Ragged Dimension Hierarchies causing PA2.0 crashes

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PavoGa
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Ragged Dimension Hierarchies causing PA2.0 crashes

Post by PavoGa »

We are having a major issue with PA2.0 crashing when opening a cube through Architect a second time if one of the dimensions contains a ragged or unbalanced hierarchy. It will also crash if using the cube viewer and opening the subset editor on said dimension. This behavior is consistent and repeatable.

This behavior does not happen in PAW, but performance is AWFUL. For example, if one closes a consolidation that has been drilled down on and the consolidation has five children, it literally takes 45 seconds+ for the drill down to close. ???! This is occurring on the same dimension.

The cube is small (8MB) and has 9 dimensions. The two largest dimensions have approximately 21K and 12K members. But that is immaterial because as long as we create a dimension with the structure described below and put it in a cube with three+ dimensions (have not seen this in two dimension cubes), whether the cube is populated or empty, the server crashes.

Now for some more fun. Here is the basic structure for the dimension causing the problems:

Code: Select all

+Unregistered
  -215-040-001
  -215-040-002
+All Accounts
  +Liabilities
    +Payroll
      -215-040-003
  +Revenue
    ...
  +Cost
    ...
  +Expenses
    ...
This crashes. Now here is the M. Night Shyamalan twist that does not make a lot of sense: switch the position of the two consolidations, Unregistered and All Accounts to where All Accounts comes first and the crashing stops.

So the questions are has anyone else experienced this? Is this a known "feature?" If so, is there documentation or a workaround, a set of rules for dimension building perhaps?

Thanks!
Ty
Cleveland, TN
dr.nybble
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Re: Ragged Dimension Hierarchies causing PA2.0 crashes

Post by dr.nybble »

Contact support so you can supply your model to the TM1 Server development team.
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paulsimon
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Re: Ragged Dimension Hierarchies causing PA2.0 crashes

Post by paulsimon »

Hi

By all means contact IBM Support as this looks like a bug. We contacted them over a similar issue in PA 2.0.3 (which still exists in PA 2.0.5). Our issue seems to be related to alternate hierarchies leading to the server using incredible amounts of memory because it generates MUNs for every possible combination, which in turn leads to a crash. We contacted IBM Support back in May and we are still waiting for an answer! The Account Manager has gone AWOL and we are getting no where with them. But as Dr Nybble clearly works for IBM perhaps he could prod them to do something about this serious bug (End of why do we pay for support rant!)

In our case this was a Day level Time dimension, with multiple alternate hierarchies and a lot of elements. Fortunately, as we could get by without all the alternate hierarchies, we worked around the bug by removing all alternate hierarchies from the dimension. Clearly that is not always going to be an option.

Your issue may be different as it does not sound as though you have that many elements, but it is probably related.

As a suggested workaround, first change your dimension properties to BYHIERARCHY and BYNAME which should give you All Accounts, then Unregistered, which as you say, seems to resolve the problem.

If that doesn't solve it then try this - we always have a single top level consolidation so try joining your Unregistered and All Accounts consolidations to an All Accounts Hierarchy consolidation (use a 0 weight on eg the link from Unregistered to prevent any double counting. That may help. However, if the issue is related to MUNs it might potentially make things worse by introducing another level into the MUN string.

Regards

Paul Simon
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PavoGa
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Re: Ragged Dimension Hierarchies causing PA2.0 crashes

Post by PavoGa »

Thanks for the advice, Paul. Will look at those suggestions. I read the MUN thread discussion and posted results of testing I'd performed there as well.

Dr. Nybble, we will be sending everything to IBM next week.
Ty
Cleveland, TN
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