Sentinel architecture in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a Redis Sentinel instance monitoring a master named 'mymaster'.

Redis

sentinel monitor [1] 127.0.0.1 6379 2

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

Aredis1

Bslave1

Cmymaster

Dmaster1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a slave or random name instead of the master name.

Confusing the IP address with the master name.

The sentinel monitor command requires the master name to monitor. 'mymaster' is the default example name.

2fill in blank

medium

Complete the code to configure the quorum for Sentinel to agree on a failover.

Redis

sentinel monitor mymaster 127.0.0.1 6379 [1]

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

A3

B2

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Setting quorum to 0 disables failover detection.

Setting quorum too high causes failover never to trigger.

The quorum number defines how many Sentinels need to agree a master is down before failover starts. Usually, 2 or more is recommended.

3fill in blank

hard

Fix the error in the Sentinel failover command to trigger failover for 'mymaster'.

Redis

sentinel failover [1]

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

Amymaster

Bredis-master

Cslave1

Dmaster-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a slave or incorrect master name causes command failure.

Typo in the master name leads to no failover.

The failover command requires the exact master name monitored by Sentinel. 'mymaster' is the correct master name here.

4fill in blank

hard

Fill both blanks to configure Sentinel to notify a script and set the down-after-milliseconds timeout.

Redis

sentinel [1] mymaster /path/to/notify.sh
sentinel [2] mymaster 5000

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

Anotification-script

Bdown-after-milliseconds

Cclient-reconfig-script

Dfailover-timeout

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up script and timeout commands.

Using wrong command names causes Sentinel to ignore settings.

notification-script sets a script to run on events.
down-after-milliseconds sets how long Sentinel waits before marking master as down.

5fill in blank

hard

Fill all three blanks to create a Sentinel configuration snippet that sets the failover timeout, parallel syncs, and client reconfiguration script.

Redis

sentinel [1] mymaster 60000
sentinel [2] mymaster 1
sentinel [3] mymaster /path/to/reconfig.sh

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

Afailover-timeout

Bparallel-syncs

Cclient-reconfig-script

Ddown-after-milliseconds

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing down-after-milliseconds with failover-timeout.

Using notification-script instead of client-reconfig-script.

failover-timeout sets max time for failover.
parallel-syncs sets how many slaves can sync at once.
client-reconfig-script sets script to reconfigure clients after failover.