Memorystore for Redis caching in GCP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Redis instance with the correct tier.

GCP

gcloud redis instances create my-redis-instance --size=1 --region=us-central1 --tier=[1] --authorized-network=default

Drag options to blanks, or click blank then click option'

ASTANDARD_HA

BBASIC

CPREMIUM

DENTERPRISE

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing STANDARD_HA when only basic caching is needed.

Using PREMIUM or ENTERPRISE tiers without need.

The BASIC tier is the simplest Redis instance type for Memorystore, suitable for development and testing.

2fill in blank

medium

Complete the code to specify the Redis version when creating an instance.

GCP

gcloud redis instances create cache-1 --size=2 --region=us-east1 --tier=BASIC --redis-version=[1] --authorized-network=default

Drag options to blanks, or click blank then click option'

AREDIS_6_X

Bredis_latest

CREDIS_4_0

DREDIS_5_0

Attempts:

3 left

💡 Hint

Common Mistakes

Using REDIS_5_0 which is older and less recommended.

Using redis_latest which is not a valid version string.

The REDIS_6_X version is a common supported version for Memorystore, offering newer features and better performance.

3fill in blank

hard

Fix the error in the command to allow authorized network access.

GCP

gcloud redis instances create cache-2 --size=3 --region=us-west1 --tier=STANDARD_HA --authorized-network=[1]

Drag options to blanks, or click blank then click option'

Adefault

Bdefault-network

Cdefault-vpc

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect network names like 'default-network' or 'default-vpc'.

Leaving the flag empty or misspelled.

The authorized-network flag requires the name of the VPC network, commonly default for the default VPC.

4fill in blank

hard

Fill both blanks to configure a Redis instance with a specific memory size and region.

GCP

gcloud redis instances create my-cache --size=[1] --region=[2] --tier=BASIC --authorized-network=default

Drag options to blanks, or click blank then click option'

A4

Bus-central1

Cus-east1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up region names or using unsupported sizes.

Using a size too large for the tier.

The size is set to 2 GB and the region to us-central1 for this Redis instance.

5fill in blank

hard

Fill all three blanks to create a Redis instance with high availability, a specific version, and authorized network.

GCP

gcloud redis instances create ha-cache --size=5 --region=[1] --tier=[2] --redis-version=[3] --authorized-network=default

Drag options to blanks, or click blank then click option'

Aus-east1

BSTANDARD_HA

CREDIS_6_X

DBASIC

Attempts:

3 left

💡 Hint

Common Mistakes

Using BASIC tier instead of STANDARD_HA for high availability.

Choosing unsupported Redis versions.

Incorrect region names.

The instance is created in us-east1 region, with STANDARD_HA tier for high availability, and Redis version REDIS_6_X.

Practice

1. What is the main purpose of Memorystore for Redis in Google Cloud?

easy

A. To run virtual machines

B. To permanently store large files

C. To temporarily store data to speed up applications

D. To manage user authentication

Solution

1. Step 1: Understand Memorystore for Redis role

   Memorystore for Redis is designed to cache data temporarily to improve app speed.

2. Step 2: Compare options with purpose

   Options A, B, and D describe unrelated services or functions.

3. Final Answer:

   To temporarily store data to speed up applications -> Option C

4. Quick Check:

   Memorystore caches data = C [OK]

Hint: Memorystore caches data temporarily to speed apps [OK]

Common Mistakes:

• Confusing caching with permanent storage
• Thinking it manages VMs or authentication
• Assuming it stores large files permanently

2. Which of the following is the correct command snippet to create a Memorystore Redis instance with 1 GB memory in region us-central1?

easy

A. gcloud redis create instance my-redis --memory=1GB --region=us-central1

B. gcloud redis instances create my-redis --size=1 --region=us-central1

C. gcloud redis instances create my-redis --memory=1GB --zone=us-central1-a

D. gcloud redis instances new my-redis --size=1GB --region=us-central1

Solution

1. Step 1: Recall correct gcloud command syntax

   The correct command uses 'gcloud redis instances create' with '--size' in GB and '--region'.

2. Step 2: Check each option for syntax errors

   gcloud redis instances create my-redis --size=1 --region=us-central1 matches correct syntax. Options A, C, and D use wrong flags or commands.

3. Final Answer:

   gcloud redis instances create my-redis --size=1 --region=us-central1 -> Option B

4. Quick Check:

   Correct gcloud create syntax = B [OK]

Hint: Use 'gcloud redis instances create' with --size and --region [OK]

Common Mistakes:

• Using --memory instead of --size
• Using 'create instance' instead of 'instances create'
• Specifying zone instead of region

3. Given this Python code snippet using Redis client connected to Memorystore, what will be printed?

import redis
client = redis.Redis(host='10.0.0.5', port=6379)
client.set('color', 'blue')
print(client.get('color'))

medium

A. None

B. 'blue'

C. blue

D. b'blue'

Solution

1. Step 1: Understand Redis get returns bytes

   Redis client returns values as bytes, so 'client.get' returns b'blue'.

2. Step 2: Check print output

   Printing bytes shows with b'' prefix, so output is b'blue'.

3. Final Answer:

   b'blue' -> Option D

4. Quick Check:

   Redis get returns bytes = b'blue' [OK]

Hint: Redis get returns bytes, not string [OK]

Common Mistakes:

• Expecting plain string instead of bytes
• Confusing Redis set/get syntax
• Assuming None if key exists

4. You created a Memorystore Redis instance but your app cannot connect. Which is the most likely cause?

medium

A. The Redis instance is in a different VPC network than the app

B. The Redis instance size is too small

C. The Redis instance region is the same as the app

D. The Redis instance is running the wrong Redis version

Solution

1. Step 1: Identify common connectivity issues

   Memorystore requires the app and Redis instance to be in the same VPC or connected networks.

2. Step 2: Evaluate options

   The Redis instance is in a different VPC network than the app correctly identifies network mismatch causing connection failure. Size, region, or version mismatches do not block connection.

3. Final Answer:

   The Redis instance is in a different VPC network than the app -> Option A

4. Quick Check:

   Network mismatch blocks connection = A [OK]

Hint: Check VPC network match for app and Redis [OK]

Common Mistakes:

• Blaming size or region for connection failure
• Ignoring network setup
• Assuming version mismatch blocks connection

5. You want to reduce database load by caching user session data using Memorystore for Redis. Which approach is best to ensure sessions expire automatically after 30 minutes?

hard

A. Set a TTL (time-to-live) of 1800 seconds on each session key when storing it

B. Manually delete session keys every 30 minutes using a cron job

C. Use a Redis instance with a 30-minute auto-shutdown setting

D. Store sessions without expiration and rely on database cleanup

Solution

1. Step 1: Understand session expiration in Redis

   Redis supports TTL on keys to expire them automatically after a set time.

2. Step 2: Evaluate options for automatic expiration

   Set a TTL (time-to-live) of 1800 seconds on each session key when storing it uses TTL correctly. Manually delete session keys every 30 minutes using a cron job is manual and error-prone. Use a Redis instance with a 30-minute auto-shutdown setting is invalid Redis feature. Store sessions without expiration and rely on database cleanup does not expire sessions.

3. Final Answer:

   Set a TTL (time-to-live) of 1800 seconds on each session key when storing it -> Option A

4. Quick Check:

   Use TTL for auto-expire sessions = D [OK]

Hint: Use TTL on keys for automatic expiration [OK]

Common Mistakes:

• Relying on manual deletion
• Expecting Redis instance to auto-shutdown
• Not setting expiration causing stale sessions