When taking Oracle GoldenGate into the Cloud, I revisited the role of Oracle GoldenGate in Oracle Maximum Availability Architecture (MAA). The following is a brief summary of it:
- Oracle GoldenGate and it's cloud service are part of the Oracle MAA Platinum architecture.
- Oracle GoldenGate and it's cloud service are used for zero downtime migration and maintenance.
- Oracle GoldenGate and it's cloud service require database object level operations.
- Oracle GoldenGate and it's cloud service are restricted by its asynchronous replication which could have a potential data loss[2][3].
What is Oracle MAA?
Oracle MAA recommends stacked reference architectures for implementing highly available Oracle Database systems. The goal is to reduce the risks and costs of the database outages,
Oracle MAA recommends stacked reference architectures for implementing highly available Oracle Database systems. The goal is to reduce the risks and costs of the database outages,
There are two types of database outages: planned and unplanned outages[5].
- The Planned Outage includes downtime to perform patching, maintenance (Online Maintenance) or upgrades (GoldenGate Zero Downtime Migration, Active/DataGuard Rolling Upgrade).
- The Unplanned Outage involves all kinds of failures including the server failures and the data corruptions. The Server Failures refer to failures like instance failure (RAC) and site failure (Data Guard/Active Data Guard). The Data Corruptions include loss of data due to human errors (flashback, detect and repair) or disk failures (ASM database files system).
- Bronze - is for the dev/test and single tenant production systems, which relies on database auto-restart and the backups to protect data and restore availability. Oracle Recover Manager (RMAN) with Oracle Database Enterprise Edition and Oracle DBaaS Enterprise Cloud Service with Oracle Backup Cloud Service are recommended. Local backup is suggested for fast recovery. Multi-site backup is recommended to avoid site outages. This level of HA requires a cold restart and the interruption when recovering from the backups. The data between the outage and the last backup are also lost. This level of MAA ensures that Instances can be recovered from backups.
- Silver - is for the departmental production systems. On top of Bronze, Oracle RAC (Active-Active Database Clustering) is added to protect database instance or server failure. Oracle Database Enterprise Edition with Oracle RAC and Enterprise Manager and Oracle DBaaS Extreme Performance with Oracle Database Backup Cloud Service are recommended. Another option is to use Data Guard to maintain a local standby database to protect data corruptions, human error, cluster outages, network faults and database upgrades. This level of MAA ensures that there is minimal or zero downtime during the instance/server of failure.
- Gold - is for business critical systems. On top of Silver, Active Data Guard is added to create remote standby database. Active Data Guard provides the physical replication with zero data loss, fast fail-over, incremental backups, and automatics block corruption repairs. This level of MAA ensures minimal or zero downtime during site outage.
- Platinum - is for mission critical systems which require the outage to be transparent to the users. On top of Silver, Oracle Application Continuity is added to reply in-flight transactions; Active Data Guard Far Sync for zero data loss at a distance; Oracle GoldenGate or Oracle GoldenGate Cloud Service for zero downtime migration and Edition-based Redefinition for zero-downtime application upgrades. This level of MAA makes the outage transparent to users.
What is the Role of Oracle GoldenGate?
From the Oracle MAA white paper [1], Oracle GoldenGate is for zero-downtime maintenance and migration during planned downtime, NOT for the active-active high availability. Oracle GoldenGate solution also requires understanding application objects at the database level. The Oracle GoldenGate for Zero Downtime Migration blog has further discussion on this type of implementation.
From the Oracle MAA white paper [1], Oracle GoldenGate is for zero-downtime maintenance and migration during planned downtime, NOT for the active-active high availability. Oracle GoldenGate solution also requires understanding application objects at the database level. The Oracle GoldenGate for Zero Downtime Migration blog has further discussion on this type of implementation.
Resources
- Oracle MAA Reference Architectures Oracle Database High Availability On-Premises and in the Cloud, Technical White Paper, Feb 2016
- Oracle Active Data Guard and Oracle GoldenGate (a comparison), Oracle.com
- Best Practice: Oracle Active Data Guard and Oracle GoldenGate, Oracle Database 12.1 documentation
- Maximize Availability with Oracle Database 11g, Sept 4, 2011, Oracle Screen-cast, YouTube
- Oracle Database Maximum Availability Architecture, Jan 22, 2008, YouTube
- Oracle GoldenGate Cloud Service for Oracle MAA (PPT)
- Oracle MAA Reference Customers