A customer has a web application that uses cookie Based sessions to track logged in users It Is deployed on
AWS using ELB and Auto Scaling The customer observes that when load increases. Auto Scaling launches new
Instances but the load on the easting Instances does not decrease, causing all existing users to have a sluggish
experience.
Which two answer choices independently describe a behavior that could be the cause of the sluggish user
experience?
Choose 2 answers
A.
ELB’s normal behavior sends requests from the same user to the same backend instance
B.
ELB’s behavior when sticky sessions are enabled causes ELB to send requests in the same session to the
same backend instance
C.
A faulty browser is not honoring the TTL of the ELB DNS name.
D.
The web application uses long polling such as comet or websockets. Thereby keeping a connection open to
a web server tor a long time
E.
The web application uses long polling such as comet or websockets. Thereby keeping a connection open to a
web server for a long time.
can someone help me with this one…. confusing
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/elb-sticky-sessions.html
AWS ELB doesn’t support WebSockets on HTTP/HTTPS (Layer 7).
B.
ELB’s behavior when sticky sessions are enabled causes ELB to send requests in the same session to the
same backend instance
This question needs to be fixed. The answers are not correct.
B, the existing load wouldn’t be redistributed if sticky sessions were configured.
I think it’s B & D (Choose 2 answers).
https://www.pubnub.com/blog/2014-12-01-http-long-polling/
@Chef: It’s between the web and app server, therfore not through the ELB
C. A faulty browser is not honoring the TTL of the ELB DNS name. –> If only one user is affected, this can be the reason, but not in this case, there is no load at all
A.
ELB’s normal behavior sends requests from the same user to the same backend instance –> no way, because B
B is correct.
Both D and E are identical which one to pick ??
B. D AND E are the same, so Answer is B AND (D OR E)
bd
B is the obvious choice
C is plausible based on lameness of this question, hear me out: We know that when the DNS TTL expires, the newly registered instances are known to client as they re-resolve – if the browser has problems, this could be the independent issue. Also, this was the only subject recently covered with AWS, there has been no mention of websockets(used for FB junk messages)
bd
ELB’s normal behavior sends requests from the same user to the same backend instance
(its not by default)
ELB’s behavior when sticky sessions are enabled causes ELB to send requests in the same session to the same backend
A faulty browser is not honoring the TTL of the ELB DNS name
(DNS TTL would only impact the ELB instances if scaled and not the EC2 instances to which the traffic is routed)
The web application uses long polling such as comet or websockets. Thereby keeping a connection open to a web server tor a long time
BD