Using multiple cache implementations with Spring Cache

Question

I'm working on a Spring Boot app where I need to use both distributed (e.g. Hazelcast) and local (e.g. Guava) caches. Is there a way to configure Spring Cache to use both when using @Cacheable and decide which implementation is needed based on the cache name?

I tried with creating a configuration for both HZ and Guava defining the cache names inside, but Spring complains that it couldn't find the cache name that is supposed to handled by HZ. When I use exclusively HZ or Guava they work.

Solution 1

Which implementation is needed based on the cache name?

Not based on the cache name, but yes - based on the CacheManager it is possible. Declare one of them as @Primary CacheManager, as follows:

@Configuration
@EnableCaching
@PropertySource(value = { "classpath:/cache.properties" })
public class CacheConfig {

    @Bean
    @Primary
    public CacheManager hazelcastCacheManager() {
        ClientConfig config = new ClientConfig();
        HazelcastInstance client = HazelcastClient.newHazelcastClient(config);
        return new HazelcastCacheManager(client);
    }

    @Bean
    public CacheManager guavaCacheManager() {
         GuavaCacheManager cacheManager = new GuavaCacheManager("mycache");
           CacheBuilder<Object, Object> cacheBuilder = CacheBuilder.newBuilder()
           .maximumSize(100)
           .expireAfterWrite(10, TimeUnit.MINUTES);
           cacheManager.setCacheBuilder(cacheBuilder);
           return cacheManager;
    }

}

and specify it at class level as:

@Service
@CacheConfig(cacheManager="hazelcastCacheManager")
public class EmployeeServiceImpl implements IEmployeeService {

}

or at method level as:

@Service
public class EmployeeServiceImpl implements IEmployeeService {

    @Override
    @Cacheable(value = "EMPLOYEE_", key = "#id", cacheManager= "guavaCacheManager")
    public Employee getEmployee(int id) {
        return new Employee(id, "A");
    }

}

If you have to stick with Cache name only, then you can multiple CacheManager.

Solution 2

You have 2 options.

One is as @Arpit mentioned: Define multiple CacheManagers and specify it in either method-level annotations (@Cacheable, @CachePut, etc) or class-level annotations (@CacheConfig)

You can also create custom annotations:

@CacheConfig(cacheManager = "guavaCacheManager")
@Target(value = ElementType.TYPE)
@Retention(value = RetentionPolicy.RUNTIME)
public @interface GuavaCacheable {
}

@GuavaCacheable
@Service
public class MyServiceImpl implements MyService {
}

And as the second option, you can create a custom cache resolver if your caching needs are complex.

You can look here for a custom CacheResolver that manages multiple CacheManagers and supports enabling/disabling. But for most cases, CacheResolver is overkill.

Comments

[Balazs]

I followed your solution but got this exception on startup: java.lang.IllegalStateException: No CacheResolver specified, and no unique bean of type CacheManager found. Mark one as primary (or give it the name 'cacheManager') or declare a specific CacheManager to use, that serves as the default one. I tried to use the name the error message mentions but it didn't help. Any idea on that?

[Balazs]

Thanks for the help, it works perfectly! It's a shame that Spring doesn't cover this part properly in their docs as it's fairly simple once you get some guidelines.

[Soumitri Pattnaik]

@Arpit , @Balazs can we use both these cache managers in one method @Cachable ?

[Arpit Aggarwal]

@SoumitriPattnaik no, only one at a time, as cacheManager is a String instance in @Cachable and not Array.

[vigamage]

hello, I used this way. But still, Spring cannot identify which cache manager to autowire into my service class. any help please?

[Myth]

As hazelcastCacheManager is annotated with @Primary so no need to specify cacheManager= "hazelcastCacheManager" specifically.