Persistence and performance trade-off in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable Redis snapshotting with a save interval of 60 seconds and 1000 changes.

Redis

save [1] 1000

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

A30

B120

C60

D300

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a very short interval which may impact performance.

Confusing the time interval with the number of changes.

The save directive sets Redis to snapshot the dataset every specified seconds if at least the given number of changes occurred. Here, 60 seconds is the correct interval.

2fill in blank

medium

Complete the code to disable AOF persistence in Redis configuration.

Redis

appendonly [1]

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

Ano

Boff

Cauto

Dyes

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'off' instead of 'no' which is not valid in Redis config.

Confusing appendonly with save directives.

Setting appendonly no disables the Append Only File persistence in Redis, improving performance but risking data loss on crashes.

3fill in blank

hard

Fix the error in the Redis configuration line to set the AOF fsync policy to every second.

Redis

appendfsync [1]

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

Ano

Beverysec

Calways

Dsometimes

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'always' which syncs after every write and hurts performance.

Using 'no' which disables fsync and risks data loss.

The correct value for fsync every second is everysec. Other options either cause too frequent syncing or disable it.

4fill in blank

hard

Fill both blanks to configure Redis to save snapshots every 900 seconds if at least 1 change occurred and disable AOF.

Redis

save [1] 1
appendonly [2]

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

A900

Byes

Cno

D60

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the save interval with the number of changes.

Using 'yes' instead of 'no' to disable appendonly.

Setting save 900 1 means Redis saves a snapshot every 900 seconds if at least one change happened. Setting appendonly no disables AOF persistence.

5fill in blank

hard

Fill all three blanks to configure Redis to save snapshots every 300 seconds if 10 changes occurred, enable AOF, and set fsync policy to always.

Redis

save [1] 10
appendonly [2]
appendfsync [3]

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

A60

Byes

Calways

D300

Attempts:

3 left

💡 Hint

Common Mistakes

Using 60 instead of 300 for save interval.

Setting appendonly to 'no' which disables persistence.

Choosing 'everysec' instead of 'always' for fsync.

This configuration saves snapshots every 300 seconds if 10 changes happened, enables AOF persistence, and sets fsync to always for maximum durability but lower performance.