Lambda

Question 1

How much RAM can lambda allocate

Answer 1

128mb to 10,240mb (10GB)

Question 2

How many CPU to RAM

Answer 2

2 vCPUs - 1,769mb of RAM
6 vCPU - 10,240mb of RAM

Question 3

What is the timeout for Lambda

Answer 3

15 mins

Question 4

What is the concurrent execution limit for lambda

Answer 4

1000… can be increased if asked

Question 5

What is the Container Image Size

Answer 5

10GB

Question 6

What will happen if you go over the concurrency limit in Lambda

Answer 6

The remaining invocations will throttle

Question 7

How can you ensure that you dont go over the concurrency limit

Answer 7

Set a reserved concurrency at the function level

Question 8

Using CodeDeploy, what are the two options for shifting traffic

Answer 8

Linear: Grow traffic every N minutes until 100%
Linear10percentEvery3Minutes
Linear10percentEvery10Minutes

Canary: Try X percent then 100%
Canary10percent5Minutes
Canary10percent30Minutes

Question 9

What is X-Ray used for with Lambda

Answer 9

It is used to trace Lambda. Enable it in the Lambda configuration and it will run the X-Ray daemon for you

Question 10

If you deploy lambda in a VPC but want to talk to an application on the internet, how would you connect this

Answer 10

Create a NAT Gateway in a public subnet
Attach the NAT Gateway to an Internet Gateway and it will use that to connect to the application
Note: you can assign a fixed elastic IP to the NATGW so that you can only allow traffic from it

If it is an AWS application, then you can create an endpoint in the VPC to talk to the application without the internet

Question 11

What is the difference between Synchronous vs Asynchronous invocations in Lambda

Answer 11

Synchronous: Invoke Lambda directly & Get Response

Asynchronous: An event from S3 invokes lambda