In a highly available MongoDB setup, what is the primary member responsible for?

In a highly available MongoDB setup, the primary member plays a crucial role by being responsible for handling read and write operations. This member is integral to the functioning of the replica set, as it ensures that all client applications connect to it for their data operations.

When a client requests to write data, it sends that request to the primary, which writes the data to its own dataset and then replicates this change to the secondary members for redundancy and failure recovery. Additionally, the primary member is the only one that can perform write operations in order to maintain consistency and prevent conflicts that could arise if multiple members are allowed to write simultaneously.

The other responsibilities in a MongoDB setup, such as data synchronization, backup and recovery, and managing user permissions, are important aspects of database management but are typically handled by the system collectively and do not fall under the specific purview of the primary member alone. Thus, the primary member's role as the handler of read and write operations is critical for the overall performance and reliability of the database in a highly available MongoDB environment.