Adding Compression to Spring Data Redis with LettuceConnectionFactory

Question

I see Lettuce can do compression for Redis serialized objects: https://lettuce.io/core/release/reference/#codecs.compression

Any way to set this config within Spring Boot Data LettuceConnectionFactory or in some other bean? I've seen this question asked here as well: https://github.com/lettuce-io/lettuce-core/issues/633

I'd like to compress all serialized objects being sent to Redis to reduce network traffic between boxes.

Thanks

Answer 1

I ended up solving it the following way.

1. Create a RedisTemplate Spring Bean. This allows us to set a custom serializer.

    @Bean
    public RedisTemplate<Object, Object> redisTemplate(LettuceConnectionFactory connectionFactory) {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);

        // Set a custom serializer that will compress/decompress data to/from redis
        RedisSerializerGzip serializerGzip = new RedisSerializerGzip();
        template.setValueSerializer(serializerGzip);
        template.setHashValueSerializer(serializerGzip);
        return template;
    }

2. Create a custom serializer. I decided to extend JdkSerializationRedisSerializer since that's what Spring was using by default for Redis. I added a compress/decompress in each respected method and use the super class serialization code.

public class RedisSerializerGzip extends JdkSerializationRedisSerializer {

    @Override
    public Object deserialize(byte[] bytes) {
        return super.deserialize(decompress(bytes));
    }

    @Override
    public byte[] serialize(Object object) {
        return compress(super.serialize(object));
    }


    ////////////////////////
    // Helpers
    ////////////////////////
    private byte[] compress(byte[] content) {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        try (GZIPOutputStream gzipOutputStream = new GZIPOutputStream(byteArrayOutputStream)) {
            gzipOutputStream.write(content);
        } catch (IOException e) {
            throw new SerializationException("Unable to compress data", e);
        }
        return byteArrayOutputStream.toByteArray();
    }

    private byte[] decompress(byte[] contentBytes) {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try {
            IOUtils.copy(new GZIPInputStream(new ByteArrayInputStream(contentBytes)), out);
        } catch (IOException e) {
            throw new SerializationException("Unable to decompress data", e);
        }
        return out.toByteArray();
    }

}

3. Use spring dependency injection for the RedisTemplate Bean.