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Changing Order of Object Server fields in Omnibus for Probe Failover and Failback

Technical Blog Post


Abstract

Changing Order of Object Server fields in Omnibus for Probe Failover and Failback

Body

For automatic failover and failback of probes between Object Servers, both Object Servers must have identical alerts.status tables. Both the column type and column size must be the same, and the ordinal position of each column must match.

Reordering columns beetween Object Servers can be a difficult task. It isn't possible to delete and recreate columns manually, since deleting any column also deletes an object that reference that column such as triggers or tools. Instead, the Backup Object Server should be recreated and cloned from the Primary Object Server.

 

The following procedure can be used to clone a Primary Object Server to a Backup Object Server.

Requirements:

  • Omnibus 7.3.1 or later
  • Primary Object Server for example AGG_P
  • Backup Object Server for example AGG_B
  • Ensure there are no custom triggers or procedures which exist only on the Backup Object Server, or they would be removed. Copy any custom triggers or procedures which exist only on the Backup Object Server to the Primary Object Server prior to executing.
  • Ensure there are no custom users which exist only on the Backup Object Server. All users would be recreated with the login data fromt he Primary Object Server.                                                              

Procedure to clone Primary Object Server AGG_P to Backup Object Server AGG_B                                                                        

  1. Shutdown the Backup Object Server and the bi-directional failover Object Server gateway.
  2. Create a backup of the Backup Object Server database files in $OMNIHOME/db/ just in case.          

cp $OMNIHOME/db/AGG_B $OMNIHOME/db/AGG_B.backup

  1. On the Primary Object Server, run nco_osreport with the -dbinit option, this will create several sql files

mkdir /tmp/sqlfiles

$OMHIHOME/bin/nco_osreport -dbinit -server AGG_P -directory /tmp/sqlfiles -user root -password ""

  1. Copy the sql files created by nco_osreport in /tmp/sqlfiles to the Backup Object Server                                                    
  2. On the Backup Object Server, recreate the AGG_B Object Server with the following command, using the sqlfiles copied from AGG_P. Note, this will overwrite the current Object Server.                                                           

                                                                        
$NCHOME/omnibus/bin/nco_dbinit -server AGG_B -systemfile system.sql -applicationfile application.sql -alertsdata  -alertsdatafile alertsdata.sql -desktopfile desktop.sql -automationfile automation.sql -securityfile security.sql -force                        
 

  1. Start the Backup Object Server AGG_B
  2. Login to AGG_B via the Administrator. Set properties BackupObjectServer to TRUE and ActingPrimary to FALSE. Ensure the primary_only trigger group is disabled.                                                     
  3. Start the bi-directional Object Server failover gateway.             


These steps only work on Omnibus 7.3.1 and later since nco_osreport was not available in previous versions.

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UID

ibm11082115