Which of the following features ensures even distribution of traffic to Amazon EC2 instances in multiple
Availability Zones registered with a load balancer?
A.
Elastic Load Balancing request routing
B.
An Amazon Route 53 weighted routing policy
C.
Elastic Load Balancing cross-zone load balancing
D.
An Amazon Route 53 latency routing policy
Explanation:
http://aws.amazon.com/elasticloadbalancing/
C
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If cross-zone load balancing is disabled, the load balancer node selects the instance from the same Availability Zone that it is in. If cross-zone load balancing is enabled, the load balancer node selects the instance regardless of Availability Zone.
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/how-elb-works.html#request-routing
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C
To distribute traffic evenly across all back-end instances, regardless of the Availability Zone, enable cross-zone load balancing on your load balancer.
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c
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C
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/enable-disable-crosszone-lb.html
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I have the same idea. A
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Answer is C
Cross-zone load balancing is always enabled for an Application Load Balancer and is disabled by default for a Classic Load Balancer. If cross-zone load balancing is enabled, the load balancer distributes traffic evenly across all registered instances in all enabled Availability Zones. If cross-zone load balancing is disabled, the load balancer distributes traffic evenly across all enabled Availability Zones. For example, suppose that you have 10 instances in Availability Zone us-west-2a and 2 instances in us-west-2b. If cross-zone load balancing is disabled, the requests are distributed evenly between us-west-2a and us-west-2b. As a result, the 2 instances in us-west-2b serve the same amount of traffic as the 10 instances in us-west-2a. However, if cross-zone load balancing is enabled, the load balancer distributes incoming requests evenly across all 12 instances.
http://docs.aws.amazon.com/elasticloadbalancing/latest/userguide/how-elastic-load-balancing-works.html
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C
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C
Cross-zone load balancing enabled – Spread traffic per instances;
Cross-zone load balancing disabled – Spread traffic per AZ;
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If this the case, A is most appropriate answer. As question is talking about “even distribution of traffic to Amazon EC2 instances”
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yes Vicky is right
Answer = A
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A
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http://docs.aws.amazon.com/elasticloadbalancing/latest/userguide/how-elastic-load-balancing-works.html#availability-zones
Request Routing – Routing Algorithm
With a Classic Load Balancer, the load balancer node that receives the request selects a registered instance using the round robin routing algorithm for TCP listeners and the least outstanding requests routing algorithm for HTTP and HTTPS listeners.
If the “Traffic” in the question means TCP traffic, A is correct.
If the “Traffic” means HTTP and/or HTTPS traffic, and some HTTP/HTTPs requests take longer to respond than others, the traffic will not be evenly distributed.
So C is a safe answer.
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C is the right answer.
See http://docs.aws.amazon.com/elasticloadbalancing/latest/userguide/how-elastic-load-balancing-works.html#availability-zones
Cross-zone load balancing is always enabled for an Application Load Balancer and is disabled by default for a Classic Load Balancer. If cross-zone load balancing is enabled, the load balancer distributes traffic evenly across all registered instances in all enabled Availability Zones. If cross-zone load balancing is disabled, the load balancer distributes traffic evenly across all enabled Availability Zones.
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yes I agree
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C
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C is the perfect answer
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C = Correct Answer as explained by Amazon below:
If cross-zone load balancing is enabled, the load balancer distributes traffic evenly across all registered instances in all enabled Availability Zones. If cross-zone load balancing is disabled, the load balancer distributes traffic evenly across all enabled Availability Zones. For example, suppose that you have 10 instances in Availability Zone us-west-2a and 2 instances in us-west-2b. If cross-zone load balancing is disabled, the requests are distributed evenly between us-west-2a and us-west-2b. As a result, the 2 instances in us-west-2b serve the same amount of traffic as the 10 instances in us-west-2a. However, if cross-zone load balancing is enabled, the load balancer distributes incoming requests evenly across all 12 instances.
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Per the AWS document,C is correct .
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