5.2.0-beta5

Enhanced Client-side caching

We've substantially improved server-assisted, client-side caching in response to user feedback. It is currently a beta grade.

Client-side caching is supported exclusively with the RESP3 protocol and is available in UnifiedJedis, JedisPooled, and JedisCluster and other classes.

How to try Client-Side Caching

1. Install Jedis 5.2.0-beta5
2. Use the following code example to get started:

public class CSCExampleTest {
  public static void main() {

    HostAndPort node = HostAndPort.from("localhost:6379");
    JedisClientConfig clientConfig = DefaultJedisClientConfig.builder()
        .resp3()                // RESP3 protocol is required for client-side caching
        //.user("myuser")       // Redis server username (optional)
        //.password("mypass")   // Redis user's password (optional)
        .build();

    CacheConfig cacheConfig = getCacheConfig();
    Cache cache = CacheFactory.getCache(cacheConfig);

    try (UnifiedJedis client = new UnifiedJedis(node, clientConfig, cache)) {
      client.set("foo", "bar");
      client.get("foo");
      client.get("foo"); // Cache hit

      System.out.println("Cache size: " + cache.getSize()); // 1
      System.out.println(cache.getStats().toString());

      //Let's change the value of "foo" to invalidate the value stored in the local cache
      client.mset("foo", "new_value", "ignore_me:1", "another_value");

      Thread.sleep(1000); // wait for the cache invalidation to happen

      System.out.println(client.get("foo")); // Cache miss
      System.out.println(cache.getStats().toString());

      client.get("ignore_me:1"); // Client will ignore this key

      System.out.println("Cache size: " + cache.getSize()); // still 1

      // check the cache stats
      System.out.println(cache.getStats().toString());

    } catch (InterruptedException e) {
      throw new RuntimeException(e);
    }
  }

  private static CacheConfig getCacheConfig() {

    // This is a simple cacheable implementation that ignores keys starting with "ignore_me"
    Cacheable cacheable = new DefaultCacheable() {

      final String IGNORE_PREFIX = "ignore_me";

      @Override
      public boolean isCacheable(ProtocolCommand command, List<Object> keys) {
        // assuming we'll only execute methods with string keys
        List<String> stringKeys = keys.stream()
            .filter(obj -> obj instanceof String)
            .map(obj -> (String) obj)
            .collect(Collectors.toList());

        for (String key : stringKeys) {
          if (key.startsWith(IGNORE_PREFIX)) {
            return false;
          }
        }

        return isDefaultCacheableCommand(command);
      }
    };

    // Create a cache with a maximum size of 10000 entries
    return CacheConfig.builder()
        .maxSize(10000)
        .cacheable(cacheable)
        .build();
  }
}

It is possible to limit or ignore commands or keys for client-side caching. The getCacheConfig method presented above provides an example of how to achieve that.