Category Archives: Analysis Services

MSC-ERR-0008 An error has occured at the transport layer and OP-ERR-0181 At least one invalid member – Cognos and SSAS errors


MSC-ERR-0008 An error has occurred at the transport layer and OP-ERR-0181 At least one invalid member – Cognos and SSAS errors

A client has found a solution to two errors occurring in an environment with Cognos 10.1 and SQL Server 2008.

  • MSC-ERR-008 An error as occurred at the transport layer.
  • OP-ERR-0181 At least one invalid member reference was encountered in the query.

A hot-fix was applied to Windows as described in these two following articles and initial testing has been positive. The scenario is a single sign-on Cognos environment with Active Directory using Kerberos to authenticate to SQL Server Analysis Services 2008. The errors seemed intermittent.

http://blogs.msdn.com/b/psssql/archive/2009/04/03/errors-may-occur-after-configuring-analysis-services-to-use-kerberos-authentication-on-advanced-encryption-standard-aware-operating-systems.aspx

http://support.microsoft.com/kb/969083

IBM Cognos BI report error against SSAS – At least one invalid member reference was encountered in the query


At least one invalid member reference was encountered in the query

Problem

When encountering this error message “At least one invalid member reference was encountered in the query…”, when reporting against SQL Server Analysis Services with IBM Cognos Report Studio 10.1 using a crosstab, the problem may be caused by having no data in a row and column intersection.

Solution

A potential solution is to go to the query properties and, under Query Hints, change Suppression to Nulls.  This can also improve performance as it can reduce the data returned from the cube.  Note that this is a different setting than the Zero Suppression that suppress rows and/or columns.  It’s on the query, not the reporting object.

There could be many reasons that a missing member reference was encountered, but this simple change often fixes the problem.

Errors in the OLAP storage engine: A duplicate attribute key has been found when processing


Duplicate attribute key error

A frequent error when processing an SSAS cube begins “Errors in the OLAP storage engine: A duplicate attribute key has been found when processing”. I have found that this is usually one of two conditions:

Typical Causes

  1. An actual duplicate key is found where a value for a child in a hierarchy occurs with two different parent values.
  2. A value for a data item is NULL.

Solution for actual duplicate key

The former is easier to discover and can be resolved by using a compound key for the parent that includes the child key. Look for it when the field in question is part of a hierarchy.  A child can only have one parent.

Solution for null data

The latter can be confounding because the error message is often misleading. It can show a value in the error message, not indicating that the real underlying cause is the NULL value. This can be repaired by using a COALESCE statement to replace a NULL with a value such as ‘Unknown’ or simply ”.

A good practice is to use views as the source of data to a cube, rather than making any modifications within the SSAS data source view. It is in the view that I add the COALESCE function around the data item.

For example, if there are nulls in the MIDDLE_NAME data item, the view

CREATE VIEW vwPeople AS

SELECT FIRST_NAME [First Name],
COALESCE(MIDDLE_NAME,”) [Middle Name],
LAST_NAME [Last Name]
FROM PEOPLE

will use the MIDDLE_NAME value for [Middle Name] unless it is NULL and then will use the empty string instead.