Direct Connect and Storage Gateway for migrating Oracle databases to AWS

You can use AWS Direct Connect instead of establishing a VPN connection over the Internet to your Amazon VPC, avoiding the need to utilize VPN hardware that frequently can’t support data transfer rates above 4 Gbps. Direct Connect is sometimes not considered because it involves a cross connect to an AWS Direct Connect. If you are already using a AWS Direct Connect partner you can be up and running quickly. There is no up front cost for Direct Connect and you can cancel at any time (such as after you do your initial data migration).

Another option Storage Gateway costs about $125 a month and the first 60 days is free.  300 Mbps can transfer 4 TB to S3 using storage gateway a day.  This requires you to install the AWS Storage Gateway at your facilities but is also completely on demand and can be canceled after your large data migration. 

Oracle RAC on AWS

Oracle Real Application Clusters (RAC) is not natively supported on AWS. The word natively is used because it is possible to run Oracle RAC in an AWS Direct Connect facility http://aws.amazon.com/directconnect/.

There are a number of options when migrating an Oracle RAC database to AWS.  The option you use depends upon the reason RAC is being used.  For HA and fail over, AWS offers multi-AZ capabilities which can provide the same level of service.  For very large databases that require high transaction through put that can not be achieved on a single instance database, Direct Connect would be the solution.  Details on these options are as follows:
1. RDS with multi-AZ :  Oracle RDS is the managed database service from AWS.  Oracle RDS has builtin multi-AZ capabilities.  Because RDS is a managed service, AWS takes care of installation, configuration and management of the secondary database, the replication between AZs, and the fail over and fail back of the database instance.
2. EC2 with multi-AZ :  Running on EC2 requires the customer or partner to install, configure, manage, and take care of the replication.    Oracle Data Guard or GoldenGate can be used for replication.
3. Direct Connect : The AWS partner Datapipe runs RAC in a managed service model using Direct Connect.

Note: Remember that AWS RDS only supports databases up to 6 TB in size. Note this number changed to 6 TB in June 2015 after being 2 TB. https://aws.amazon.com/about-aws/whats-new/2015/06/amazon-rds-increases-storage-limits-to-6TB-for-piops-and-gp2/. Check the whats new web page for any updates related to Oracle on RDS.

Note:  The reason Oracle Real Application Clusters (RAC) is not supported on AWS is:
1. Multicast is not supported on the AWS network. An overlay network is possible on AWS: http://cloudconclave.blogspot.com/2013/06/overlay-networks-on-aws.html
2. AWS EBS is not a shared disk / clustered file system.
So, even if you use a solution such as Amazon EFS, GlusterFS, Zadara, SoftNAS, or custom NFS for shared disk you can not use RAC on AWS as you need multicast support.  More on Amazon Elastic File System (EFS): https://aws.amazon.com/blogs/aws/amazon-elastic-file-system-shared-file-storage-for-amazon-ec2/ 

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 VLDB on AWS

As enterprise began to move to the cloud, the question of running very large Oracle databases on AWS is coming up.  Of course, the definition of a what is a VLDB varies by industry, size of company, and personal opinion.   For our discussion, let's say it is a 10's of TB database.  In this case, most Oracle databases of this size will be running on Oracle RAC.   Currently, Oracle RAC is not supported on AWS.

A method to get around the lack of support for RAC in AWS is running the application on EC2, and Oracle RAC in a co-location facility or customer data center. AWS Direct Connect allows establishing private connectivity between AWS and data center/co location or customer data center to achieve the speed required. Datapipe is one AWS hosting provider partner that has done this: 

http://www.slideshare.net/AmazonWebServices/aws-partner-presentation-datapipe-deploying-hybrid-it-aws-summit-2012-nyc