Tag: cache

From Hell To Heaven: Safeguarding your application – Part 1

Have you ever wondered how to safeguard your application when using the database and a cache like Redis? What if one of them is down? What should we do? These are questions that every developer should ask themselves when building an API that needs to be reliable 24/7.

In this guide, we will be configuring a cache error handler that will cover every scenario where Spring Cache annotations are used.

Building the cache error handler

The reason to build a custom error handler is simple: we want the application working even though the cache is down.

We will need to do two things: Implement the CacheErrorHandler interface and registering into our application. Below is the implementation of our class:

package com.jerieshandal.api.config; import lombok.extern.slf4j.Slf4j; import org.springframework.cache.Cache; import org.springframework.cache.interceptor.CacheErrorHandler; @Slf4j public class CustomCacheErrorHandler implements CacheErrorHandler { @Override public void handleCacheGetError(RuntimeException e, Cache cache, Object o) { log.error(e.getMessage(), e); } @Override public void handleCachePutError(RuntimeException e, Cache cache, Object o, Object o1) { log.error(e.getMessage(), e); } @Override public void handleCacheEvictError(RuntimeException e, Cache cache, Object o) { log.error(e.getMessage(), e); } @Override public void handleCacheClearError(RuntimeException e, Cache cache) { log.error(e.getMessage(), e); } } Read more...

From Hell To Heaven: Increase app’s performance with Redis

Welcome to my new series “From Hell To Heaven“. These series will be about different cases of programmers dealing with issues that anyone can find in a typical day. In this first post, we will be implementing Redis as a second level cache layer using Spring Boot.

Introduction

I have been working on a couple of projects and encountered several performance issues. This issue relied mostly on reading the same data multiple times in the same endpoint. Using second layer cache is a common solution to this issue and that’s what we are going to do today! You will see how easy it will be to integrate Redis as a cache layer using Spring boot.

What is Redis?

Redis is an in-memory data structure used as a database or cache. Being in-memory provides a huge benefit in performance; reading and writing are way faster than persisting to disk. It also provides a way of persisting data utilizing RDB and AOF, making it perfect to keep the data when restarting the server.

Implementation

Dependencies and Configuration

Your project will need spring-boot-starter-data-redis dependency in order to work properly with Spring Boot. Then we need to configure Redis and the cache, which is fairly easy to do it by taking advantage of Spring Boot’s auto configuration as shown in the following segment:

spring.redis.url=redis://user:password@example.com:6379 spring.redis.host=localhost # Redis server host. spring.redis.password= # Login password of the redis server. Leave empty if no password spring.redis.port=6379 # Redis server port. spring.cache.type=redis spring.cache.redis.cache-null-values=true # Allow caching null values. spring.cache.redis.key-prefix=project_key # Key prefix. spring.cache.redis.time-to-live=60000ms # Entry expiration. By default the entries never expire. spring.cache.redis.use-key-prefix=true # Whether to use the key prefix when writing to Redis. Read more...