SAP receive adapter high availability - biztalk

We are having a active-active BizTalk cluster with windows server as software load balancer. The solution includes a SAP receive adapter accepting inbound rfc calls. The goal is to make SAP adapter high availabile.
Read the documentation (), it does says 'You must always cluster the SAP receive adapter to accommodate a two-phase commit scenario.' and 'hosts running the receive handlers for FTP, MSMQ, POP3, SQL, and SAP require a clustering mechanism to provide high availability.'
What we currently did in both the active-active node for BizTalk, we have a host instance enabled. With refering to above documentation, does it mean we did it incorrectly? We should take the clustered host instance instead the active-active deployment?
thanks for all the help in advance.

You need to cluster the host that handles the SAP receive. What this means is that you will always have only one instance of the adapter running at any given time and if one of the server goes down, the other will pick up.
Compare this with your scenario where you simply have two (non-clustered) instances running concurrently: yes, this gives you high availability - but also deadlocks! The two will run independently of each other... With the cluster scenario above, they will run one at the time
To cluster the SAP receive host: open the admin console, find the host, right-click and Cluster.

Related

Is it possible to have 2 BizTalk Server nodes running off of a single MessageBox?

Myself and my colleagues are currently in the process of upgrading our BizTalk environment to BT 2020 from BT 2013R2 and as part of this we are intending on setting up two BizTalk servers so that we can have host instances running across both of them. We do not, however, need more than one MessageBox DB based on the load we see, and after looking online, there doesn't seem to be a breadth of information.
Is it possible to have our BT setup to have 2 servers running off of a single MessageBox and is it complicated to configure?
It’s the basic feature of BizTalk to have multi servers group connected to same message box. On your second computer, when you configure BizTalk using BizTalk Configuration Wizard, you choose option to join existing group and you should select your existing dbs to join.
Microsoft Docs Install BizTalk Server in a Multi-Computer Environment

Some BizTalk Receive Locations are disabled after server reboot

It is found that some BizTalk Receive Locations are disabled after server reboot (BizTalk server and SQL Server are separately installed to different physical servers)
Is there any idea on this scenario? Due to the boot sequence or other issues?
I will assume that, once you enable the receive locations manually, they are working correctly.
Typically, when FILE receive locations fail while pointing to an external server/share, it is because they are no longer available.
Make sure that, during the night, there are no network issues, planned/unplanned downtime of the share (= here your SQL server). A BizTalk receive location will retry to access a share for quite a while before disabling itself. Check the event log(s) for more information. You would want to look for errors/warnings there indicating an issue with connectivity between BizTalk and SQL.
Another issue might be that there are too many connections between your BizTalk server and SQL server. You can provide a maximum number of connections in the FILE share properties.
Also, you could try this link: https://serverfault.com/questions/235032/intermittent-connection-to-windows-7-shared-folder-from-windows-xp-workstations
It describes a potential fix for optimizing throughput for file sharing, although it depends on your operating system.

Biztalk: Is it possible to have multiple hosts that each host can perform its own sending, receiving and processing function?

By reading documents on MSDN, I realized that it is recommended to create separate hosts by functionality (Sending hosts, Receiving hosts and Processing hosts). And if there is only one host in this bizTalk server, this host can perform all receiving, sending, and processing messages functionality.
My question is: Is it possible to have multiple hosts that each host can perform its own sending, receiving and processing function , and not affect each other?
This is for multiple developers working on the same project, because our current situation doesn't allow us to have a full set of SQL Server Database and SQL server for each developer or using VM.
Thanks a lot!
Multiple hosts is not a solution for letting multiple developers work on a single server. A single send/receive adapter can only be assigned to one host.
You will also run into other problems, as all the configuration settings are shared in a single database, a change from 1 developer will effect the others.
This same question was asked and answered at MSDN. What you are trying to do is not supported and will not work. There is no way around this.
You must deploy the same application code to each computer in a BizTalk Group.
Sharing a BizTalk computer for development work is not a workable or productive solution and will have a definite negative affect on productivity.
You are correct, the best way to handle DEV is a VM with the entire stack. This is the issue you must address in your environment.

How to set up a BizTalk active/active cluster

I am setting up a virtual environment as a proof of concept with the following architecture:
2 node web farm
2 node SQL active/passive fail-over cluster
2 node BizTalk active/active cluster
The first two are straight forward, now I'm wondering about the BizTalk cluster.
If I followed the same model as setting up SQL (by using the Fail-over cluster manager in windows to create a cluster) I think I would end up with an active/passive cluster.
What makes a BizTalk cluster Active/Active?
Do I need to create a windows cluster first, or do I just install BizTalk on both machines and configure BizTalk appropriately?
Yes, my understanding is that you do need to cluster the OS first.
That said, you can usually avoid the need for clustering unless you need to cluster one of the 'pull' receive handlers like FTP, MSMQ, SAP etc. For everything else IMO it usually makes sense just to add multiple BizTalk servers in a group, and then use NLB for e.g. WCF Receive adapters.
The Rationale is that by running multiple host instances of each 'type' (e.g. 2+ Receive, 2+ Process, 2+ Send, etc), is that you also have the ability to stop and start host instances without any downtime, e.g. for maintenance (patches), application deployment, etc.
The one caveat with the Group approach is that SSO master doesn't failover automatically, although this isn't usually a problem as the other servers will still be able to work from cache.
You can configure a BizTalk Group in multi-computer environment. You can refer to the doc available at MSDN download center for more details. The document specifically has a section titled "Considerations for clustering BizTalk Server in a Multiple Server environment"
You can also additionally configure your BizTalk host as a clustered resource. You can refer to the documentation available at MSDN for more details.

Are there any open standards for server failover?

I'm building a client-server application and I am looking at adding failover to the client so that when a server is down it will try to connect to another available server. Are there any standards or specifications covering server failover? I'd rather adopt an existing standard than implement my own mechanism.
I don't there is, or needs to be any. It's pretty straight forward and all depends on how you can connect to your sever, but basically you need to keep sending pings/keepalives/heartbeats whatever you want to call em, and when a fail occurs (or n fails in a row, if you want) change a switch in your config.
Typically, the above would be running as a separate service on the client machine. Altenativly, you could create a method execution handler which handles thr execution of all server calls you make, and on Communication failure, in your 'catch' block, flick your switch in config
You're question is very general. here are some general answers:
Google for Fault Tolerant Computing
Google for High Availability Solutions
This is usually handled at either the load balancer or the server level. This isn't something you normally do in code at the client.
Typically, you multihome the servers each having their own IP + one that is shared between all of them. Further, they communicate with each other over tcp for the heartbeat to know which is the Active node in an Active / Passive cluster.
I can't tell what type of servers you have, but most of the windows servers can do this natively.
You might consider asking the question at serverfault to see how to properly configure your servers to support this.

Resources