Comparison to Competition

Most Database professionals are familiar with two high availability solutions: Data Guard from Oracle, which is included in Oracle's Enterprise License, and Shareplex by Quest Software, which is sold as an add-on solution. Ixion's IxPropagator offers significant advantages over both these products:

• Faster performance
• Less chance of data loss
• Easier installation and use
• Improved performance replicating to a hot secondary site
• Simpler fail over and failback
• Lower total cost of ownership

Comparison to Data Guard

Oracle's data replication solution is called Data Guard (also known as Standby). The primary benefit of using Oracle Data Guard is that it comes with the Enterprise edition of Oracle and therefore can be utilized with no additional upfront licensing cost.

A typical Ixion customer, with a large Oracle environment, will have the license to Data Guard. However they will have chosen to use IxPropagator because of the many advantages it offers over the "free" product. IxPropagator gives them a much faster performing product with a much lower potential for data loss. Further, IxPropagator has a lower total cost of ownership, even with the upfront licensing fee - because of the ease of installation, configuration and on-going use. IxPropagator customers realize significant savings in ongoing Oracle support costs, not to mention the avoided cost of downtime resulting in lost revenue.

The main disadvantage of using Oracle Data Guard is that it is complicated to configure and administer, which ends up costing more in the long run in the form of consulting fees and support staff. Other disadvantages of Data Guard are that: 1) it is slower, and therefore the failover site will not be completely in sync with the primary site, 2) it relies on a single architecture that can result in a higher potential for data loss than the flexible approach of IxPropagator, 3) it has no easy failback mechanism, whereas IxPropagator can failback to the primary site quickly and easily, and 4) it is cumbersome and severely degrades performance if Logical Standby is used to achieve an open and available ("hot") failover site, whereas IxPropagator is easy to configure in this mode and has no effect on performance.

Key Advantages Over Data Guard

IxPropagator is much easier to install, configure, and maintain - you can be running IxPropagator much sooner and at much lower "setup" and maintenance cost down the road.

With Data Guard, most customers are running physical standby for performance reasons, but would like to be able to keep their secondary site open and available without the performance hit. Perhaps the biggest advantage of IxPropagator, which appeals to the broadest base of customers, is that IxPropagator allows you to do just that - keep a "hot" secondary site so you can off-load reporting and other read-only operations that would otherwise bog down performance of your primary system. This also has a big cost advantage because you save on Oracle licenses and you save on hardware utilization.

IxPropagator has much faster replication speeds. Ixion's customers to-date are large companies with very large Oracle environments that are dealing with heavy-volume OLTP applications. In order to minimize data loss, you need a product that can replicate data as fast as possible so there is a) nothing sitting in shared memory or b) no unapplied logs queued up, both of which result in lost data in an outage. Because of its unique architecture, IxPropagator can replicate data orders of magnitude faster than Data Guard, does not rely on shared memory, and will never "fall behind" in the data transmission.

With Data Guard, some operations on the primary database that improve performance of bulk operations results in data block corruption on the standby database. The corruption can occur at either the table or index level. Rebuilding indexes during a failover adds to the failover time and makes the failover process risky. If the corruption is at the table level, then the only option is to rebuild the database. Ixion's customers have had these very problems with Data Guard. These are not issues with IxPropagator.

The original version of IxPropagator has been out for several years now, although the apply engine has been refined significantly over the last two years. Before the end of the year Ixion customers will begin testing the latest version that will allow them to select from a variety of options with regard to data capture and compression methods. A customer's specific application needs will dictate whether they wish to use the trigger-based data capture architecture or the log-based architecture. The application architecture of IxPropagator will be different with respect to how the data is captured and transmitted depending on the option they choose. How data is applied to the secondary will not change. The apply engine (IxEngine) remains the fastest data transmission engine for Oracle that is commercially available.

Comparison to Shareplex

Shareplex is a high-performance replication tool with capability of replicating thousands of operations per second. IxPropagator, however, can outpace even Shareplex in replication speed. And the performance advantage of IxPropagator is even more pronounced across a slow network, when bandwidth is a challenge.

IxPropagator uses compression before transmission across the network and adheres to the read consistency model. However, with IxPropagator, no rows are moved until they are actually committed into the primary site. SharePlex moves data from the primary prior to commit and thus must also move the reverse operation (if possible) when the user performs a rollback. For example, if a user adds 100 rows to the primary system, these rows would not be moved by IxPropagator until the user commits them on the primary. SharePlex, on the other hand, would move the rows as the user makes the changes. If the user rolls back but at the same instance a network error occurs or a database failure occurs on the target host, the database would be in an inconsistent state at the target since the changes that SharePlex moved would be committed, even though the user rolled back. There is an operating mode available in Shareplex that utilizes "memory mapping files" and avoids the rollback issue described above, but the performance degradation of this operating mode is significant.

With regard to failover, this is done using a simple command line (or optional GUI) interface with IxPropagator. This is very quick and efficient compared to Shareplex, with no need to quiesce the database in order to start the application - simply verify that the Queues are cleared and failover. With Shareplex, however, the databases must be quiesced before startup. This can take awhile due to performing table analysis for "chained rows".

Ixion's experience has shown that every customer has unique needs when it comes to achieving high availability for volume-heavy applications that run in their large Oracle environments. IxPropagator provides three different data capture methods, and different levels of data compression (or no compression) to enable customers to tailor IxPropagator's replication functionality to their specific application architecture. The options available include a trigger-based data "push", a trigger-based data "pull", and a log-based data "push". Ixion's patented apply engine is used with all three options. The versatility of IxPropagator allows you to take greatest advantage of IxPropagator's performance options while at the same time minimizing the impact on your application performance. Shareplex does not offer this type of flexibility.

Ixion's experience has shown that some applications can utilize the trigger-based data capture method which will afford greater performance out of replication. Other applications, particularly table-intensive ERP applications like SAP, require the log-based data capture method. Ixion's unique application architecture allows for greater performance and less chance for data loss than Shareplex even when log-based data capture methods are necessary.

A key aspect of IxPropagator's architecture ensures that the chance of data loss during an unplanned outage is significantly less than with Shareplex. IxPropagator makes full use of all the recovery features available in Oracle during machine failures. Shareplex's default configuration continues to rely on the shared memory queue. There is an option available with Shareplex to write to memory-mapped files, but performance can drop significantly (20% or more) using this option.

Other key advantages continue to be the ease of installation and configuration and replication speed. Many companies are turned off from implementing data replication because of the significant start-up costs in terms of resources and time devoted to the effort. IxPropagator continues to be the "low-cost-of-entry" option both in direct and indirect costs. In addition, IxPropagator is very low maintenance, as Ixion support personnel can attest! Finally, IxPropagator remains the fastest data replication product on the market - significantly faster than Shareplex or Data Guard. Once customers see how easy it is to get started, how reliable it is once it's running, how fast it can actually replicate data, and how easy and reliable the failover and failback processes are, they become IxPropagator loyalists every time.

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