Removing a Host from a Scale-Out System

In a distributed SAP HANA system, tables and table partitions are assigned to an index server on a specific host at their time of creation, but this assignment can be changed. In certain situations, it is even necessary. You can use SAP HANA cockpit 2.0 together with the SAP HANA Database Explorer to execute automatic redistribution operations.

There are several occasions when tables or partitions of tables need to be moved to other servers. For example, if you plan to remove a host from your system, then you first need to move all the data on that host to the other hosts in the system. Redistributing tables may also be useful if you suspect that the current distribution is no longer optimal.

Although it is possible to move tables and table partitions manually from one host to another, this is neither practical nor feasible for a large-scale redistribution of data.

1. From the SAP HANA Cockpit 2.0 – Database Directory screen, choose the Open SQL Console link.

2. In the Database Explorer, select your <Tenant>@< SID > and click on the Open SQL Console icon in the top-left corner.

3. In the SQL Console, execute the following commands:

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   call SYS.UPDATE_LANDSCAPE_CONFIGURATION( 'SET REMOVE','<host>' );
   call REORG_GENERATE(2,'');
   select * from SYS.REORG_STEPS;
   call REORG_EXECUTE(?);

4. In the Host Failover screen, check the status of the host in the column Remove Status. If there is no column Remove Status, then add it using the Settings options.

5. If the column Remove Status has the value REORG FINISHED or REORG NOT REQUIR, the host can be removed from the system.

6. Use the resident hdblcm, hdblcmgui, or the web-based hdblcm tool to remove the host from the multi-host SAP HANA system.

You can remove hosts from an SAP HANA system using the SAP HANA database lifecycle manager (HDBLCM) in the graphical user interface or the command-line interface.

• You have the credentials of the root user and the <sid>adm user.

• The SAP HANA system has been installed with the SAP HANA database lifecycle manager.

• The <sid>adm user has read and execute permissions for the directory that contains the installation medium.

If you want to remove a host that runs the coordinator name server, another host that will take over the role of the coordinator name server must be up and running.

You can remove hosts from an SAP HANA system using the SAP HANA database lifecycle manager web user interface.

• You require the credentials of the root user and the <sid>adm user.

• The SAP HANA system has been installed with the SAP HANA database lifecycle manager.

• The <sid>adm user has read and execute permissions for the directory that contains the installation medium.

• Communication port 1129 is open for SSL communication with the SAP Host Agent.

If you want to remove a host that runs the coordinator name server, another host that will take over the role of the coordinator name server must be up and running.

On Microsoft Windows:

• Internet Explorer - Version 9 or higher

  If you are running Internet Explorer version 9, ensure that your browser is not running in compatibility mode with your SAP HANA host. You can check this in your browser by choosing Tools → Compatibility → View Settings.

• Microsoft Edge

• Mozilla Firefox - Latest version and Extended Support Release

• Google Chrome - Latest version

  On SUSE Linux:

• Mozilla Firefox with XULRunner 10.0.4 ESR

  On Mac OS:

• Safari 5.1 or higher