Synchronous replication

Definition

Synchronous replication is a data management technique where data is copied to a secondary storage location at the same time it is written to the primary storage. This process ensures that both the primary and secondary data sources remain consistent, offering high data availability and protection against data loss. It plays a critical role in strategies for data fragmentation and replication, ensuring that transactions are mirrored in real-time across distributed systems.

5 Must Know Facts For Your Next Test

1. Synchronous replication can introduce latency in write operations since data must be written to both primary and secondary locations before confirmation is sent to the application.
2. It is often used in mission-critical applications where data integrity and immediate consistency are essential, such as financial systems or healthcare databases.
3. While synchronous replication enhances data reliability, it can require more network bandwidth and may impact overall system performance due to the need for immediate acknowledgment of writes.
4. In environments with geographic data distribution, synchronous replication can be challenging due to network latency issues that may arise over long distances.
5. Many database management systems offer built-in support for synchronous replication, allowing users to configure it according to their specific needs for resilience and performance.

Review Questions

• How does synchronous replication differ from asynchronous replication in terms of data consistency and system performance?
  • Synchronous replication ensures that data is written to both primary and secondary locations simultaneously, maintaining immediate consistency between the two. In contrast, asynchronous replication allows changes to be copied to the secondary location with a delay, which can lead to temporary inconsistencies. While synchronous replication provides stronger guarantees regarding data integrity, it may introduce latency in write operations due to the requirement of confirming writes to both locations before completion.
• Discuss the advantages and disadvantages of using synchronous replication for database systems that require high availability.
  • Synchronous replication offers significant advantages for systems that need high availability, such as immediate consistency and protection against data loss. However, it can also lead to increased write latency and potential performance bottlenecks, especially in geographically distributed environments. Additionally, the requirement for real-time acknowledgment of writes can demand more network resources, making it less optimal in scenarios where speed is prioritized over data integrity.
• Evaluate how implementing synchronous replication could impact disaster recovery strategies in an organization.
  • Implementing synchronous replication can greatly enhance an organization's disaster recovery strategy by ensuring that a real-time copy of critical data is always available at a secondary site. This readiness minimizes downtime during incidents since both primary and secondary databases are synchronized. However, organizations must also consider the potential challenges, such as increased complexity in setup and maintenance costs. Moreover, if network disruptions occur during heavy write operations, they may hinder performance or lead to operational delays that could counteract some benefits of having synchronized backups.

Related terms

asynchronous replication:

A method of data replication where changes made to the primary storage are copied to the secondary storage with some delay, leading to potential inconsistencies between the two copies.

data consistency: The property that ensures that a database remains accurate and reliable, with all transactions reflecting the same state across all data copies.

high availability: A system design approach aimed at ensuring a certain level of operational performance, typically by minimizing downtime and maximizing uptime through redundancy.