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Standby configuration clean up and standardization. Emil Pilecki , IT-DB. Standby configuration cleanup. On both primary and stanbdby ensure that DB_UNIQUE_NAME is set LOG_ARCHIVE_CONFIG=DG_CONFIG is set and lists all unique names in the configuration
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Standby configuration clean up and standardization Emil Pilecki, IT-DB
Standby configuration cleanup • On both primary and stanbdby ensure that • DB_UNIQUE_NAME is set • LOG_ARCHIVE_CONFIG=DG_CONFIG is set and lists all unique names in the configuration • useful for multi-standby configurations, especially in synch mode and with broker • Always specify DB_UNIQUE_NAME for each remote LOG_ARCHIVE_DEST_n destination • LGWR option is removed from LOG_ARCHIVE_DEST_n • obsolete in 11.2
Standby configuration cleanup • Symmetric configuration for faster switchover • Configure redo transport on standby for easier switchover/failover • now often not configured • Configuration that use downstream capture are at risk if standby opened in RW mode and starts shipping redo • Use LOG_ARCHIVE_DEST_STATE_n=DEFER to safeguard from accidental redo shipment from standby • set to ENABLE before switchover • Use LOG_ARCHIVE_CONFIG=NORECEIVE/NOSEND as a 2nd safety measure for configurations with downstream • to be tested if it works correctly • remove this settings before switchover
Standby configuration in LDAP • <SC_DB_UNIQUE_NAME> - already in LDAP • Link between primary and standbys entities defined in LDAP • to quickly see what standby databases are configured fora given primary • useful for monitoring tools, such as RACMON • <SC_STANDBYS> - optional sub-entity of DB entity as <SC_HOSTS> • <SC_STANDBY_ID=1> - first standby • <SC_STANDBY_ENTITY> - first standby DB entity name • <SC_STANDBY_TYPE> - disaster recovery or active (exposed to users) • <SC_STANDBY_ID=2> - second standby • <SC_STANDBY_ENTITY> - second standby DB entity name • <SC_STANDBY_TYPE> - disaster recovery or active (exposed to users)
Standby naming conventions • Standardize naming for standby databases • Unify! Use the same naming scheme for • LDAP entities • DB_UNIQUE_NAME parameter • Local TNS aliases • Proposal • dbname – primary database • dbname_dg_racX – standby for disaster recovery • dbname_adg_racX – active standby exposed to end users
Standby naming conventions • Replace names in LDAP and DB_UNIQUE_NAME • dbname_standby_racX => dbname_dg_racX • Remove excess local TNS aliases • dbname_primary and dbname_standby • dbname_standby_racX • aliases pointing to specific instances on standby databases • There should be only one local TNS alias per database in the configuration • dbname – always pointing to the primary • dbname_dg_racX – pointing to the specific DR standby • dbname_adg_racX – pointing to the specific active standby (exposed to end users) • Retain TNS aliases pointing to specific instances on primary • useful for troubleshooting and data pump
Standby for migration purposes • Temporary standby DBs created for migration purposes are not covered by the rules describedin this presentation • Symmetric configuration is not needed • DB_UNIQUE_NAMEdon’t have to be set • LDAP standby information can be omitted • Local TNS aliases should eventually be the same as on primary
Conclusions • Use the new naming convention and setup guidelines while configuring new standby databases • Gradual clean up of existing databases to make them compliant with the new guidelines • Deadline for non-PROD: October2012 • Deadline for PROD: November2012 • LDAP changes not yet implemented – will be announced separately when ready