Lettuce 和 Jedis 的都是连接Redis Server的客户端程序。Jedis在实现上是直连redis server，多线程环境下非线程安全（即多个线程对一个连接实例操作，是线程不安全的），除非使用连接池，为每个Jedis实例增加物理连接。Lettuce基于Netty的连接实例（StatefulRedisConnection），可以在多个线程间并发访问，且线程安全，满足多线程环境下的并发访问（即多个线程公用一个连接实例，线程安全），同时它是可伸缩的设计，一个连接实例不够的情况也可以按需增加连接实例。
添加依赖
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-jdbc'
implementation 'org.springframework.boot:spring-boot-starter-data-redis'
implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.mybatis.spring.boot:mybatis-spring-boot-starter:2.1.3'
//lettuce依赖commons-pool2
compile group: 'org.apache.commons', name: 'commons-pool2', version: '2.6.2'
runtimeOnly 'mysql:mysql-connector-java'
compileOnly 'org.projectlombok:lombok'
annotationProcessor 'org.projectlombok:lombok'
testImplementation('org.springframework.boot:spring-boot-starter-test') {
exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
}
compile('org.springframework.boot:spring-boot-starter-cache')
}
application.properties 添加redis连接信息
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/mytest?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8 spring.datasource.username=root spring.datasource.password=123456 server.port=8945 #redis数据库默认使用db0 spring.redis.database=2 spring.redis.password= spring.redis.port=6379 spring.redis.host=127.0.0.1 # 连接超时时间 spring.redis.timeout=5000 # 连接池最大连接数（使用负值表示没有限制） spring.redis.lettuce.pool.max-active=3 # 连接池中的最小空闲连接 spring.redis.lettuce.pool.min-idle=2 # 连接池中的最大空闲连接 spring.redis.lettuce.pool.max-idle=3 # 连接池最大阻塞等待时间（使用负值表示没有限制） spring.redis.lettuce.pool.max-wait=-1 #在关闭客户端连接之前等待任务处理完成的最长时间，在这之后，无论任务是否执行完成，都会被执行器关闭，默认100ms spring.redis.lettuce.shutdown-timeout=100 #是否缓存空值 spring.cache.redis.cache-null-values=false
编写配置类
package org.example.base.config;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.jsontype.impl.LaissezFaireSubTypeValidator;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisPassword;
import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceClientConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import java.time.Duration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* @author l
* @date Created in 2020/11/3 10:51
*/
@Configuration
@EnableCaching
public class RedisConfig {
@Value("${spring.redis.database}")
private int database;
@Value("${spring.redis.host}")
private String host;
@Value("${spring.redis.password}")
private String password;
@Value("${spring.redis.port}")
private int port;
@Value("${spring.redis.timeout}")
private long timeout;
@Value("${spring.redis.lettuce.shutdown-timeout}")
private long shutDownTimeout;
@Value("${spring.redis.lettuce.pool.max-idle}")
private int maxIdle;
@Value("${spring.redis.lettuce.pool.min-idle}")
private int minIdle;
@Value("${spring.redis.lettuce.pool.max-active}")
private int maxActive;
@Value("${spring.redis.lettuce.pool.max-wait}")
private long maxWait;
Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
@Bean
public LettuceConnectionFactory lettuceConnectionFactory() {
GenericObjectPoolConfig genericObjectPoolConfig = new GenericObjectPoolConfig();
genericObjectPoolConfig.setMaxIdle(maxIdle);
genericObjectPoolConfig.setMinIdle(minIdle);
genericObjectPoolConfig.setMaxTotal(maxActive);
genericObjectPoolConfig.setMaxWaitMillis(maxWait);
genericObjectPoolConfig.setTimeBetweenEvictionRunsMillis(100);
RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
redisStandaloneConfiguration.setDatabase(database);
redisStandaloneConfiguration.setHostName(host);
redisStandaloneConfiguration.setPort(port);
redisStandaloneConfiguration.setPassword(RedisPassword.of(password));
LettuceClientConfiguration clientConfig = LettucePoolingClientConfiguration.builder()
.commandTimeout(Duration.ofMillis(timeout))
.shutdownTimeout(Duration.ofMillis(shutDownTimeout))
.poolConfig(genericObjectPoolConfig)
.build();
LettuceConnectionFactory factory = new LettuceConnectionFactory(redisStandaloneConfiguration, clientConfig);
// factory.setShareNativeConnection(true);
// factory.setValidateConnection(false);
return factory;
}
@Bean
public RedisTemplate<String, Object> redisTemplate(LettuceConnectionFactory lettuceConnectionFactory) {
RedisTemplate<String, Object> template = new RedisTemplate<>();
template.setConnectionFactory(lettuceConnectionFactory);
//使用Jackson2JsonRedisSerializer替换默认的JdkSerializationRedisSerializer来序列化和反序列化redis的value值
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
mapper.activateDefaultTyping(LaissezFaireSubTypeValidator.instance,
ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
jackson2JsonRedisSerializer.setObjectMapper(mapper);
StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
//key采用String的序列化方式
template.setKeySerializer(stringRedisSerializer);
// hash的key也采用String的序列化方式
template.setHashKeySerializer(stringRedisSerializer);
// value序列化方式采用jackson
template.setValueSerializer(jackson2JsonRedisSerializer);
// hash的value序列化方式采用jackson
template.setHashValueSerializer(jackson2JsonRedisSerializer);
template.afterPropertiesSet();
return template;
}
@Bean("redisCacheManager")
@Primary
