Using Relational Database Service (RDS) with SQL Server on
Amazon Web Services (AWS)
Are you thinking of using AWS RDS? If the answer is yes or
maybe, then some research is required to gain an understanding of the
constraints of the environment.
First, be prepared to learn a new vocabulary, as there are many
acronyms. Some you will want to learn from a database perspective are
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EC2
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Elastic Compute Cloud
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AZ
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Amazon Availability Zones
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S3
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Simple storage service
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EBS
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Elastic Block Storage
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VPC
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Virtual Private Cloud
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IAM
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Identity Access Management
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Here are some constraints to consider:
There is a limit of 30 databases per instance
Importing data with blobs requires all of them to be able to
fit into memory, as writing to the temp directory is prevented. SQL Server will
often write to the temp directory if there is not enough memory available to
hold the blob during an import
Small tables can be done through the import/export wizard
Larger tables and blob data should be performed through the
BCP utility
Resizing an instance up or down in CPU and memory may cause
a 2 second up to a five minute delay while it fails over if you are using a Mutli-AZ
Changing the storage type will cause the DBA to have to
rebuild the databases, i.e. recreate the database and then import the data again
Point in time recovery, will create a new instance and not
over write the current one. The DBA will need to rename the existing and the
new one to swap places, or extract the data and import it back into the
existing database.
Taking a snapshot freezes database I/O, so be alert as this
may cause transactions and connections to momentarily hang up to 10 seconds
Terminating an instance, make a final backup if you have any
doubt you might need to get the data back at a later date
Amazon provides very detailed documentation
Licensing everyone’s favorite area:
Beware that there are minimums with respect to how many
license you will need to have, if you’re going with the bring your own license
model.
Migrating to RDS for SQL Server
The Appendix the most interesting information lives here for
the DBA
