Re: BizTalk Clusters

Thanks for the detailed feedback Tomas. One item that caught my eye was
your suggestion in the link
(http://www.biztalkgurus.com/forums/thread/7887.aspx) that the File adapater
requires clustering to ensure a document does not get pulled twice. I
haven't been able to confirm this in the BizTalk documentation. For
example, there is a help file in the BTS 2006 Help titled "Scaled-Out
Receiving Hosts" at http://msdn2.microsoft.com/en-us/library/aa577415.aspx.
This suggests that FTP requires clustering, but that a File adapter can be
scaled out in a BizTalk Group with no mention of possible issues.

Is MSDN misleading? Or did I misread your comment at the link above?
Thanks again. The specific text from your link is pasted below. Perhaps
you were talking about two BizTalk servers that were not in the same BizTalk
group??

Mark

You wrote:
"1) What Greg was trying to explain was that the File and FTP adapters don't
really "load balance" in that sense. If you put two bts servers to monitor
the same remote folder on a server using the FILE adapter, for example,
you're very likely end up pulling messages twice. Certainly not what you
intended. What's recommended in such an scenario is to cluster the BizTalk
servers so that only one is active at a time (hence only one is actively
polling the remote folder); if that server fails, clustering ensures the
other server picks up, thus achieving high availability."


"Tomas Restrepo [MVP]" <tomasr@xxxxxxxx> wrote in message
news:75004BF3-149D-4ED2-B380-ED3103096542@xxxxxxxxxxxxxxxx
Mark,

This is extremely useful feedback and resonates with our impression. By
"stateful adapaters" I'm assuming you mean the use of FIFO (first in
first out)?

Stateful adapters might not be the best description. Think more in terms
of which receive-side adapters work on protocols that offer/don't offer
other scalability mechanisms. For example, MSMQ doesn't really support
load balancing so if you want to improve reliability and fault tolerance
you have to cluster MSMQ as well as the BizTalk hosts receiving MSMQ
messages. Same with the File or FTP adapters.

However, other protocols don't suffer from this. For example, HTTP and Web
Services lend themselves very well to load balancing, so you can instead
use NLB (Network Load Balancing) to distribute load and improve
availability for your biztalk servers. Part of the confusion might start
here in that some people will call this "clustering" as well, but that's
not entirely correct.

This older thread on the BizTalkGurus forums contains some more detailed
explanations of some of this that might be helpful:
http://www.biztalkgurus.com/forums/thread/7887.aspx

Three other things to keep in mind:

1- BizTalk can support several alternatives at the same time. For example,
you might have some servers clustered and others load balanced. That's
perfectly possible in the BizTalk architecture.

2- The term "BizTalk Group" has nothing to do with clustering. All servers
attached to a single BiztalkMgmtDB database are part of the same BizTalk
Group; it's an organization/management thing, and has nothing to do with
clustering or load balancing at all directly.

3- Notice that if you care about fault tolerance and reliability you
*will* want to cluster you SQL Server hosting the BizTalk system databases
(message box, and so on).


--
Tomas Restrepo
tomasr@xxxxxxxx
http://www.winterdom.com/weblog/



.

Relevant Pages

  • Re: 4 server configuration
    ... already-clustered-Sql hardware for clustering SSO services in a BizTalk ... Two load balanced BizTalk 2006 Servers, ...
    (microsoft.public.biztalk.general)
  • Re: BizTalk Clusters
    ... Think more in terms of which receive-side adapters work on protocols that offer/don't offer other scalability mechanisms. ... MSMQ doesn't really support load balancing so if you want to improve reliability and fault tolerance you have to cluster MSMQ as well as the BizTalk hosts receiving MSMQ messages. ... Part of the confusion might start here in that some people will call this "clustering" as well, ...
    (microsoft.public.biztalk.general)
  • Re: Active/Active/Passive cluster Newb question...
    ... There are no load balancing aspects at all to a Windows cluster. ... But you have to properly plan for the scenarios that may take place during failover. ... If performance is what you are after clustering is not the answer. ... I found out that Active/Active servers are ...
    (microsoft.public.sqlserver.clustering)
  • RE: Fault tolerance advise
    ... We are in the process of implementing Biztalk 2006, ... SQL SERVER 2005 backend, two server cluster, data stored on our EMC ... We have been testing load balancing, and I'm worried that it's not going to ... Does clustering the Biztalk servers do anything for us? ...
    (microsoft.public.biztalk.general)
  • Re: Cluster synchronize
    ... Clustering is also not compatible with Windows Load Balancing, ... Clustering is not a load-balancing technology. ... > Mike Epprecht, Microsoft SQL Server MVP ... >>I have an architecture which has 4 DB servers on the whole; ...
    (microsoft.public.sqlserver.clustering)
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