KB45399: New Feature in MicroStrategy 9.3.1: Maintenance Mode: Ability to retain Intelligent Cubes, Caches and History on 'Normal Shutdown' of a server node in an Intelligence Server cluster.

In prior versions of the Strategy Intelligence Server, when an Intelligence Server node in a cluster was shut down (Normal Shutdown), the node would also remove from the shared cluster resources any Intelligent Cubes, caches or history messages that had been created by that node (even if it was part of the cluster at the time of the resource creation). On the other hand, an abnormal termination/killing of the Intelligence Server process on a clustered node would keep the resources in the cluster for access from other nodes.
 
With the release of  Strategy 9.3.1, the Intelligence Server can now be configured to keep the clustered resources in the surviving Intelligence Server cluster even if the node is shutdown normally. By default, this feature "Maintenance Mode" is not enabled and must be manually enabled on each node of the Intelligence Server to be functional. The setting is applied in the registry (or MSIReg.reg on Unix/Linux installations) as noted below. After enabling maintenance mode, when one node of the cluster is shut down, it is seen in maintenance mode when viewed from the cluster monitor of the other node(s) in the cluster:
 
Refer to the following Strategy Knowledge Base documents for information on the additional registry settings discussed in the steps below: 

• KB221178: How does the registry setting 'Cluster Synch Check Duplicate Cubes' work in a clustered environment in Strategy 9.4.1 and later 
• KB47195: In a Strategy 9.3.x - 9.4.x clustered environment, when one of the machines hosting the Strategy Intelligence Servers is shut down, the performance of other Strategy Intelligence Servers in the cluster is affected

 
Windows
Implement the steps below to enable maintenance mode. These changes should be implemented on all the nodes of the cluster:
 

• Shut down Strategy Intelligence Server(s) where the change needs to be done.
• Open the Windows registry and navigate to the following location: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Strategy\DSS Server\Castor.
• Create a new DWORD (32-bit) value and name the entry “MaintenanceModeEnabled” and set its value to 1.The registry location should look as shown in the screenshot below. 
  

• Also, it is recommended for users to create a registry entry called

  SkipClusterChecking

  . This entry should also be in the added in the same location as given in Step 3. It should also be created as a new DWORD (32-bit) and the value of the entry should be set to 1. The two settings should look in the registry as given below:
  
  

• In addition, it is recommended to create a setting called '

  Cluster Synch Check Duplicate Cubes

  ' in Strategy Intelligence Server 9.4.1 and later. This should be created as a new DWORD (32-bit) in the location: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Strategy\Data Sources\CastorServer and the value of this entry should be set to 1.
  
   

Note: To disable maintenance mode, change the value of the newly created registry entry to 0 or delete these entries from the registry. 
 
UNIX/Linux
Implement the steps below to enable maintenance mode. These changes should be implemented on all the nodes of the cluster: 
 

1. Stop Strategy Intelligence Server(s) where the change needs to be done. 
2. Create a backup of the MSIReg.reg file found in the home directory of the Strategy installation.
3. Edit the MSIReg.reg file, which is found in the Strategy home directory ($MSTR_HOME_PATH).
4. Find the section [HKEY_LOCAL_MACHINE\SOFTWARE\Strategy\DSS Server\Castor]. 
5. Add the following entry to enable the setting (just below the entry that reads "IgnoreAllExceptions"=dword:00000000:
   
   

   "MaintenanceModeEnabled"=dword:00000001

   
    
6. It is recommended for users to create a registry entry called

   SkipClusterChecking

   . This should also be added to the same location as given in Step 4. It should be added as given below:
   
   

   "SkipClusterChecking"=dword:00000001

   
    
7. Also, in Strategy Intelligence Server 9.4.1 and later, the following registry entry is also recommended to be added in the location: [HKEY_LOCAL_MACHINE\SOFTWARE\Strategy\Data Sources\CastorServer]
   
   

   "Cluster Synch Check Duplicate Cubes"=dword:00000001

   
    
8. Start the Intelligence Server for the change to take effect.

 Note: "SkipClusterChecking" entry is enabled by default on 9.4.1 HotFix 9 and newer, and no longer required in 10.x versions.
 
WARNING:
Modifying registry values incorrectly may cause serious, system-wide problems that may require the re-installation of Microsoft Windows. Any edit of the registry is done at the user's own risk. Since these are user-initiated changes, they are not covered by any Strategy warranty. If using Microsoft Windows, the user should backup the registry and/or update an Emergency Repair Disk (ERD) prior to alterations.
45399