คลังข้อมูล Cloudflare KV

Welcome to Cloudflare KV! It's a highly distributed key-value store that runs on Cloudflare's global network, right at the edge.

This means your data is stored incredibly close to your users, leading to extremely fast access and low latency. It's perfect for dynamic content, configuration, and caching.

A key-value store is like a simple dictionary or map. You store data as unique key-value pairs. The key is a unique identifier (a string), and the value is the data associated with that key.

• Keys: Think of them as unique names, like "user_id_123" or "website_config".
• Values: These are the actual data, which can be strings, numbers, JSON objects (as strings), or even binary data.

Why use KV at the edge?

• Speed: Data is served from the nearest Cloudflare data center, reducing latency.
• Simplicity: It's schemaless, making it easy to store and retrieve data without complex database schemas.
• Scalability: Automatically scales to handle massive traffic and global distribution.
• Cost-Effective: Often more economical for specific use cases compared to traditional databases.

Cloudflare KV is versatile for many edge-specific tasks:

• Caching: Storing frequently accessed API responses, HTML snippets, or static assets.
• Configuration: Managing dynamic feature flags, A/B test settings, or redirect rules.
• Personalization: Storing simple user preferences like theme choices or language settings.
• Rate Limiting: Keeping track of request counts per user or IP address.

Before using KV, you need to create a Namespace. A namespace is a logical container for your key-value pairs, keeping your data organized.

You can create a new KV Namespace through the Cloudflare dashboard or using the Wrangler CLI (Cloudflare's command-line tool).

To use a KV Namespace in your Worker, you must bind it in your wrangler.toml configuration file. This makes the KV namespace accessible as a global variable in your Worker script.

Here's how you define a binding:

The put() method is used to store data in your KV Namespace. It takes a key and a value as arguments. Values can be strings, ArrayBuffers, or ReadableStreams.

Try running this example Worker:

To retrieve a value, you use the get() method, providing the key. If the key doesn't exist, get() will return null.

This example tries to retrieve the setting we just stored:

If you need to remove a key-value pair from your namespace, use the delete() method with the key you wish to remove.

Here's how to delete the stored setting:

Cloudflare KV also provides a list() method to retrieve a list of keys within a namespace. This can be useful for administrative tasks or for understanding the contents of your KV store.

It often returns an object containing an array of keys and a list_complete boolean.

Which of the following statements about Cloudflare KV are true?

In this lesson, you've learned about Cloudflare KV, a powerful key-value store optimized for the edge. We covered:

• What KV is and its advantages for low-latency data access.
• Common use cases like caching and configuration.
• How to create a KV Namespace and bind it to a Cloudflare Worker.
• The core operations: put() to store, get() to retrieve, and delete() to remove data.

KV is a fundamental tool for building fast, scalable, and efficient edge applications!