SQS COPY Flashcards
True or False: SQS messages cannot be delivered multiple times.
False.
A single SQS request can have from 1 to __________ messages, up to a maximum total payload of __________.
- 256KB.
Define “visibility timeout.”
A period of time during which SQS prevents other consumers from receiving and processing a message.
True or False: In SQS, a message will remain visible for 24 hours by default.
False. Visibility times out after 12 hours by default.
True or False: SQS guarantees FIFO delivery of messages.
False.
A single SQS API call with a 256KB payload will be billed as __________ requests.
Four.
What is the purpose of long polling in SQS?
It helps reduce costs by reducing the number of empty responses and eliminating false empty responses.
What is the maximum retention period for an SQS message?
14 days.
How much do FIFO SQS queue requests cost (per million requests)?
$0.50
What is the maximum long poll timeout?
20 seconds.
Long polling doesn’t return a response until __________, or the long poll times out.
A message arrives in the queue.
A period of time during which SQS prevents other consumers from receiving and processing a message is called the __________.
Visibility timeout.
True or False: SQS can be configured for auto-scaling.
True.
What size chunks are SQS messages billed at?
64KB.
What is the minimum size of an SQS message?
1 byte.
True or False: Your first 1 million SQS requests per month are free.
True.
What is the maximum size of an SQS message?
256KB.
Long polling doesn’t return a response until a message arrives in the queue, or __________.
The long poll times out.
With respect to message delivery, what should you do if your system requires that order be preserved?
Include sequencing info in the message so you can reorder the messages after the queue returns them.
Your EC2 instances download jobs from an SQS queue. However, they’re taking too long to process the messages. What API call can you use to extend the length of time to process the jobs?
ChangeMessageVisibility.
True or False: SQS messages can be delivered in any order.
True.
In SQS, to give yourself more time to process a message, what action could you take?
Use the ChangeMessageVisibility action to extend the message’s visibility timeout.
In SQS, what is the maximum amount of time that a message will remain visible?
12 hours.
SQS provides __________ message delivery.
At least once.
What is the maximum visibility of an SQS message in a queue?
12 hours.
The default visibility timeout for an SQS message is __________.
30 seconds.
In SQS, what is the default amount of time that a message will remain visible?
12 hours.
True or False: SQS supports exactly-once message delivery.
False. SQS only guarantees at-least-once message delivery.
SQS supports delivery of each message _______.
At least once.
What SQS mechanism helps reduce costs by reducing the number of empty responses?
Long polling.
What does the ChangeMessageVisibility SQS action do?
It restarts the timout period using the a new value.
How much do Standard SQS queue requests cost (per million requests)?
$0.40
Which Amazon service can you use in conjunction with SQS to “fan out” SQS messages to multiple queues?
SNS.
True or False: Every SQS action counts as a request.
True.
True or False: SQS does not guarantee first in, first out message delivery.
True.
