Exam 350-901 topic 1 question 174 discussion

Actual exam question from Cisco's 350-901

Question #: 174
Topic #: 1

Refer to the exhibit. A Docker swarm cluster is configured to load balance services across data centers in three different geographical regions: west, central, and east. The cluster has three manager nodes and three worker nodes. A new service named cisco_devnet is being deployed. The service has these design requirements:
✑ All containers must be hosted only on nodes in the central region.
✑ The service must run only on nodes that are ineligible for the manager role.
Which approach fulfills the requirements?

A. Use placement constraints to control nodes to which the service can be assigned.
B. Create the service manually in the central region and set replicas to 0.
C. Enable the control flag in the containers of the west and east regions to prevent the service from starting.
D. Create a second swarm cluster that is hosted only in the central region.

Show Suggested Answer

Suggested Answer: A 🗳️

by testadviser at March 10, 2022, 12:24 p.m.

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Teringzooi

7 months, 3 weeks ago

Selected Answer: A

Answer A seems to be correct. Placement preferences let you apply an arbitrary label with a range of values to each node, and spread your service’s tasks across those nodes using an algorithm. Currently, the only supported algorithm is spread, which tries to place them evenly. For instance, if you label each node with a label rack which has a value from 1-10, then specify a placement preference keyed on rack, then service tasks are placed as evenly as possible across all nodes with the label rack, after taking other placement constraints, placement preferences, and other node-specific limitations into account. https://docs.docker.com/engine/swarm/services/#control-service-placement

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testadviser

1 year, 2 months ago

Option "A" seems correct: https://docs.docker.com/engine/swarm/services/#control-service-placement

upvoted 4 times

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