Replication

What happens to the replica set if a majority of voting members are permanently lost?

When using 'readConcern: majority', what is the specific guarantee provided to the client?

What occurs when a replica set member experiences a 'rollback'?

Which command is used to check the current replication lag status on a secondary node?

Which THREE actions occur when a MongoDB secondary node performs an initial sync?

You are a DBA for a MongoDB replica set. A secondary node has been down for several days and is far behind the primary. The oplog on the primary has wrapped, and the secondary's last oplog entry is no longer present. What must you do to bring the secondary back into sync?

You are configuring a MongoDB replica set for a global application. You need to add a member that will never become primary and will be invisible to client applications. Which two steps must you take when adding this member? (Choose two.)

In a replica set, what is the 'oplog' and why is it important?

You are the DBA for a MongoDB 6.0 replica set with three voting members: rs0-primary (priority 2), rs0-secondary-1 (priority 1), and rs0-secondary-2 (priority 1). The primary fails and is unavailable for an extended period. You need to ensure that rs0-secondary-1 is elected as the new primary instead of rs0-secondary-2. Which action should you take before the primary fails?

When adding a new member to an existing replica set, what is the most common reason for the initial sync process to fail if the data set is extremely large?

How can you prevent a specific node from becoming a primary in a replica set?

In a three-node replica set with default write concerns, what occurs when the primary node experiences a network partition and cannot communicate with the majority of the set?

What is the result of setting the 'votes' configuration to 0 for a specific node in a replica set?

When a secondary node is lagging behind the primary, what is the most significant risk to the replica set if the lag time exceeds the length of the oplog?

Refer to the exhibit. If the primary node fails, which node is most likely to be elected the next primary based on optime?

What is the primary function of the oplog in a MongoDB replica set?

What is the primary purpose of an Arbiter in a MongoDB replica set?

A three-member replica set has default settings, and all three members are healthy. A DBA needs to perform an index build on the primary during business hours. Which concern should the DBA consider regarding replica set behavior?

A DBA is adding a new secondary to an existing replica set. The data set is 2 TB, and the network bandwidth between the new member and the primary is 100 Mbps. The DBA wants to minimize the impact on the primary during the initial sync. Which approach should the DBA take?

A DBA is troubleshooting a replica set where the secondary is consistently lagging behind the primary by several hours. The DBA notices that the secondary's optime is far behind the primary's optime, and the secondary's oplog window is only 1 hour. The primary has a heavy write workload. Which action should the DBA take to reduce the replication lag and prevent the secondary from falling off the oplog?

You are the DBA for a three-member MongoDB replica set. The primary becomes unreachable due to a network partition, and two secondaries remain in communication. After the election timeout, one secondary is elected primary. What is the required condition for a new primary to be elected?

You are a DBA for a MongoDB replica set. A developer asks you to explain what the oplog is and why it is important. What is the correct description?

A MongoDB DBA is investigating replication lag on a secondary member named rs0-2. The DBA runs rs.status() and notices that the 'optimeDate' of rs0-2 is several hours behind the primary's 'optimeDate'. The DBA wants to quickly determine the exact time difference. Which field in the rs.status() output should the DBA compare to calculate the replication lag?

In a three-node replica set with default write concern w:1, what happens to an unacknowledged write if the primary crashes immediately after receiving the write command but before replicating it to secondaries?

You are administering a MongoDB 6.0 replica set with three members: a primary and two secondaries. You need to perform a rolling maintenance on the secondaries, which involves restarting each secondary one at a time. Which two actions must you take to ensure that the replica set remains available for writes during the maintenance? (Choose two.)

Which member type in a MongoDB replica set is best suited for a geographically distant data center to provide read-only access without influencing elections?

Refer to the exhibit. What is the primary function of the node with _id 2 in this replica set?

Which THREE factors can significantly impact the time taken for a new primary election?