Advantages, Disadvantages and Steps to migrate Oracle Database to Amazon RDS

1. Amazon RDS
Migrate Oracle Database to
Guatemala, September 2017

2. Why migrate to DBaaS?
Cost
Database management is expensive.
Moving to DBaaS reduces management
cost, moving to open source engines can
reduce costs by 90% or more.
Risks
Proprietary databases are risky.
Availability, scalability, malwares.

3. Where do DBAs spend their time?

4. Cloud Computing Services

5. Cloud Providers?

7. Amazon Relational Database Service (RDS)
• Database as a Service
• Fully managed database service
• Automated hardware provisioning, patching,
backup/restore, scaling
• High availability with RDS Multi-AZ, Auto-
Failover
 99.95% SLA for Multi-AZ deployments
• Database monitoring and alerts
• Security

8. Amazon RDS Engines

9. The Dilemma (RDS vs. EC2)
• RDS vs. EC2
• Didn’t like the idea of RDS
• Too restrictive/loss of control
• No direct access to the box
• “It’s doing my job”
• DBAs conducted a full review
with an open mind

10. The Dilemma (RDS vs. EC2)
EC2
• Pros
Flexibility w/ full access
Access to the Oracle utilities
(Dataguard, RMAN, etc.)
Similar to the way it’s managed today
• Cons
Self-deployed
High administrative overhead (all
tasks manual - self installation,
patching, backups, etc.)
RDS
• Pros
Managed Service = reduced overhead
(easy deployment, automated
patching and backups, etc.)
Multi-AZ option for HA
Parameter and Option groups
Flexible license model with BYOL
option
• Cons
Don’t have access to all the Oracle
utilities

11. Migrate Oracle Database to
Amazon RDS

12. Options to Migrate to RDS
• Oracle SQL Developer
Small Databases
• Oracle Data Pump
Move large Databases
• Oracle Export/Import Utilities
• Oracle SQL*Loader
• Oracle Golden Gate
• Migration and replication
• RMAN ? Dataguard Not possible
• Amazon Data Migration Services (DMS)

13. Migration Time using Oracle Data Pump
Export
Upload to
RDS
Import
Switch
Applications
• How much downtime is acceptable?
• Depending on the size of the database, the time increases
• Sometimes upload the export file is a problem
• You can use an EC2 instance to mitigate the problem
Create a Standby Database on EC2
Reduce problems to upload export file

14. … Using a EC2 pivot instance
• Standby Database on EC2
• Replication in real time
• Upload Export file from AWS
Network
• Reduce time to upload export
file

15. Migrate Process …
Step 1: Grant privileges to user on source database
Step 2: Stop all database transactions
Step 3: Check Dataguard synchronization
Step 4: Open Standby Database
Step 5: Use Export Data Pump or DBMS_DATAPUMP to create a dump
file from Database on EC2
$ expdp user1 DUMPFILE=tab1.dmp DIRECTORY=DATA_PUMP_DIR full=y

16. Step 6: Create a database link to the target DB instance (RDS) from the
Database on EC2
Migrate Process …
SQL>
create database link to_rds connect to USER2 identified by user2pwd using
'(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=<dns or ip address of remote
db>)(PORT=<listener port>))(CONNECT_DATA=(SID=<remoteSID>)))';

17. Migrate Process …
Step 7: Use DBMS_FILE_TRANSFER to copy the exported dump file to
the Amazon RDS instance from the Database on EC2.
SQL>
BEGIN
DBMS_FILE_TRANSFER.PUT_FILE(
source_directory_object => 'DATA_PUMP_DIR',
source_file_name => 'tab1.dmp',
destination_directory_object => 'DATA_PUMP_DIR',
destination_file_name => 'tab1_copied.dmp',
destination_database => 'to_rds'
);
END;
/

18. Step 8: Import the dump file into a database on the Amazon RDS
instance from the Database on EC2.
Migrate Process …
$ impdp rds_user@to_rds DUMPFILE=tab1_copied.dmp DIRECTORY=DATA_PUMP_DIR
full=y EXCLUDE=SCHEMA:"IN ('ORDSYS',
'ORDPLUGINS','SI_INFORMTN_SCHEMA','ORDDATA','MDSYS')"

19. Step 9: Clean up dump file from RDS instance.
Migrate Process …
SQL> select * from table(RDSADMIN.RDS_FILE_UTIL.LISTDIR('DATA_PUMP_DIR'))
order by mtime;
SQL> exec utl_file.fremove('DATA_PUMP_DIR','tab1_copied.dmp');

20. Thank you!
Jesús Guzmán
Blog: https://susguzman.wordpress.com/
Email: susguzman@gmail.com, jguzman@datum.com.gt
http://www.datum.com.gt/