Heartbeat mechanism in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the main purpose of a heartbeat mechanism.

HLD

The heartbeat mechanism is used to [1] the health status of system components.

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Adelete

Bignore

Cmonitor

Dencrypt

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'ignore' because it sounds unrelated.

Confusing heartbeat with encryption or deletion.

The heartbeat mechanism is designed to monitor the health status of system components by sending regular signals.

2fill in blank

medium

Complete the code to specify the typical interval for sending heartbeat signals.

HLD

Heartbeat signals are usually sent every [1] seconds to ensure timely detection of failures.

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A5

B60

C300

D0.1

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 60 seconds which is too slow for quick failure detection.

Choosing 0.1 seconds which is too frequent and costly.

Heartbeat signals are commonly sent every 5 seconds to balance between timely failure detection and network overhead.

3fill in blank

hard

Fix the error in the failure detection condition.

HLD

If no heartbeat received for [1] times the interval, mark the component as failed.

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A1

B3

C10

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 1 which is too sensitive and causes false alarms.

Choosing 10 which delays failure detection too much.

Waiting for 3 missed heartbeats is a common practice to avoid false positives due to network delays.

4fill in blank

hard

Fill both blanks to complete the heartbeat message format and its transport protocol.

HLD

Heartbeat message format: [1]; Transport protocol: [2]

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AJSON

BXML

CTCP

DUDP

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing TCP which adds overhead and latency.

Choosing XML which is heavier than JSON.

Heartbeat messages are often formatted in JSON for simplicity and sent over UDP for low latency.

5fill in blank

hard

Fill all three blanks to complete the failure detection logic in pseudocode.

HLD

if missed_heartbeats > [1] and last_heartbeat_time < current_time - [2] * [3]:
    mark_component_failed()

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A3

Binterval

Ctimeout

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'timeout' as a variable instead of 'interval'.

Setting missed_heartbeats threshold too low or too high.

The system marks a component as failed if missed heartbeats exceed 3 and the last heartbeat was received more than interval * 5 seconds ago.