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Use

Use command hss_enable to switch a database into the high availibility mode. It makes the database part of a hot standby system. Simultaneously it makes this database the master database of the hot standby system.

There are two ways to set up a hot standby system, which are independent of the log mode used:

With the first solution, the log entries are simultaneously written to the log area of the master database and to the log area of the standby database. A hot standby system of this type consists of one master and one standby database, respectively.

With the second solution, the master and the standby databases share the log area of the master database. The hot standby system comprises one master database and one or multiple standby databases.

Use command hss_disable to switch off the high availability mode.

Recommendation

In a hot standby system, always use the virtual server name to administer a database.

Prerequisites

  • You can only set up a hot standby system if your software installation assures that the system continuously checks whether the master database is available.

  • To set up a hot standby system, you need a master database. You can use an existing SAP MaxDB database or create a new one.

  • The database to become the master database is on that computer to which the virtual server name has been assigned.

  • You are connected to the database on the virtual server.

  • hss_enable: You have the server permission ParamFull.

    hss_disable: You have the server permission InstallMgm.

  • For the solution Hot Standby System (With Shared Log Arey), the database to become the master database must be in the OFFLINE operational state.

Structure

hss_enable lib=<hs_storage_dll> node=<virtual_server_name>

hss_disable

Option

Description

<hs_storage_dll>

For the solution based on the shared log area, specify the name of the library required for controlling the memory management system.

<virtual_server_name>

Name of the virtual server to be used by the application to connect to the database
Result

OK

In the event of errors, see Reply Format.

Example

Call Database Manager CLI, log on as the operator OLEG with the password MONDAY, connect to the database DEMODB on the database computer using its virtual server name HOTEL_VIRTUAL. Specify the library libhsscopy for triggering the memory management system and the virtual server name to be used by the application to connect to the database:

> dbmcli -u OLEG,MONDAY -d DEMODB -n HOTEL_VIRTUAL hss_enable lib=libhsscopy node=HOTEL_VIRTUAL

OK

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