Amazon DVA-C01 Practice Test - Questions Answers, Page 7

https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverlessgetting-started-hello-world.html

https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-clicommand-reference-sam-deploy.html https://docs.aws.amazon.com/serverless-applicationmodel/latest/developerguide/sam-cli-command-reference- sam-package.html

https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-visibilitytimeout.htmlIn SQS, messages remain there. It is the consumer’s responsibility to delete it, once consumed andprocessed.

Refer AWS documentation - Lambda Best Practices

Take advantage of Execution Context reuse to improve the performance of your function. Make sure any externalized configuration or dependencies that your code retrieves are stored and referenced locally after initial execution. Limit the re-initialization of variables/objects on every invocation.

Instead use static initialization/constructor, global/static variables and singletons. Keep alive and reuse connections (HTTP, database, etc.) that were established during a previous invocation.

https://aws.amazon.com/step-functions/

https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/SelectEngine.html

CloudWatch definitely. Random key prefixes is still a valid method of improving performance by using parallel reads. It doesn't mention prefix hashing. For instance prefixes 1/,2/,3/,4,5/ could provide 5 x parallel streams for S3 as opposed to all objects being in a single folder/prefix e.g. dev/

https://docs.aws.amazon.com/AmazonS3/latest/dev/optimizing-performance.html"There are no limits to the number of prefixes in a bucket. You can increase your read or writeperformance by parallelizing reads. For example, if you create 10 prefixes in an Amazon S3 bucket toparallelize reads, you could scale your read performance to 55,000 read requests per second." Theassumption that prefixes don't matter is incorrect, as described by "Amazon S3 performance guidelines recommended randomizing prefix naming with **hashed characters** to optimize performance for frequent data retrievals. You no longer have to randomize prefix naming for performance, and can use sequential date-based naming for your prefixes"

Refer AWS documentation - DynamoDB Accelerator

Amazon DynamoDB Accelerator (DAX) is a fully managed, highly available, inmemory cache for DynamoDB that delivers up to a 10x performance improvement – from milliseconds to microseconds – even at millions of requests per second. DAX does all the heavy lifting required to add in-memory acceleration to your DynamoDB tables, without requiring developers to manage cache invalidation, data population, or cluster management. Now you can focus on building great applications for your customers without worrying about performance at scale.

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.Errors.html