Administering Windows Server Hybrid Core Infrastructure (AZ-800) Practice

When implementing Storage Replica, what is the round-trip latency threshold above which asynchronous, rather than synchronous, replication should be used?

1. 1 ms

2. 5 ms

3. 20 ms

4. 50 ms

The correct answer is: 5 ms

When implementing Storage Replica, the recommended round-trip latency threshold for determining whether to use asynchronous rather than synchronous replication is 5 milliseconds. In a synchronous replication setup, data must be written to both the source and destination before acknowledging the write to the client. This mechanism requires low latency to ensure that performance remains acceptable, as higher latencies can significantly affect application responsiveness and lead to performance degradation. If latency exceeds 5 milliseconds, the added time for writing to the secondary site introduces potential delays that can impact the overall system performance. Thus, in scenarios where round-trip latency is greater than this threshold, asynchronous replication becomes the preferred solution. This method allows for data to be written to the primary site without waiting for confirmation from the secondary site, which can be beneficial for maintaining application performance over longer distances or in environments where latency is inherently higher. Understanding this threshold helps in planning a disaster recovery strategy and ensures that the replication method chosen aligns with the performance requirements of the applications involved.