Monitoring with INFO command in Redis - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the Redis INFO command do?

The INFO command shows detailed information and statistics about the Redis server, like memory usage, clients connected, and server uptime.

beginner

How can you get information about memory usage using the INFO command?

Use INFO memory to get details about Redis memory consumption, including used memory and peak memory.

beginner

What section of the INFO command output shows connected clients?

The Clients section shows how many clients are connected and their details.

beginner

How do you use the INFO command to get all server statistics?

Simply run INFO without arguments to get all sections of server stats in one output.

beginner

Why is the INFO command useful for monitoring Redis?

It helps you understand Redis health and performance by showing real-time stats like memory, clients, CPU, and persistence info.

Which command shows detailed Redis server statistics?

A CONFIG GET

B MONITOR

C INFO

D PING

The INFO command provides detailed server statistics, unlike MONITOR which shows live commands.

How do you get only memory-related info from Redis?

A INFO persistence

B INFO memory

C INFO cpu

D INFO clients

INFO memory returns memory usage details specifically.

What does the INFO command output NOT include?

A Live command stream

B Connected clients

C Memory usage

D CPU usage

Live command stream is shown by MONITOR, not INFO.

Which section in INFO output shows persistence info?

A Stats

B Clients

C Memory

D Persistence

The Persistence section shows info about saving data to disk.

Running INFO without arguments returns:

A All server statistics

B Only CPU info

C Only client info

D Only memory info

INFO without arguments returns all available server stats.

Explain how the Redis INFO command helps in monitoring server health.

Think about what stats you need to check Redis health.

Describe how to use the INFO command to check memory usage and what information you get.

Focus on the memory section details.

Practice

1. What does the Redis INFO command primarily provide?

easy

A. A snapshot of the Redis server status and statistics

B. A list of all keys stored in Redis

C. The configuration file contents

D. A backup of the Redis database

Solution

1. Step 1: Understand the purpose of INFO command

   The INFO command is designed to give a snapshot of the Redis server's current status and statistics.

2. Step 2: Compare with other options

   Listing keys, showing config files, or backups are done by other commands, not INFO.

3. Final Answer:

   A snapshot of the Redis server status and statistics -> Option A

4. Quick Check:

   INFO = Server status snapshot [OK]

Hint: INFO shows server stats, not keys or configs [OK]

Common Mistakes:

• Confusing INFO with commands like KEYS or CONFIG
• Thinking INFO returns data backups
• Assuming INFO lists all stored keys

2. Which of the following is the correct syntax to get only the memory section info from Redis?

easy

A. INFO --section=memory

B. INFO -memory

C. GET INFO memory

D. INFO memory

Solution

1. Step 1: Recall Redis INFO command syntax

   The correct syntax to get a specific section is INFO section_name, for example, INFO memory.

2. Step 2: Eliminate incorrect options

   Options with dashes or GET keyword are invalid Redis command syntax.

3. Final Answer:

   INFO memory -> Option D

4. Quick Check:

   INFO section_name = INFO memory [OK]

Hint: Use INFO followed by section name without dashes [OK]

Common Mistakes:

• Adding dashes before section name
• Using GET keyword with INFO
• Using double dashes or equal signs

3. Given the Redis INFO output snippet:

used_memory:1024000
connected_clients:5
uptime_in_seconds:3600

What does connected_clients indicate?

medium

A. Number of clients currently connected to Redis

B. Number of keys stored in Redis

C. Total memory used by Redis in bytes

D. Redis server uptime in seconds

Solution

1. Step 1: Identify the meaning of connected_clients

   The connected_clients field shows how many clients are currently connected to the Redis server.

2. Step 2: Differentiate from other fields

   used_memory is memory usage, uptime_in_seconds is server uptime, and keys count is not shown here.

3. Final Answer:

   Number of clients currently connected to Redis -> Option A

4. Quick Check:

   connected_clients = active connections [OK]

Hint: connected_clients means active users connected now [OK]

Common Mistakes:

• Confusing connected_clients with key count
• Mixing memory usage with client count
• Assuming uptime is client count

4. You run INFO client but get an error. What is the most likely cause?

medium

A. Redis server is down

B. You need to run INFO without any arguments

C. The section name 'client' is misspelled or unsupported

D. You must use GET instead of INFO

Solution

1. Step 1: Check valid section names for INFO

   Redis INFO supports specific section names like 'clients' (plural), not 'client' (singular).

2. Step 2: Understand error cause

   Using an invalid or misspelled section name causes an error, not server down or wrong command usage.

3. Final Answer:

   The section name 'client' is misspelled or unsupported -> Option C

4. Quick Check:

   INFO section names must be exact [OK]

Hint: Use exact section names; 'clients' not 'client' [OK]

Common Mistakes:

• Using singular instead of plural section names
• Assuming server is down without checking
• Trying GET command instead of INFO

5. You want to monitor Redis memory usage and client connections continuously. Which approach using the INFO command is best?

hard

A. Run INFO once and save output to a file

B. Run INFO memory and INFO clients repeatedly in a script with a delay

C. Use INFO all once and check manually later

D. Run CONFIG GET memory and CONFIG GET clients repeatedly

Solution

1. Step 1: Identify continuous monitoring needs

   To monitor memory and clients continuously, you need repeated INFO queries with a delay to track changes over time.

2. Step 2: Evaluate options

   Running INFO memory and INFO clients repeatedly in a script fits this need. Running once or using CONFIG GET won't provide continuous updates.

3. Final Answer:

   Run INFO memory and INFO clients repeatedly in a script with a delay -> Option B

4. Quick Check:

   Repeated INFO calls = continuous monitoring [OK]

Hint: Use repeated INFO calls in script for live monitoring [OK]

Common Mistakes:

• Running INFO only once for monitoring
• Using CONFIG GET which is for config, not stats
• Running INFO all once expecting continuous data