Applications Flashcards
SQS Abbreviation?
Simple Queue Service
What is SQS?
Amazon SQS is a web service which gives you access to message queue service where we can store messages which needs to be processed.
SQS Used on which scenario?
SQS is used to decouple components in distributed application.
What are the different type of Queue available in SQS?
“Standard Queue
FIFO Queue”
What is Standard Queue?
Standard queue does not guarantee the message order & uniqueness of messages
What is FIFO Queue?
FIFO queue guarantee the message order & uniqueness of messages
How many transactions per second can Standard queue supports?
unlimited
How many transactions per second can FIFO queue supports?
300
SQS is based on which architecture?
Pull based
What is SQS message size?
256 KB
How long messages can be kept in Queue?
1 min to 14 days
What is visibility timeout?
Visibility timeout is the amount of time that the message is invisible in the queue after a reader pickup the message
What is maximum visibility timeout?
12 hrs.
What is SQS long polling?
long poll return only when the message is available.
What is SQS short polling?
short poll returns immediately even if the message is not available
What is important key word for SQS?
decouple
SQS retention period?
4 days
what is the first service in AWS?
SQS
SWF Abbreviation?
Simple workflow service
What is SWF?
SWF is a web service which coordinate task between distributed application.
How long SWF execution can last?
1 yr.
Do we get duplicated task in SWF?
no
SWF Actors?
“Workflow Starter
Deciders
Activity Worker”
SNS Abbreviation?
simple notification service
What is SNS?
SNS is a web service which allows us to send notification like SMS, email & push notification
SNS is push based?
yes
SNS stored in Multi AZ?
yes
What is Elastic transcoder?
It’s a media converter service in cloud; It convert videos to different format supported by mobile, tablet & laptop.
What is API gateway?
AWS API Gateway is a fully managed service where developers can publish,maintain,monitor & secure Web API at any scale.
API gateway scale automatically?
Yes
What are the end points we can have for API gateway?
“Lambda function
EC2 instance
Dynamo DB etc.”
What is API caching?
API caching allows you to cache your end point response till the TTL period
What is Cross Site Scripting?
Request website cant have different DNS name.
What is kinesis?
AWS Kinesis is a platform where we can process streaming data.
What are the different types of Kinesis?
“Kinesis Streams
Kinesis Firehouse
Kinesis Analytics”
What is Kinesis Streams?
Kinesis Streams can store streaming data in shards & later process it to other services.
What is Kinesis Firehouse?
Kinesis Firehouse can not store streaming data; we need to process the data immediately.
What is Kinesis Analytics?
Kinesis Analytics allows you to run analytic service on Kinesis streams & Kinesis Firehouse.
What is Shards?
Each data stream is stored in separate shards for processing.
How long we can store streaming data in Kinesis Streams?
24 hrs. to & days
What is Web Identity Federation?
Web Identity Federation services is used to authenticate users using social media accounts or google or amazon account.
What is AWS Cognito
“AWS Cognito service act as a broker between web identity federation & AWS.
It facilitate user access based on authentication token issued by Web identity federation.”
What is User pools in AWS Cognito?
User pool is user based. It handles user registeration,authentication & account recovery.
What is Identity Pool in AWS Cognito?
Identity pool authorize access to AWS resources.
What is Event Driven Architecture?
In Event driven architecture AWS Service respond to triggers generated by other aws services.
What is dead letter queue?
“SNS Service send message to DLQ if message is not delivered to end user.
SQS Service send message to DLQ if message is sent more that expected.
Lambda function send error to DLQ if error occur during execution of code.”
What is fanout pattern?
message is sent through SNS topic
What is S3 event notification?
“S3 Event notification feature enable you to receive notification certain event happed in S3 bucket.
These messages can be delivered to SQS,SNS or lambda function.”
What is publish/subscribe pattern?
Publisher -> Publish notification -> SNS Topic -> Subscribe notification -> Subscriber
Amazon’s SQS service guarantees a message will be delivered at least once?
Yes, Standard queues provide at-least-once delivery, which means that each message is delivered at least once
When you build an application layer on top of Amazon SWF, it restricts you to the use of specific programming languages.
“No, While there are a limited range of SDKs available for SWF, AWS provides an HTTP based API which allows you to interact using any language as long as you phrase the interactions in HTTP requests.
“
What application service allows you to decouple your infrastructure using message based queues?
“SQS, In IT the term ‘message’ can be used in the common sense, or to describe a piece of data of Task in an asynchronous queueing system such as MQSeries, RabbitMQ or SQS.
“
Amazon SWF is designed to help users ____.
Coordinate synchronous & asynchronous task
What happens when you create a topic on Amazon SNS?
An ARN is created; When a topic is created, Amazon SNS will assign a unique ARN (Amazon Resource Name) to the topic, which will include the service name (SNS), region, AWS ID of the user and the topic name. The ARN will be returned as part of the API call to create the topic. Whenever a publisher or subscriber needs to perform any action on the topic, they should reference the unique topic ARN.
What is Amazon Kinesis Data Streams?
A service on AWS that ingest & stores data streams for processing.
How can you prevent Amazon API Gateway from being overwhelmed by too many requests and improve overall performance across the APIs in your account?
Enable caching & set throttling limits
Amazon SWF ensures that a task is assigned only once and is never duplicated.
Yes
Does the Standard SQS message queue preserve message order and guarantee messages are only delivered once?
NO
What is the difference between SNS and SQS?
SNS is push based & SQS is pull based.
Amazon Kinesis Data Firehose is used for
“Amazon Kinesis Data Firehose is the easiest way to load streaming data into data stores and analytics tools. It can capture, transform, and load streaming data into Amazon S3, Amazon Redshift, Amazon Elasticsearch Service, and Splunk, enabling near real-time analytics with existing business intelligence tools and dashboards you’re already using today.
“
What are the key components of Kinesis Data Firehose?
Key components of Kinesis Data Firehose are: delivery streams, records of data and destinations. Producers, shards and consumers are components of Kinesis Data Streams.
True or False? At a high level an Amazon API Gateway is a “front door” for applications to access data, business logic, or functionality from your backend services.
Yes
In SWF, what does a “domain” refer to?
Domains provide a way of scoping Amazon SWF resources within your AWS account. All the components of a workflow, such as the workflow type and activity types, must be specified to be in a domain. It is possible to have more than one workflow in a domain; however, workflows in different domains can’t interact with each other.
Amazon SQS offers standard as the default queue type. Standard queues ensure that messages are delivered in the same order as they’re sent.
FALSE
You have discovered duplicate messages being processed in your SQS queue. How do you resolve this?
“Duplicate messages occur when a consumer does not complete its message processing and the visibility timeout of the message expires, making it visible for another consumer to obtain. Increasing the visibility timeout to enable the consumer processing to complete, will prevent duplicate messages.
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