Lambda

Question 1

T or F

Lambda is a computer service where you can upload your code and create a Lambda function.

Answer 1

True

Question 2

T or F

Lambda takes care of provisioning and managing servers that you use to run the code.

Answer 2

true

Question 3

T or F

With Lambda, you don’t have to worry about operating systems, patching, scaling, etc. You cna use Lambda in the following ways.

Answer 3

True

Question 4

T or F

As an event driven compute service where AWS Lambda runs your code in response to events. These events could be changes to data in an AWS bucket or an AZ dynamoDB table.

Answer 4

True

Question 5

T or F

As a compute service to run your code in response to HTTP requests using API GW or API calls made using AWS SDKs.

Answer 5

True

Question 6

What languages does Lambda use?

1. nodejs
2. java
3. python
4. C#
5. Go

Answer 6

All of the above

Question 7

Pricing

T or F

of requests

first 1 million requests are free.

$.20 per 1 million requests thereafter

Duration is calculated from the time your code begins executing until it returns or otherwise temrinates, rounded up to the nearest 100ms. The price depends on the amount of money you allocate to your function. You are charged .00001667 for every GB-second used.

Answer 7

True

Question 8

Why Lambda?

1. no servers
2. continuous scaling
3. super cheap

Answer 8

all of the above

Question 9

T or F

Lambda scales up not out automatically.

Answer 9

False

Lambda scales out (not up) automatically

Question 10

T or F

Lambda functions are independent, 1 event = 1 function

Answer 10

True

Question 11

T or F

Lambda is serverless

Answer 11

True

Question 12

T or F

Lambda functions cannot trigger other lambda functions

Answer 12

false.

Lambda functions can trigger other lambda functions, 1 event can = x functions if functions trigger other functions.

Question 13

T or F

Lambda can do things globally. You can use it to back up S3 to other S3 buckets.

Answer 13

true

Question 14

WHen you use _____ in Lambda, you can publish one or more versions of your Lambda function. AS a result, you can work with different variations of your Lambda function in your development workflow, such as development, beta, and prod. Each Lambda function version has a unique ARN. After you publish, it is immutable (can’t be changed)

Answer 14

versioning

Question 15

AWS Lambda maintains your latest function code in the ______ version. When you update your function code, AWS Lambda replaces the code in teh ____ version of teh Lambda code.

Answer 15

$LATEST

$LATEST

Question 16

You can refer to this function using its ______. There are 2 _____ associated with this internal version.

Answer 16

ARN and ARNs

Question 17

This function ARN wiht the version suffix

arn:aws:lambda:aws-region:acct-id:function:helloworld:$LATEST

Answer 17

Qualified ARN

Question 18

The function ARN without the version suffix:

arn:aws:lambda:aws-region:acct-id:function:helloworld

Answer 18

Unqualified ARN

Question 19

After initially creating a Lambda function (the $LATEWT version), you can publish a version 1 of it. By creating an _____ named PROD that points to version 1, you can now use the PROD alias to invoke version 1 of the Lambda function.

Answer 19

ALIAS

Question 20

How do you update Lambda’s in production.

Answer 20

You can update the code (the $LATEST version) with all of your improvements and then publish another stable version (V2). You can promote V2 to prod by remapping the PROD alias so that it paints to V2. If you find something wrong, you can easily roll back the prod version to V1 by remapping the PROD alias so that it points to V1.

Question 21

T or F

You can have multiple versions of Lambda functions

Answer 21

True

Question 22

T or F

The latest version of your Lambda will use $LATEST

Answer 22

True

Question 23

T or F

Qualified version will not use $LATEST, but the unqualified will use it.

Answer 23

False

The qualified version will use $LATEST, unqualified will not use it.

Question 24

T or F

Versions are immutable (can’t be changed)

Answer 24

True

Question 25

T or F

You can split traffic using alias to diff version

Answer 25

True

Question 26

T or F

you can’t split traffic with $LATEST, instead crete an alias to $LATEST

Answer 26

true

Question 27

This allows you to visualize and test your serverless apps.

Answer 27

Steps Functions

Question 28

_____ provides a graphical console to arrange and visualize the components of your app as a series of steps. This makes it simple to build and run multistep apps.

Answer 28

Step Functions

Question 29

_____ auto triggers and tracks each step and retries when there are errors, so your app executes in order and as expected. They also log the state of each step, so when things do go wrong, you can diagnose and debug problems quickly.

Answer 29

Step functions.

Question 30

T or F

Step functions are a great way to visualize your serverless application

Answer 30

True

Question 31

T or F

Step functions automatically trigger and tracks each step

Answer 31

True

Question 32

T or F

Step functions log the state of each step, so if something goes wrong, you can track what went wrong and where.

Answer 32

True

Question 33

concurrent executions

• not necessary to memorize lots of limits for the exam
• be aware that tehre i a concurrent execution limit for lambda
• safety faeture to limit the number of concurrent executions across all functions in a given region pre account.

Answer 33

yes

Question 34

concurrent executions

default is _____ per region

TooManyRequestException

HTTP Status Code: ____

Request throughput limit exceeded

Answer 34

1000

429

Question 35

concurrent executions

• if you have many lambda functions running in teh same region and you suddenly start seeing new invocation requests being rejected, then you may have hit your limit.
• at ACG, our daily usage is around 6.5m Lambda invocations per day in us-east-1
• request an increase on this limit by submitting a request to the aws support center
• ____ ____ guarantees that a set number of executions which wil always be available for our critical function, however this also acts as a limit.

Answer 35

reserved concurrency

Question 36

Lambda versions

• when you create a lambdad functioin, there is only one version: $LATEST
• when yoou upload a new version of the code to lambda, this version will become $LATEST
• you can create multiple version of your function code and use aliases t referernce the version you want to ues as part of the ARN
• IN develoopment you might want to maintain a few versionns of the same function as you develop and test your code
• an alias is like a pointer to a specific veersion of the funciton code

Answer 36

yes

Question 37

if ou upload hte new code to lambda, the new code becomes the $LATEST version

Answer 37

T

Question 38

if your appuses an alias, remember to update the ARN that you are using if you want to use te new code

Answer 38

T

Question 39

enabling lambda to access VPC resources

• to enable this, you need to allow the function to connect to the private subnet
• lambda needs the following VPC configuration info so that it can connect to the VPC::

private subnet id

security group ID (with required access)

lambda uses this info to setup ENIs using an available IP address from your private subnet