applications1 Flashcards
SQS
web service that gives access to MQ. It is a distributed queing system that enables web applications to quickly and reliably queue messages.
Why use SQS
decouple so that they run independently easing message managemnet between components
Message size in SQS
256KB. But you can go upto 2GB in which case s3 storage will be used.
SQS queues types
Standard queues(default), FIFO queues
TPS of standard queues
unlimited tps. ensures message is delivered at least once. But occassionally more than one copy of the message may be delivered.
FIFO
order is stictly preserved. Exactly one time processing.
FIFO TPS
300tps. But have all other capabilities of standard queurs
SQS
First service on aws
Message retention
1min to 14 days. The default retention period is 4 days.
Visibility timeout max
12 Hours
Duplicates
After visibility timeout if the message is still not procesed the msg will become visible again and may result in duplicates
SQS long poll
doesn’t return a response until a message arrives in message queue or the long poll times out.
SWF
web service that makes it easy to coordinate work across distributed application components
SWF task
represents invocation of various processing steps in an application which can be performed by executable code, web service calls, human actions and scripts
SWF retention
upto 1 year
SWF api
presents a task oriented API vs a message oriented api by SQS
SWF
ensures task is assigned only once and is never duplicated.
SWF actors
workflow starters, deciders(controls the flows), active workers
SNS availability
To prevent messages from being lost it is stored redundantly across multiple AZs
SNS vs SQS
push vs pull
API gateway
Managed service that makes it easier to publish maintain monitor and secure API’s at any scale
What can API gateway do
- Expose https endpoint to restful api
- Connect serverlessly to Lambda and dynamoDB
- Send each API endpoint to different target
- scale effortlessly
- Track and control usage by apikey
- Throttle requests to prevent attacks
- connect to cloudwatch to log all requests for monitoring
- Maintain multiple versions of your API
API caching
Caches the response to reduce load and improve latency.
API caching
Caches the response to reduce load and improve latency.
CORS
Cross origin resource policy
Amazon Kinesis
is a platform to send your streaming data. Kinesis makes it easy to load and analyze your streaming data and build custom applications for your business needs
3 types of Kinesis
Kinesis streams, Kinesis firehose, Kinesis Analytics
Kinesis retention
Default 24Hours. Can store upto 7 days
Kinesis firehose
There is no data persistence.. lambda is used to process the data
Cognito user pools
is user based . It handles things like user registration, authentication, and account recovery
Cognito identity pools
authorise access to AWS resources
What happens when you create a topic on Amazon SNS
An Amazon Resource Name is created.
In SWF, what does a “domain” refer to?
A collection of related workflows
