Search Rocket site

Debunking Business Continuity Myths: Part 2

Bruce Decker

Missed Part 1? Read it now.

Myth #2: Hardware Data Replication Is the Answer. While hardware replication technologies offer a semblance of data redundancy, they fall short in ensuring both physical and logical integrity. Suspending database updates during replication attempts to mitigate this, but it often leads to noticeable disruptions and compromises the desired Recovery Point Objective (RPO).

  • Physical vs. Logical Integrity: While suspending database updates during backups ensures physical data integrity by preventing file corruption, it doesn't guarantee logical integrity. For instance, if a batch update involves multiple records, suspending updates mid-transaction could result in logically incomplete data in the replicated image.
  • Transaction Boundaries: Applications utilizing defined transaction boundaries ensure logical integrity by ensuring related database updates occur together or not at all. However, applications lacking such boundaries risk logical corruption as each update is treated as a separate transaction.
  • Challenges in Achieving RPO: Suspending updates to maintain data consistency is impractical during business hours, making it challenging to achieve acceptable Recovery Point Objectives (RPOs) within the desired timeframes.
  • Database Commands and Best Practices: Most modern databases offer commands to suspend updates, but their practical implementation may not align with operational needs. Adhering to best practices, such as defining transaction boundaries and scheduling backups during low-activity periods, can help mitigate risks and ensure data integrity.

In summary, while replication technologies offer the promise of data redundancy, ensuring both physical and logical integrity requires careful consideration of transaction boundaries, operational constraints, and database commands. By understanding these nuances, businesses can optimize their backup strategies to meet both their recovery objectives and data integrity requirements.

Myth #3: Hardware Data Replication Alone Gives RPO. Relying solely on hardware replication for achieving low RPO objectives is wishful thinking. Despite their allure, these systems lack the awareness to choose the precise moment for replication, resulting in significant delays and rendering them ineffective for maintaining real-time data consistency.

To ensure that the replication system chooses the right moment, you must force a steady data state by forcing your database to suspend its updates. For most databases and snapshot systems, this results in a considerable “pause” up to minutes in duration. This is noticeable to users and may even cause the failure of processes. Because of this noticeable impact to users and processes, business usually limit the number of these replication events to just a few times per day at most. As a result, the RPO becomes measured in hours rather than the desired moments, rendering this approach, by itself, an ineffective strategy for low RPO.

Many businesses use virtual machine or disk replication thinking that it will provide a stable recovery point. Many use these tools without pausing the database. It will work some of the time but, keeping our engineering credo in mind, our business expects us to create a recovery process that cannot be made to fail.

Myth #4: With Replication, Who Needs Backups? The misconception that replication obviates the need for backups is dangerously misguided. Replication systems are vulnerable to undesired data state changes and can falter in the event of failures or network disruptions. Many businesses settle into a false sense of security based on a fundamental misunderstanding about the capabilities of a solution. As business owners, while we may not be technology experts, it falls to us to demand proof that our systems are recoverable. Overlooking backups in favor of replication jeopardizes a business's ability to recover from catastrophic events.

While cloning, snapshots, and disk replication serve as valuable components of a business continuity strategy, their efficacy hinges on a clear understanding of their limitations. Businesses must scrutinize their backup and recovery methods to ensure resilience in the face of adversity. A comprehensive approach, encompassing both backup and replication, is essential to safeguarding business operations and mitigating risk.

The myths surrounding business continuity underscore the need for informed decision-making and a holistic approach to resilience planning. By dispelling these misconceptions and embracing a proactive stance towards business continuity, organizations can navigate uncertainties with confidence and resilience.

If you’re ready to start your HA/DR journey or improve your current strategy, contact your Rocket salesperson or the Rocket partner who provides your solution or get a quote.