MongoDB Updated C100DBA Exam Questions and Answers by shiloh

connections.totalCreated is a cumulative count of incoming connections created during the lifetime of the running MongoDB server process. It includes connections that are still open as well as connections that have already closed. That is why the example can show totalCreated: 5 while current: 4: five connections have been created since the process started, but only four remain current. Option A is incorrect because the counter is not limited to closed connections. Option C corresponds more closely to connections.current, which reports presently existing incoming client connections. Option B is imprecise because “since the server was set up” could imply the lifetime of the installation or deployment across restarts, whereas server-status counters generally reflect the current process lifetime. Tracking totalCreated alongside current, active, and connection-pool behavior helps administrators identify excessive connection churn, poorly configured client pools, or bursts of new connections. The most accurate interpretation among the choices is therefore the number of connections created since the server process was started, making D correct.

Study Guide reference/topic:Performance Monitoring and Tuning - serverStatus, connection metrics, and cumulative connection counters.

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Sharding is MongoDB ' s horizontal-scaling mechanism: it partitions a collection ' s data across multiple shards so a deployment can scale storage capacity and distribute query or write workload beyond the limits of one server. That directly supports deployments with very large datasets and high-throughput operations, making C correct. MongoDB also supports zone sharding, which associates ranges of shard-key values with selected shards. Zones can be used to keep particular data near a geographical region, satisfy locality requirements, or map data ranges to hardware tiers, so A is also correct. Option B overstates what sharding itself provides; cross-region consistency behavior depends on replication topology, read/write concerns, latency, and application design rather than simply enabling sharding. Option D describes a deployment that already fits comfortably in memory and meets performance goals, so sharding may add unnecessary operational complexity. Option E primarily describes replication: replica sets maintain redundant copies, provide elections, and improve availability. Production shards are themselves normally replica sets, but redundancy is a replication function rather than the defining purpose of sharding. Therefore the two functions represented here are geographic zone distribution and horizontal scale: A and C.

Study Guide reference/topic:Sharding Strategies and Scalable Deployments - horizontal scaling, large datasets, throughput, shard keys, and zone sharding.