The following is a root cause analysis describing the cube processing issues recently experienced by installing the SQL CU7 and later patch. As this document will detail, the issues seem to stem from a SQL patch made available by Microsoft in the early July timeframe which has led to adverse effects on cube processing in SQL Server Analysis Services.
After applying the CU7 SQL patch in the environment during ICA nightly processing, SQL Server Analysis Services is adversely affected and caused cube processing to hang indefinitely. After checking numerous settings in Analysis Services and rebooting the server without a change in behavior, manually processing the cube proves successful, however only in a sequential fashion. By nature, serial processing proved to be much more time consuming, increasing the overall cube processing time from 30 minutes under the former parallel setting, to an hour and a half. This behavior was later replicated in Bay Dynamics’ internal environment by applying the same SQL patch. After removing that patch, cube processing was allowed to continue successfully, further underscoring the point that this issue was directly related to the security update provided by Microsoft.
Duration of the nightly job is negatively impacted by tripling the time it takes to process the cube, resulting in delayed updates to the dataset within Analyzer.
Processing times are affected after installing the security update for SQL Server 2016 SP2 CU7, published 7/7/2019 to address CVE-2019-1068, as per the Microsoft Support site.
This has also been observed in later CU versions, as current as Cu12 for SQL Server 2016 are affected by this issue
ICA 6.5.2.X, SQL Server 2016
The process in the attached document should be followed as a workaround to the issue described above, which will allow for the cube to process successfully. Note that as previously mentioned, this may increase the duration of cube processing, however it will allow data in Risk Fabric to update until Microsoft can provide further guidance on remediation.