Application Services Flashcards
What is SQS?
A message queue to de-couple applications
Is SQS pull or push based?
pull
What is the size of SQS messages?
- Can be up to 2gb, but need to use S3.
What is the SQS visibility timeout max?
12 hours
How long can SQS messages stay in queue?
1 min to 14 days. Default is 4 days
What is the SQS visibility timeout?
Amount of time that a message is invidible in queue after a reader picks up that message
What happens if an SQS job processes a message before the invisibility time out expires?
The message should be deleted from the queue by the job worker.
What happens if an SQS job does not complete before the visibility time out expires?
The message becomes visible again for another reader to process
What is the difference between SQS short and long polling?
Short polling will return a response immediately even if the queue is empty.
Long polling doesn’t return a response until a message arrives in the queue.
What are the SQS queue types?
FIFO or standard
What is the max retention for SWF?
1 year
Which message service presents a task orientated API?
SWF
Which message service offers a message orientated API?
SQS
Which message service ensure that a task is assigned only once and is never duplicated?
SWF
Which message service keeps track of events?
SWF
Which service requires application level tracking?
SQS
What are the three SWF actors?
Workflow starter
Deciders
Activity worker
What are SNS subscribers?
Subscribers are clients interested in receiving notifications from topics of interest; they can subscribe to a topic or be subscribed by the topic owner. Subscribers specify the protocol and end-point (URL, email address, etc.) for notifications to be delivered.
Which is a push based message service?
SNS
What is elastic transcoder?
media transcoder in the cloud
What are the three kinesis types?
stream
firehose
analytics
What is kinesis streams?
Kinesis streams accepts streaming data and breaks up it into shards for each type of data. EC2 data consumers analyze the data inside the shards and outputs it to DynamoDB/S3/EMR/Redshift/etc…
What is kinesis firehose?
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. It is a fully managed service that automatically scales to match the throughput of your data and requires no ongoing administration. It can also batch, compress, and encrypt the data before loading it, minimizing the amount of storage used at the destination and increasing security.
What service decouples application components to run independently?
SQS
Which SQS queue type would you use if you need unlimited messages and best effort ordering?
standard
Which SQS queue type would you use if you need unlimited messages and correct ordering?
FIFO
Is SQS pull or push based?
Pull
What AWS application service would you use to coordinate work across applications?
SWF
What SWF component interacts with SWF to get tasks?
Workers
What SWF component controls coordination of tasks
Deciders
What SWF component would you use to isolate SWF worflows
Domains
What AWS application service would you use to send notifications from the cloud to SMS or email?
SNS
What AWS application service would you use to transcode media?
Elastic transcoder
What AWS application service would you use to manage APIs?
API gw
Can API gateway provide caching to improve performance?
Yes
What AWS application service would you send streaming data to for analysis?
kinesis
Which kinesis service would you use to accept data from multiple sources to store for 24 hours to 7 days that are then forwarded to consumers?
Streams
Which kinesis service would you use to accept data from multiple sources to analyze in real time to then store in S3?
Firehose
Which kinesis service would you use to perform SQL queries on kinesis streams or firehose?
analytics
What is cognito
Provides login federation using FB, google , amazon
How does cognito work?
Authenticates with web ID provider, recieve temporary token, exchange with AWS credentials to provide access by allowing them to assume role
What is a cognito user pool?
User Pools are user based.
It handles things like user registration, authentication, and account recovery.
What service does cognito identity pools provide?
Identity Pools provide temporary AWS credentials to access AWS services like S3 or DynamoDB.
What is the difference between SNS and SQS?
SNS is a push notification service, whereas SQS is message system that requires worker nodes to poll a queue.
What happens when you create a topic on Amazon SNS?
An Amazon Resource Name is created.
What SNS Subscription endpoint Protocols are available?
HTTP/HTTPS (URL)
email (text)/email (json)
SQS Standard Queue
SMS Text messages
