msmdpump, how does it work?

I am using AS2000, i have msmdpump setup properly and its working fine, but when i look at the code of msolap.asp i was confused as to how is the mdx query passed to msmdpump.dll as i couldn't see any parameters being passed to msmdpump, i could just find

//no parameter passed here

pump.ReadData

So how does msmdpump know as to which mdx query it has to process?. I badly need to find out which mdx query is the msmdpump processing ,or which dimensions it is querying.

I took a dump of the data being posted to the msolap.asp page from an excel client by writing an isapi filter and writing the data on the SF_NOTIFY_READ_RAW_DATA event,here it is

--


R E Q U E S T = H ; S T A T E = 0 ; T Y P E = b ; N A M E = FoodMart 2000 ; V E R = 2 4 8 ; L A S T = N ; T Y P E = m ; N A M E = Sales; V E R = 4 4 0 ; L A S T = Y ; D V E R = 3 8 8 ; C V E R = 0 ; POST /msolap.asp HTTP/1.1

User-Agent: Light DCube

Host: localhost:8080

Content-Length: 268

Connection: Keep-Alive

Cache-Control: no-cache

Cookie: ASPSESSIONIDQASQBQST=BOFBOCMCIMPOFJEECELBGBJD


R E Q U E S T = H ; S T A T E = 0 ; T Y P E = b ; N A M E =FoodMart 2000 ; V E R = 2 4 8 ; L A S T = N ; T Y P E = m ; N A M E = HR ; V E R = 4 4 1 ; L A S T = Y ; D V E R = 4 0 4 ; C V E R = 0 ; POST /msolap.asp HTTP/1.1

User-Agent: Light DCube

Host: localhost:8080

Content-Length: 252

Connection: Keep-Alive

Cache-Control: no-cache

Cookie: ASPSESSIONIDQASQBQST=BOFBOCMCIMPOFJEECELBGBJD

I couldn't make anything out of it though

I also tried referencing msmdpump.dll to a .net project and i could see functions like

OnStartPage(object piUnk) .

looked to me as if piUnk is a reference to some asp com object interface, but don't know for sure.

Any help is appreceiated

In AS2000, the MDX query is not passed from the client to the server. Client code, i.e. msolap80.dll does all the parsing etc. The communication with server happens on much lower level.|||

Thanks for the reply , so is there anyway to know which mdx query is being passed to the as2000 server to process, or if that's not possible, then is it possible to know which dimension is the client trying to access.

Actually the problem is that we have as2000 server in domain A ,the webserver is in domain B and the users are in domain C.

Now B trusts C, A trusts B. We want to give users in C direct permission to the cubes so we have setup msmdpump. But the problem is that we want the users in C to have access to only a particular value of a dimension ,say dimRestricted, and since A doesn't know the users in C, we can't directly add users in C to the AS2000 client roles. So we have created users in B and have added them to the roles in AS2000 server,one for each value of dimRestricted(the number of entries in dimRestricted is constant and is less then 10).When a client from C tries to access the cubes we check whether he has access to the cube and depending on the dimension of dimRestricted which he is trying to access we impersonate the corresponding user in domain B.

But for that to happen we need to find out the value of dimRestricted dimension the client is trying to access.

Any clues or hints are well appreciated.

|||I suggest that you create a mapping between users in domain C and users in domain B. This way, when user from C is authenticated - you will be able to map him to user in domain B. The mapping will work purely on user per user basis, and won't need to know anything about cubes or dimensions.|||

Thanks for the quick reply,

That's pretty much what we are doing, so what we have is that we have AD groups in C each of which is supposed to have access to a particular value of dimension dimRestricted and a corresponding user in Domain B to which we give access to that value of dimRestricted dimension.

So suppose we have AD group named C1 in C , which is supposed to have access to value "panasonic" in dimension dimRestricted, so there is a corresponding user B1

in B which only has access to panasonic value in dimRestricted.

Similarly we have AD group named C2 in C , which is supposed to have access to value "samsong" in dimension dimRestricted, so there is a corresponding user B2 in B which only has access to samsong value in dimRestricted.

But now there can be a special user who might be both in C1 and C2, the code just checks that if user belongs to C1 then impersonate to B1 ,if C2 then B2. Now if he requests to see Measures for dimension "panasonic" , he would be impersonated to B1 and everything would be fine, but what if he tries to see for "samsong", our code does't knows which dimension he is trying to access and would again impersonate to B1 and he would not get any data whereas he should.

So we need to know which value of dimRestricted he is trying to access.

Thanks for the help.

|||My suggestion was that you have true one-to-one mapping between users in C and in B. If you have user C3 which should belong to two different roles, you need to create corresponding user B3, who will belong to these two roles, and then when you detect C3, you impersonate B3. I.e. you map user to user, not group to user. There is a management overhead with this solution, but this is the only way you can get it working with AS2000.|||

Thanks for the reply,

Yes that's what we are planning to do, and its specifically for this huge number of users that we might have to create in domain B(for which we may not even get permission) that i was looking for finding some way out of finding the dimension that the client is accessing .

Thanks anyways!.