 |
|
High Availability Consulting Services
TruTek Consulting services can help your organization implement and learn how to properly administer Oracle products that can allow high availability of the database.The Maximum Availability Architecture incorporates redundant services at the application server and database tier. Disaster Recovery services for the database use DataGuard.
TruTek Consulting can help you implement the following high availability services:
- Real Application Clusters
- DataGuard
- Flashback Query
These are the main components of Oracle’s solution for unplanned downtime.
Non-Oracle solutions for unplanned downtime include replication and storage array failover. Each method has its advantages as described in the following table:
Implement Flashback Query
- Allows users to see a consistent read only view of the database at a point in the past
- Leverages System Managed Undo functionality
- Undo information is kept for a specified retention interval at system level
- Enabled at a session level
Enable Flashback Database
Flashback Database removes the need to re-create the primary database after a failover. Flashback Database is similar to conventional point-in-time recovery in its effects, enabling you to return a database to its state at a time in the recent past. Flashback Database is faster than point-in-time recovery, because it does not require restoring datafiles from backup or the extensive application of redo data. You can enable Flashback Database on the primary database, the standby database, or both.
How Does the Flashback Query Work?
The Oracle database uses a version based read consistency mechanism by saving an image of the data prior to making any modifications. These changes are stored in the undo tablespace (or RollbackSegments). Should the user later decide not to commit the transaction or if the operation was not successful, Oracle uses the data saved in the undo tablespace to recreate the original data. The undo data is also used to generate a snapshot of data consistent to a point in time when a query was started if another user has modified the underlying data. Flashback Query relies on the same mechanism to construct an image of the data as it existed at a time in the past. The undo data, therefore, must be available in order for a Flashback Query to be successful. Oracle9i’s Automatic Undo Management feature allows administrators to specify how long they wish to retain the undo data using the UNDO_RETENTION initialization parameter. By using this parameter and sizing the undo tablespace appropriately, DBAs can control how far back a Flashback Query can go.
Implement DataGuard
Example pricing for a recent DataGuard (non-Active) implementation:
Qty |
Description |
List Each |
Ext. List |
Disc. |
Cost Each |
Extended Cost |
1 |
Implement DataGuard fixed price |
$7,500.00 |
$7,500.00 |
$7,500.00 |
$7,500.00 |
|
1 |
Implement OEM - TEST and PROD - mandatory |
$3,000.00 |
$3,000.00 |
$3,000.00 |
$3,000.00 |
|
1 |
Train staff on Data Guard failover - optional |
$3,000.00 |
$3,000.00 |
$3,000.00 |
$3,000.00 |
|
1 |
Setup monthly failover test - optional |
$3,000.00 |
$3,000.00 |
$3,000.00 |
$3,000.00 |
|
Total List |
$16,500.00 |
Subtotal |
$16,500.00 |
Implement Active DataGuard
Eliminate Idle Redundancy of Your Standby Database
Oracle Active Data Guard—an option for Oracle Database 11g Enterprise Edition—enhances quality of service by offloading resource-intensive activities from a production database to one or more synchronized standby databases. Oracle Active Data Guard enables read-only access to a physical standby database for queries, sorting, reporting, Web-based access, and so on, while continuously applying changes received from the production database. Oracle Active Data Guard also enables the use of fast incremental backups when offloading backups to a standby database and can provide additional benefits of high availability and disaster protection against planned or unplanned outages at the production site.
- Increase performance - Offload unpredictable workloads to an up-to-date replica of the production database
- Simplify operations - Eliminate management complexity that accompanies traditional replication solutions
- Eliminate compromise - The reporting replica is up to date and online at all times, which is not possible with traditional storage mirroring technology
- Reduce cost - An Oracle Active Data Guard physical standby database can also provide disaster recovery and/or serve as a test database - no additional storage or servers required
Summary of Data Guard Benefits
- Disaster recovery, data protection, and high availability
Data Guard provides an efficient and comprehensive disaster recovery and high availability solution. Easy-to-manage switchover and failover capabilities allow role reversals between primary and standby databases, minimizing the downtime of the primary database for planned and unplanned outages.
- Complete data protection
With standby databases, Data Guard guarantees no data loss, even in the face of unforeseen disasters. A standby database provides a safeguard against data corruption and user errors. Storage level physical corruptions on the primary database do not propagate to the standby database. Similarly, logical corruptions or user errors that cause the primary database to be permanently damaged can be resolved. Finally, the redo data is validated when it is applied to the standby database.
- Active DataGuard requires additional licensing
The standby database tables that are updated with redo data received from the primary database can be used for other tasks such as backups, reporting, summations, and queries, thereby reducing the primary database workload necessary to perform these tasks, saving valuable CPU and I/O cycles. With a logical standby database, users can perform normal data manipulation on tables in schemas that are not updated from the primary database. A logical standby database can remain open while the tables are updated from the primary database, and the tables are simultaneously available for read-only access. Finally, additional indexes and materialized views can be created on the maintained tables for better query performance and to suit specific business requirements.
- Flexibility in data protection to balance availability against performance requirements
Oracle Data Guard offers maximum protection, maximum availability, and maximum performance modes to help enterprises balance data availability against system performance requirements.
- Automatic gap detection and resolution
If connectivity is lost between the primary and one or more standby databases (for example, due to network problems), redo data being generated on the primary database cannot be sent to those standby databases. Once a connection is reestablished, the missing archived redo log files (referred to as a gap) are automatically detected by Data Guard, which then automatically transmits the missing archived redo log files to the standby databases. The standby databases are synchronized with the primary database, without manual intervention by the DBA.
- Centralized and simple management
The Data Guard broker provides a graphical user interface and a command-line interface to automate management and operational tasks across multiple databases in a Data Guard configuration. The broker also monitors all of the systems within a single Data Guard configuration.
- Integration with Oracle Database
Data Guard is a feature of Oracle Database Enterprise Edition and does not require separate installation.
Implement Real Application Clusters
Example of RAC costs
| Shared Disk | $40,000 | |
| Oracle software | $200,000 | (depends on licensing method) |
| 4 2-CPU nodes | $40,000 | |
| 2TB storage | $80,000 | |
| 2 switches | $20,000 | |
| Support and services | $100,000 | |
| Total | $480,000 |
|
||||||
|
