What Does Synchronous Replication Mean?
Synchronous replication is a process for simultaneous updates of multiple repositories often used with a storage area network or wireless network or other segmented system. In synchronous replication, the technology is writing data to two systems at once, rather than one at a time.
Synchronous replication is often used for disaster recovery, or for specific business goals and objectives dependent on the availability of data.
Techopedia Explains Synchronous Replication
The idea of synchronous replication is an example of key redundancies used to make systems efficient. Having data available in redundant zones makes that data more resilient if anything were to happen to the system.
In synchronous replication, the system is updating two or more of these redundant repositories at a time – or in some cases, updating a home base repository and an active repository to stay exactly the same in real time. With asynchronous replication, there may be discrepancies in real time, because the system isn't writing to both places at once.
Synchronous replication does require more resources in general, and may introduce latency to an application, but in many cases, it's worth it in order to have the real-time data consistency.