DATABASE FUNDAMENTALS
BASICS OF BIG DATA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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TRUE
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False
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Either A or B
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None of the above
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Detailed explanation-1: -A snitch determines which datacenters and racks nodes belong to. A snitch determines which datacenters and racks nodes belong to. They inform Cassandra about the network topology so that requests are routed efficiently and allows Cassandra to distribute replicas by grouping machines into datacenters and racks.
Detailed explanation-2: -1. Which of the following is true about Apache Cassandra? Explanation: Apache Cassandra is a free and open-source, distributed, wide column store.
Detailed explanation-3: -Gossip is used to identify the state of machines (are they in the cluster, up/down/joining/leaving). The snitches help map ownership to an actual machine, and route queries (given these 10 nodes in the cluster, which of the 10 own the data for a given key).
Detailed explanation-4: -Monitors the performance of reads from the various replicas and chooses the best replica based on this history. By default, all snitches also use a dynamic snitch layer that monitors read latency and, when possible, routes requests away from poorly-performing nodes.
Detailed explanation-5: -Dynamic snitching The dynamic snitch monitor read latencies to avoid reading from hosts that have slowed down. The dynamic snitch is configured with the following properties on cassandra.