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Removal of ID Server as a Single Point of FailureLocate this document in the navigation structure

In versions of SAP Replication Server prior to 15.7.1 SP300, there could be only one ID Server in a replication domain. This design had the following limitations and concerns:

  • Single point of failure: If the ID Server was inaccessible or down, you could not add a new Replication Server or database to a domain.

  • Inability to move to a different backup server: After a particular Replication Server was selected as the ID Server, it was not possible to change or move to a different Replication Server.

To resolve these problems, a Backup ID Server has been introduced in SAP Replication Server 15.7.1 SP300. This reduces the risk of single point of failure, and improves overall availability with the introduction of a Backup ID Server. The solution works as follows:

  • Currently, there is only one active ID Server in a replication domain. Replication Server knows about, and contacts only this ID Server for ID Management. Also, the Backup ID Server syncs through a Remote Procedure Call (RPC) whenever there is any change in the Primary ID Server.

  • When the Primary ID Server goes down, dies, or crashes, RSA repairs the Primary ID Server, or promotes the Backup ID Server as the Primary ID Server.

Replication Command Language (RCL) Commands to perform related tasks are listed and described below:

  • sysadmin idserver, config: This command helps you to configure ID Servers, and may change the Replication Server configuration file and RSSD. You can use it to show current ID Server configurations, and to configure Primary/Backup ID Servers.

    Syntax: sysadmin idserver[, config[, primary|backup[, rsname, username, pwd]]]

    Examples:

    1. Display all configurations about ID servers, including the Primary and Backup ID Servers:

      • sysadmin idserver

      • sysadmin idserver, config

    2. Show configurations of Primary or Backup ID Server only:

      • sysadmin idserver, config, 'primary'

      • sysadmin idserver, config, backup

    3. Configure Primary ID Server for a Replication Server:

      • sysadmin idserver, config, primary, rsname, username, pwd

    4. Configure the Backup ID Server:

      • sysadmin idserver, config, backup, rsname, username, pwd

  • sysadmin idserver, sync: This command enables you to manually force a sync between the Primary and Backup ID Servers, and can only be executed on the Primary ID Server. When you run the command, the sync up happens instantly.

    Syntax: sysadmin idserver, sync