Hasitha's Tech Blessings

With Caron 4.2.0 release WSO2 moved to Hazelcast from Apache Tribes. We have also introduced a new JSR-107 (JCache) caching implementation.

Features of WSO2 Caching

Internal caching implementation of WSO2 has three main features

1. Local and distributed mode - If clustering is enabled cache work as a distributed cache. If not it works as a local cache. No code changes required. 
2. L1 and L2 caching model for distributed mode - The L1 cache is implemented using HashMaps, and the L2 cache is implemented using Hazelcast distributed maps. As a result, first the L1 cache is checked, and if there is a cache miss, then the L2 cache is checked. If the value is located in the L2 cache, then the value is also stored it in the L1 cache.
3. Multi-tenancy  - different tenants will have different caches working completely independently. This makes cache behavior  configurable tenant wise and improve data separation between tenants.

Distributed Caching

Using Distributed Caching for Web Applications 

import javax.cache.Cache;
import javax.cache.CacheConfiguration;
import javax.cache.CacheManager;
import javax.cache.Caching;
import java.util.concurrent.TimeUnit;

public class HazelcastCache {

    private static final String cacheName = "HAZELCAST_MEMORY_CACHE";
    private static final String cacheManagerName = "WSO2_CACHE_MANAGER";
    private static Cache cache = null;

    public static void init() {

        CacheManager cacheManager = Caching.getCacheManagerFactory().getCacheManager(
                cacheManagerName);
        cache = cacheManager.getCache(cacheName);
        if (null == cache) {
            cache = cacheManager
                    .createCacheBuilder(cacheName)
                    .setExpiry(
                            CacheConfiguration.ExpiryType.MODIFIED,
                            new CacheConfiguration.Duration(TimeUnit.MINUTES,
                                    10)).setStoreByValue(false).build();
        }
    }

    public static void write(String key, String value) {
        cache.put(key, value);
    }

    public static String read(String key) {
        String value = cache.get(key);
        return value;
    }
}

Following are the dependencies needed

<dependency>
    <groupId>javax.cache</groupId>
    <artifactId>cache-api</artifactId>
    <version>0.5</version>
    <scope>provided</scope>
</dependency>

A Sample Web Application