How do you integrate Redis as a distributed cache in Spring Boot? स्प्रिंग बूट में डिस्ट्रिब्यूटेड कैश के रूप में Redis को कैसे इंटीग्रेट करें?

Spring Boot's default cache manager (ConcurrentMapCacheManager) stores cached data in local JVM memory, which doesn't work across multiple instances of a horizontally scaled application — each instance would have its own inconsistent cache. Redis solves this by acting as a shared, external, in-memory cache that every instance reads from and writes to.

Adding spring-boot-starter-data-redis and setting spring.cache.type=redis is enough for Spring Boot to auto-configure a RedisCacheManager, so existing @Cacheable, @CachePut, and @CacheEvict annotations work unchanged while the underlying storage becomes centralized, persistent (optionally), and shared across all service instances.

spring:
  cache:
    type: redis
  data:
    redis:
      host: localhost
      port: 6379