public CacheManager cacheManager( LettuceConnectionFactory lettuceConnectionFactory) {
RedisSerializer<String> redisSerializer = new StringRedisSerializer();
//解决查询缓存转换异常的问题
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
mapper.activateDefaultTyping(LaissezFaireSubTypeValidator.instance,
ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
jackson2JsonRedisSerializer.setObjectMapper(mapper);
// 配置1 ,
RedisCacheConfiguration config1 = RedisCacheConfiguration.defaultCacheConfig()
//缓存失效时间
.entryTtl(Duration.ofSeconds(30))
//key序列化方式
.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
//value序列化方式
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
//不允许缓存null值
.disableCachingNullValues();
//配置2 ,
RedisCacheConfiguration config2 = RedisCacheConfiguration.defaultCacheConfig()
.entryTtl(Duration.ofMinutes(1000))
.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
.disableCachingNullValues();
//设置一个初始化的缓存空间set集合
Set<String> cacheNames = new HashSet<>();
cacheNames.add("my-redis-cache1");
cacheNames.add("my-redis-cache2");
//对每个缓存空间应用不同的配置
Map<String, RedisCacheConfiguration> configurationMap = new HashMap<>(3);
configurationMap.put("my-redis-cache1", config1);
configurationMap.put("my-redis-cache2", config2);
return RedisCacheManager.builder(lettuceConnectionFactory)
//默认缓存配置
.cacheDefaults(config1)
//初始化缓存空间
.initialCacheNames(cacheNames)
//初始化缓存配置
.withInitialCacheConfigurations(configurationMap).build();
}
}
编写service层
package org.example.base.service.impl;
import org.example.base.bean.Animal;
import org.example.base.service.AnimalService;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
/**
* @author l
* @date Created in 2020/11/4 17:33
*/
@Service
@CacheConfig(cacheNames = "my-redis-cache1", cacheManager = "redisCacheManager")
public class AnimalServiceImpl implements AnimalService {
@Override
@Cacheable(key = "#id",sync = true)
public Animal getAnimal(Integer id) {
System.out.println("操作数据库，返回Animal");
return new Animal(110, "cat", "fish");
}
/**
* 使用@CachePut注解的方法，一定要有返回值，该注解声明的方法缓存的是方法的返回结果。
* it always causes the
* method to be invoked and its result to be stored in the associated cache
**/
@Override
@CachePut(key = "#animal.getId()")
public Animal setAnimal(Animal animal) {
System.out.println("存入数据库");
return animal;
}
@Override
@CacheEvict(key = "#id")
public void deleteAnimal(Integer id) {
System.out.println("删除数据库中animal");
}
@Override
@CachePut(key = "#animal.getId()")
public Animal updateAnimal(Animal animal) {
System.out.println("修改animal,并存入数据库");
return animal;
}
}
编写controller层
package org.example.base.controller;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiParam;
import lombok.extern.slf4j.Slf4j;
import org.example.base.bean.Animal;
import org.example.base.bean.User;
import org.example.base.service.AnimalService;
import org.example.base.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.cache.Cache;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
/**
* @author l
* @date Created in 2020/10/23 15:46
*/
@Controller
@RequestMapping("/user")
@Slf4j
public class UserController {
private AnimalService animalService;
@Autowired
public UserController(AnimalService animalService) {
this.animalService = animalService;
}
@GetMapping("/queryAnimal")
@ResponseBody
public Animal queryAnimal(@RequestParam(value = "ID") Integer ID) {
Animal animal = animalService.getAnimal(ID);
log.info("animal " + animal.toString());
return animal;
}
}
配置jemeter
启动jemeter ,查看当前redis的客户端连接数
当前springboot lettuce连接池中有三个连接 加上当前查询窗口的连接，共计4个socket连接。
jemeter 运行2分钟后显示，平均响应时间为239，吞吐量为4158.2/sec
注释掉 RedisConfig 类中
genericObjectPoolConfig.setTimeBetweenEvictionRunsMillis(100);
这行代码，重新启动项目，用jemeter进行压测接口。
查看当前redis的客户端连接数
可以看出连接池没有生效，经过两分钟压测后显示平均响应时间为241，吞吐量为4139.2/sec
，接口性能相比于使用lettuce连接池中多个连接，略有下降。 总结 要想使lettuce连接池生效，即使用多个redis物理连接。这行设置不能缺少
genericObjectPoolConfig.setTimeBetweenEvictionRunsMillis(100); 这个设置是，每隔多少毫秒，空闲线程驱逐器关闭多余的空闲连接，且保持最少空闲连接可用，这个值最好设置大一点，否者影响性能。同时 genericObjectPoolConfig.setMinIdle(minIdle); 中minldle值要大于0。
lettuce连接池属性timeBetweenEvictionRunsMillis如果不设置 默认是 -1，当该属性值为负值时，lettuce连接池要维护的最小空闲连接数的目标minIdle就不会生效 。源码中的解释如下：
/** * Target for the minimum number of idle connections to maintain in the pool. This * setting only has an effect if both it and time between eviction runs are * positive. */ private int minIdle = 0;
factory.setShareNativeConnection(true)，shareNativeConnection 这个属性默认是true,允许多个连接公用一个物理连接。如果设置false ,每一个连接的操作都会开启和关闭socket连接。如果设置为false,会导致性能下降，本人测试过了。源码中解释如下：
/**
* Enables multiple {@link LettuceConnection}s to share a single native connection. If set to {@literal false}, every
* operation on {@link LettuceConnection} will open and close a socket.
*
* @param shareNativeConnection enable connection sharing.
*/
public void setShareNativeConnection(boolean shareNativeConnection) {
this.shareNativeConnection = shareNativeConnection;
}
-factory.setValidateConnection(false)， validateConnection这个属性是每次获取连接时，校验连接是否可用。默认false,不去校验。默认情况下，lettuce开启一个共享的物理连接，是一个长连接，所以默认情况下是不会校验连接是否可用的。如果设置true,会导致性能下降。
