integrating your business

Yesterday Peter Borremans and Sam Vanhoutte were guest speakers at the BizTalk User Group Sweden in Stockholm.
We presented an overview of Microsoft Host Integration Server, a product that allows you to integrate with resources on IBM Mainframes and Midrange systems. The presentation went smoothly and all the demo's worked :)
It was a great pleasure to present this product to the many interested people who attended the presentation.

The slide deck of our presentation can be found here. (change the file extention to 'pptx' after downloading)
When the presentation is available online, we will post a link on this blog.

 Peter Borremans

Host Integration Server is by default configured to use 'smart multihoming'. When using smart multihoming, the Host Integration Server (HIS) will send all his available IP addresses to the clients. The SNA client will use the address from the list with addresses received from the server that is closest to its own subnet or IP address.

In some scenarios smart multihoming can cause some problems. What if one of the IP addresses received from the HIS server is not reachable (e.g. an IP address that is used to link to a separate network)? In that case the client will try to connect to one of the other address received from the HIS server. This only happens after a delay (default 45 seconds). After the delay the client will connect to the IP address that connects successfully.

This delay when connecting to the server is not a desired behavior.

How do we fix this?

On the client we can disable smart multihoming. To do this, make sure that this registery key 'ReadjustMultihomedAddresses' is set to 'NO'. If the key does not exist, create it. The location of this registry key should be: 'HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Snabase\Parameters\SnaTcp'.

If smart multihoming is disabled on our client, the new behavior is as follows: the client will try to connect to a server IP address in the order as the client received them from the server. Again, this causes problems... What if the IP address that is not reachable appears first in the list? We will again see a long delay when connecting to the server. Luckely we can fix this!

Host integration server uses the network bindings to determine in what order to present its IP addresses to the client. You can find the network binding  on the 'Network Connections' sceen, 'Advanced' menu option, 'Advanced Settings...', then 'Adapters and Bindings' tab. On that tab page, every network connection is listed and we are able to change the order in which they appear. Adapt the order to your needs (reachable IP's first!!!). Host Integration Server will use the order specified here to send it's IP list to the client.

Now that both steps are done (disable smart multihoming AND change the network bindings on the server), the client will no longer experience a delay when connecting to the HIS server.

Peter Borremans 

On 16th March, CODit is speaking at the BizTalk User Group in Stockholm (Sweden).

CODit is presenting an introduction to Host Integration Server, the secret gem of Microsoft :)

You can subscribe here: http://swebug20100316-widget.eventbrite.com/

Content of the presentation:

Session: Introduction to Microsoft Host Integration Server
Speakers: Peter Borremans & Sam Vanhoutte

Over the years, a lot of companies invested in IBM mainframe (zSeries) or midrange (iSeries) systems. The mainframe architecture is not compatible with nowadays standards and architectures. Rewriting applications is not always feasible and desired. These applications are often very large systems with high reliability and performance. If possible
people's skills must be reused. This leads to the need of integrating with existing host systems. Microsoft created Host Integration Server (HIS) to integrate with host systems.
This session will cover all important components of HIS and how Mainframe functionality is exposed to newer technologies:

Network integration

As mentioned earlier, IBM host systems (most of the time mainframe systems) use a proprietary network architecture.
HIS network integration will allow other systems to connect to those networks and expose functionality higher up in the stack (MQ, Applications, Data).

Data integration

HIS data integration will allow Microsoft systems to access data stored in DB2 databases or in VSAM files.
This is either done with by using .NET data providers (DB2 or VSAM) or by using BTS adapters (DB2 or VSAM)

Application integration

HIS application integration will allow Microsoft systems to interface with IBM host applications as CICS transactions (Transaction Integrator) or IMS.
Application integration is without any doubt one of the most powerful features of HIS.

Messaging integration

By using HIS, Microsoft BizTalk server can communicate with MQSeries on any other platform. HIS provides a WebSphere MQSeries client-based adapter. This adapter does not require a MQSeries installation on a Windows Server box. The WebSphere MQSeries client-based adapter allows direct access to MQSeries on host systems.

The following warning is often seen on servers running Microsoft Host Integration Server:

Log Name:      Application
Source:        SNA Base Service
Date:          date
Event ID:      561
Task Category: None
Level:         Warning
Keywords:      Classic
User:          user
Computer:      computer
Description:
Write to mailslot or socket failed, rc = 64

 EXPLANATION

 A Win32 WriteFile() or winsock sendto() call failed. The return code is shown.

 ACTION

 Provide network support personnel with the event log file(s) related to SNA, and the return code included in this message. For information about SNA log files, see the "Microsoft Host Integration Server Online Books.

 The warning is caused because Host Integration Server tries to communicate with all the servers in a subdomain (and the clients) via broadcasts messages. Host Integration Server does this over all protocols that are selected in the SNA Manager. Not all of these protocols are enabled on your network, if one of them is not enabled this warning will pop up.

To fix this warning unselect the protocol that causes the warning as shown in this screenshot.

Typically you enable TCP/IP and you disable Named Pipes. After adapting the configuration the warning disappears.

Peter Borremans