How do you implement cache expiration policies in Spring Boot?

Table of Contents

• Introduction
• Configuring Cache Expiration Policies
  • 1. Using In-Memory Caches (Ehcache or Caffeine)
    • Example: Ehcache Configuration
    • Example: Caffeine Configuration
  • 2. Using Distributed Caches (Redis)
    • Example: Redis Cache Configuration
    • Example: Expire Specific Keys
  • 3. Custom Expiration Policies
    • Example: Custom Expiration with Scheduler
• Practical Examples
  • Example 1: Applying TTL to Specific Cache Entries
  • Example 2: Expiring Redis Keys Manually
• Conclusion

Introduction

Cache expiration policies in Spring Boot are critical for maintaining the balance between performance and data freshness. By defining time-to-live (TTL) or idle time policies, you ensure that outdated or unused cache entries are removed, allowing your application to serve accurate data and manage memory efficiently. This guide provides insights into implementing cache expiration in Spring Boot.

Configuring Cache Expiration Policies

1. Using In-Memory Caches (Ehcache or Caffeine)

In-memory caches like Ehcache or Caffeine allow you to define expiration policies directly in their configurations.

Example: Ehcache Configuration

• This configuration sets a TTL of 600 seconds for the products cache, ensuring entries expire after 10 minutes.

Example: Caffeine Configuration

• Entries in the Caffeine cache expire 10 minutes after being written.

2. Using Distributed Caches (Redis)

For distributed caches like Redis, expiration policies can be set at the cache or individual key level.

Example: Redis Cache Configuration

• Sets a default TTL of 10 minutes for all entries in the Redis cache.

Example: Expire Specific Keys

• Applies a TTL of 10 minutes to the products cache manually.

3. Custom Expiration Policies

For more control, you can implement custom expiration logic using scheduled tasks.

Example: Custom Expiration with Scheduler

• Manually clears expired entries at regular intervals.

Practical Examples

Example 1: Applying TTL to Specific Cache Entries

• Use cache configurations to automatically expire entries after a specified time.

Example 2: Expiring Redis Keys Manually

• Stores a product in the Redis cache with a TTL of 10 minutes.

Conclusion

Implementing cache expiration policies in Spring Boot is essential for maintaining performance and ensuring data freshness. Whether using in-memory caches like Ehcache or Caffeine or distributed caches like Redis, you can configure TTL and idle time policies effectively. By leveraging these strategies, you ensure that your application efficiently handles caching while serving accurate and updated data.