Jim Johnson's Blog - All Comments

re: MSDTC changes in WS2008, Part 3: Cluster features

jim-johnson — Fri, 09 Jan 2009 16:26:10 GMT

My understanding is that your question was handled offline by the transactions team. In the interest of sharing, here's my quick answers:

First, in order to get the mapping to work, you'll need to use the -tmMappingSet feature, define mappings for both SQL instances. Roughly, the commands will be of the form:

msdtc –tmMappingSet –name MyMapping –service SQL$<xxxx> -clusterResource <cluster resource name>

where SQL$<xxxx> is the SQL service instance for the particular server group.

The only way I know to tell which resource is being used by SQL is to use the MSDTC UI to see which one gets activity when you try a transaction against a particular SQL instance.

Finally, since MSDTC1 is a cluster resource in the SQL1 cluster group, if it fails, the group fails and restarts. So, if SQL1 is running, you should be able to assume MSDTC1 is running as well.

Hope this helps,

Jim.

re: Understanding nested transaction scopes

jim-johnson — Fri, 09 Jan 2009 16:19:39 GMT

In the second example transaction 'b' is created by TransactionScope 't', and committed at the end of that TransactionScope.

TransactionScopes 's' & 'u' operate on transaction 'a', which aborts at the end of TransactionScope 'u'.

Jim.

re: Understanding nested transaction scopes

peter — Fri, 09 Jan 2009 07:36:01 GMT

Hi, the acticle is much helpful. Thanks.

But I am still confused with the second example.

will transaction 'b'(transactionscope 'u') be commited successfully?

re: MSDTC changes in WS2008, Part 3: Cluster features

Uttam Parui — Tue, 06 Jan 2009 23:43:42 GMT

I have a question on mapping a MSDTC resource to SQL Server and was hoping to get some clarification.

Scenario

Windows 2008 cluster

Two SQL Server groups – SQL1 and SQL2

We create two MSDTC resources – MSDTC1 in SQL1 group and MSDTC2 in SQL2 group

Will MSDTC1 be automatically mapped to SQL1 and MSDTC2 mapped to SQL2?

My understanding is that by default, SQL1 and SQL2 will get mapped to the default cluster coordinator. Say MSDTC1 was configured first then MSDTC1 will become the default cluster coordinator and both SQL1 and SQL2 will use MSDTC1. In order to configure SQL2 to use MSDTC2, we will explicitly need to use the msdtc.exe command with the –tmMappingSet option.

Is my understanding correct? Can someone confirm?

How can I tell which MSDTC resource is being used by SQL?

Say we somehow know that SQL1 is using MSDTC1, what happens if MSDTC1 fails. Will SQL1 use MSDTC2 or will it use the local MSDTC?

Thanks for your response in advance.

re: Plumbing 101: A bookshelf list

John Apps — Wed, 12 Nov 2008 21:11:21 GMT

One other book, the second edition of which is to be published shortly, is "Principles of Transaction Processing" written by Eric Newcomer and Phil Bernstein (www.amazon.com/.../ref=sr_1_4).

Somewhat lighter (pun intended) reading than the Gray book and an excellent complement to it.

Cheers, John

re: Plumbing 101: A bookshelf list

Mujtaba Syed — Wed, 12 Nov 2008 18:29:51 GMT

Distributed Algorithms by Nancy Lynch is also an excellent book.

www.amazon.com/.../ref=sr_1_1

Plumbing 101: A bookshelf list

Jim Johnson's Blog — Wed, 05 Nov 2008 14:07:34 GMT

As I mentioned in a previous post , I'm essentially a plumber. I work on infrastructure software

re: MSDTC changes in WS2008, Part 3: Cluster features

Vikram Sahijwani — Mon, 20 Oct 2008 23:40:20 GMT

[Jim: I asked the transactions team to look into this. Vikram took at look at it and posted this reply.]

Hi Dror,

You are right. The enum definition should indeed be:

typedef enum APPLICATIONTYPE

{

LOCAL_APPLICATIONTYPE,

CLUSTERRESOURCE_APPLICATIONTYPE

} APPLICATIONTYPE;

Fortunately, as you mentioned, the work-around is quite simple. If you are using C, then replace the enum definition in xolehlp.h with the one I typed above.

-Vikram

re: MSDTC changes in WS2008, Part 3: Cluster features

Dror Harari — Tue, 16 Sep 2008 15:16:16 GMT

Note that the APPLICATIONTYPE enum definition will give you trouble if you write in C rather than in C++. For anyone using C to call this fix the definition in xolehlp.h to:

typedef enum APPLICATIONTYPE

{

LOCAL_APPLICATIONTYPE,

CLUSTERRESOURCE_APPLICATIONTYPE

} APPLICATIONTYPE;

re: MSDTC changes in WS2008, Part 3: Cluster features

Dror Harari — Tue, 16 Sep 2008 14:52:51 GMT

I find it strange that you manage to compile with this definition of _OLE_TM_CONFIG_PARAMS_V2. I am including xolehlp.h in my code and the compiler (VS 2008 SP1) yells:

Error 6 error C2061: syntax error : identifier 'APPLICATIONTYPE' c:\program files\microsoft sdks\windows\v6.1\include\xolehlp.h 65 MyTxnPrj

The problem seems to be with the enum definition for APPLICATIONTYPE which is (as you wrote):

typedef enum APPLICATIONTYPE

{

LOCAL_APPLICATIONTYPE,

CLUSTERRESOURCE_APPLICATIONTYPE

};

but should have been:

typedef enum APPLICATIONTYPE

{

LOCAL_APPLICATIONTYPE,

CLUSTERRESOURCE_APPLICATIONTYPE

} APPLICATIONTYPE;

Makes me wonder what setting am I missing to make it work...

re: Upcoming webcasts

Miguel Gasca — Sat, 23 Aug 2008 18:32:54 GMT

Hey Jim, just to prod you a bit, any chance of you giving any insight into what the Transactions team is working on nowadays?

Miguel

re: Building the transaction protocol documents

Miguel Gasca — Sat, 23 Aug 2008 18:29:54 GMT

Intense period of activity indeed! It made me smile reading through the docs for a bit.

re: The end of an era

Joseph Healy — Fri, 22 Aug 2008 08:47:46 GMT

Ah, Spitbrook - was there '85-'87 and lived up in Francestown. Now that takes me back a piece...

RIP...

re: MSDTC changes in WS2008, Part 3: Cluster features

Uttam Parui — Thu, 21 Aug 2008 04:46:58 GMT

Thanks Jim. This is very helpful. As I was testing, I had created two MSDTC resources in seperate groups (different from the SQL Server group). In that case the cluster resource name needs to be the MSDTC cluster resource, right? If not then how will it know which MSDTC to map to.

Also, is there a way we can test if SQL Server is infact using the right MSDTC resource?

re: Upcoming webcasts

jim-johnson — Mon, 14 Jul 2008 22:11:36 GMT

It looks like at least some are. I went to the MSDN webcasts page (using the link above) and looked at the on-demand list. I found Juval's, for instance, at www.microsoft.com/.../webcastdetails.aspx

I've updated the links.

Jim.