Oracle RDS GoldenGate support

Oracle GoldenGate can be used with Amazon RDS for Oracle for active-active database replication, zero-downtime migration and upgrades, disaster recovery and data protection, and cross region replication. 

More information here: http://aws.amazon.com/about-aws/whats-new/2014/04/03/you-can-now-use-oracle-goldengate-with-amazon-rds-for-oracle/

Oracle Database on EC2 HA environment

Oracle Data Guard can be used to set up one or several slave databases which will be the foundation of a highly available environment. It maintains the standby databases as transaction- consistent copies of the primary database.  These instances can be placed in several availability zones.Then, if the production database becomes unavailable because of a planned or an unplanned outage of this instance or of the full availability zone, Data Guard can switch any standby database to the production role, minimizing the downtime associated with the outage.  It has three protection modes allowing the customers to maximize protection, availability or performance. The Active Data Guard module enables read-only access to the standby databases, thereby allowing customers to run read queries and reports on the standby instances, and to perform the backups from a standby instance.

You can have zero data loss by using the appropriate data protection mode:

http://docs.oracle.com/cd/B28359_01/server.111/b28294/protection.htm#CHDEDGIF

AWS Direct Connect active active with failover

A common question is: "Can use one direct connect connection as active active but also as failover?"

• Yes, Active/Active(BGPmultipath).Network traffic is load balanced across both connections. If one connection becomes unavailable, all traffic is routed through the other. This is the default configuration. 

Oracle WebLogic clustering

Active/active high availability with Oracle Weblogic on AWS EC2 can be done with Oracle WebLogic Server clustering.  You must use unicast as multicast is not supported on AWS.

AWS Four DR scenarios

There are four DR scenarios that highlight usage of AWS in a DR and a 'HA-lite' situation:

•  Backup and Restore - For systems running on AWS, customers also back up into Amazon S3. Snapshots of Elastic Block Store (EBS) volumes and backups of Amazon RDS are stored in Amazon S3. Alternatively, you can copy files directly into Amazon S3, or you can choose to create backup files and copy them to Amazon S3.
• Pilot Light for Simple Recovery into AWS - This scenario is similar to a Backup and Restore scenario, however, you must ensure that you have the most critical core elements of your system already configured and running in AWS (the pilot light). When the time comes for recovery, you would then rapidly provision a full scale production environment around the critical core. The database data would be replicated to S3. You would typically have some pre-configured servers bundled as Amazon Machine Images (AMIs), which are ready to be started up at a moment’s notice.  These servers could be EC2 instances that have been stopped.
• Warm Standby Solution - A warm standby solution extends the pilot light elements and preparation. It further decreases the recovery time because in this case, some services are always running. By identifying your business-critical systems, you would fully duplicate these systems on in another AWS zone or region and have them always on.  This would insure that the EC2 capacity is available in a disaster.
•  Active-Active Solution - A multi-site solution runs in another AZ or zone in an active-active configuration. The data replication method that you employ will be determined by the recovery point (RPO) you choose.