Exam 350-901 topic 1 question 238 discussion

Actual exam question from Cisco's 350-901

Question #: 238
Topic #: 1

Two Elasticsearch database servers use bidirectional asynchronous data replication. Both servers accept writes from clients. The design must meet these requirements:
• The cluster survives if a fault occurs that causes the network connection to go down between nodes.
• The data remains consistent if communication between nodes fails.
• The data is spread evenly across all nodes in the cluster.

Which design approach must be used to meet the requirements?

A. Set the initial voting configuration to force a specific node as the master.
B. Set the minimum_master_nodes to 2 in the configuration.
C. Scale the master nodes down to a single node.
D. Add a third cluster node to provide majority votes.

Show Suggested Answer

Suggested Answer: D 🗳️

by [deleted] at Jan. 12, 2023, 1:34 p.m.

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ldlpi

Highly Voted 1 year, 2 months ago

Selected Answer: D

IMO, to avoid SPLIT BRAIN scenario, we will need 3 servers minimum

upvoted 7 times

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kati2k22cz

Most Recent 7 months, 1 week ago

Selected Answer: B

chatgpt version: Based on the requirements listed, the design approach that must be used to meet the requirements is: B. Set the minimum_master_nodes to 2 in the configuration. Setting the minimum_master_nodes to 2 ensures that in the event of a network partition, the cluster will not form a split brain scenario, which can lead to data inconsistencies and potential data loss. This setting ensures that there is a majority of nodes required to form a cluster. In case of a network issue or failure, if one set of nodes can't communicate with the other set, it won't form a separate cluster, ensuring data consistency and cluster survivability. Other options do not directly address the requirements stated, and some could even lead to potential data inconsistencies or failure in meeting the specified design goals.

upvoted 1 times

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whipmuffin

1 year ago

Selected Answer: D

To meet the requirements of the design approach, you need to add a third cluster node to provide majority votes. There should normally be an odd number of master-eligible nodes in a cluster. If there is an even number, Elasticsearch leaves one of them out of the voting configuration to ensure that it has an odd size. This omission does not decrease the failure-tolerance of the cluster¹.

upvoted 2 times

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[Removed]

1 year, 4 months ago

Selected Answer: B

Pretty sure it's B.

upvoted 2 times

lancejack2021

1 year, 1 month ago

According to this the minimum_master_nodes setting was deprecated in v7 released in 2019: https://www.elastic.co/blog/a-new-era-for-cluster-coordination-in-elasticsearch

upvoted 1 times

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