XXX;LANG=EN;@a/SAPServer/00?ListenerGwServ=SAPGateWay00&ListenerGwHost=SAPServer&ListenerProgramId=IDOC&RfcSdkTrace=False&AbapDebug=False was successfully restarted, therefore the associated receive location can now receive messages.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

 

You are now able to receive messages from SAP without any intervention.  Had we not set an appropriate ReceiveTimeout, the receive location would have still be down when SAP tried to push this IDoc to our system.

 

You never want your middleware to be the cause of an outage so it is important to understand when your dependant servers/services have scheduled maintenance so that you can ensure that your application can sustain this downtime.  Configuring the ReceiveTimeout to an appropriate value will reduce the chance that BizTalk will be down due to someone else's maintenance window.

BizTalk Adapter Pack 2.0 – SAP Adapter IDoc Schema Versioning Part 2

In my first post, I discussed how the BizTalk Adapter pack Consume Adapter Service wizard tightly couples the IDoc schema version with the version of SAP that you used to generate the schema with.  The goal of this post is to discover how you can avoid this tight coupling and hopefully survive an SAP upgrade.  I know the organization that I work for would not be pleased with having to update all of our IDoc schemas when we do our next SAP Upgrade just because the version of SAP has been incremented.

When the BizTalk Adapter Pack came out I was pretty excited that I could throw away my Flat File schemas and pipelines.  While true, it comes at a cost.  When using the XML Receive pipeline with the new Adapter, the Adapter will use data in the SAP Control record to determine what version of the message you retrieving from SAP and will assign a namespace to your message, that contains SAP version information, before depositing it in the message box. If have not changed your SAP version since generating your IDocs you are in business.  If you have upgraded your SAP system or have generated the wrong schemas for your SAP version then you will be in a lot of pain. 

To get around this tight coupling issue, you can revert back to the old style of IDoc processing which involves flat files and pipelines.  Now there is nothing really wrong with this model, but it does require a few extra steps and is not as “clean” a solution as using the XML Receive pipeline.

I will now take you through how you generate a flat file schema that can be used to process different versions of the same IDoc.  When I say different schemas this means that the version, and therefore namespace, are different but structurally the documents are the same.  Note that I will not go through all steps required to generate an IDoc schema, only those that are important to generate a Flat File schema.  To see a more comprehensive walk through of generating an IDoc schema, please see my Webcast.

 

• When using Consume Adapter Service wizard, ensure that “GenerateFlatFileCompatible” is set to true.

When you set the GenerateFlatFileCompatible property to true, you will now see the flat file specific data within the Schema specification.

Without setting GenerateFlatFileCompatible ,  the schema will not contain this flat file information.

• You also want to indicate the “ReceiveIDocFormat” will be a String.  You will find out why this is important later on in this post.

• Once the schemas have been imported into Visual Studio, enable “Flat File Extensions” to the “core schema”.  When using the BizTalk Adapter Pack Consume Adapter Service wizard you will generate more than 1 schema unlike the old .Net Connector version where you would always only generate 1 schema.  By “core schema” I mean the one that contains the “meat” of your schema, not one that contains the shell(all of the imported schemas) or any of the base type schemas.

• You will now need to create a Receive Pipeline and add a Flat File disassembler

• Add your “shell” schema to the document schema property

• Build and Deploy your application
• When configuring your SAP Receive location you will want to specify your Receive Pipeline as opposed to XML Receive

• On the Binding tab, set the “ReceiveIdocFormat” to String

• On the Messages tab, provide an XPath expression that will extract the flat file data so it can be disassembled by the Receive Pipeline.  The XPath expression that I used is:

  /*[local-name()='ReceiveIdoc']/*[local-name()='idocData']

  The adapter is essentially wrapping this flat file in XML tags so that it can make it through the adapter stack as an XML message. 

  Also ensure the “Node encoding” is set to String as the default is “XML”

• Start your application and you are good to go

 

• Up until this point, I have not modified the namespace of my schema and everything worked well as expected

 

 

• However, the purpose of this post is to demonstrate how we can break away from the default namespaces that are generated by the adapter.

• Since I have redeployed the application, the message subscription have also been updated:

 

• Start your application up and it should function with this new namespace and therefore subscription.

 

• The next test is to generate a different version of an SAP IDoc and ensure receiving a different version of the IDoc does not break our application.  If you recall from Post 1 we received an error in this situation.  From the Consume Adapter Service wizard, I am deliberately going to generate a schema that has a DOCREL  greater than my current SAP version.

• My subscription is updated and is looking for a “710” IDoc where as SAP is going to generate a
  “700” IDoc

• I received, processed and delivered the message downstream without issue

• Even though SAP, populated the Control record with DOCREL = 700, I am able to process this message because this DOCREL is not being used to derive the target namespace like it is when you use the XML Receive pipeline.  This is really where the value of the Flat file pipeline comes in as it will use the namespace in the schema that is configured inside the pipeline instead of having the Adapter generate a namespace automatically.   This also works as the structure of the 700 IDoc has not changed in the 710 IDoc.  If the structure of the IDoc changes with the version number then you have no other option than to regenerate your schemas.

 Gotcha!

So everything is fine and dandy until you try to deploy another IDoc with the same Program Id/Partner Profile.  There is bug with the BizTalk Adapter Pack that prevents you from deploying multiple IDoc Flat File schemas with the same Program ID.  Look for a workaround with my next post in this series.  I should be able to turn that post around quicker than this one.

Off Topic: Canada Wins....Mikael loses

During this past MVP summit there was an abundance of trash talk regarding Olympic Hockey. Mikael Hakanssons and I made a Blog bet with the loser of the bet dedicating a post to the winning country. As I am sure you have heard, Canada beat USA in overtime 3-2 on Sunday. I will give Mikael credit for being a good sport even though he jumped on the USA bandwagon as soon as Sweden was eliminated. You can find his post here.