我在我的应用程序中使用 Redis 作为缓存。我经常使用缓存来获取数据。我使用的是 spring-boot 版本 1.5.9、spring-data-redis 1.8.9、jedis 2.9.0 和 commons-pool 1.6。

我听不懂

1. 为什么不关闭连接？
2. 为什么无法从池中获取连接？

这是我正在使用的 Redis 的配置:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
import redis.clients.jedis.JedisPoolConfig;

import java.time.Duration;

@Configuration
public class ApplicationConfiguration {

    @Value("${spring.redis.host}")
    private String REDIS_HOST;

    @Value("${spring.redis.port}")
    private int REDIS_PORT;

    @Value("${spring.redis.database}")
    private int REDIS_DATABASE;

    @Value("${spring.redis.pool.max-active}")
    private int REDIS_POOL_MAX_ACTIVE;

    @Value("${spring.redis.pool.max-idle}")
    private int REDIS_POOL_MAX_IDLE;

    @Value("${spring.redis.pool.min-idle}")
    private int REDIS_POOL_MIN_IDLE;

    @Value("${spring.redis.pool.max-wait}")
    private long REDIS_POOL_TIMEOUT;

    @Value("${spring.redis.timeout}")
    private int REDIS_TIMEOUT;

    @Bean
    public JedisConnectionFactory jedisConnectionFactory() {
        JedisPoolConfig poolConfig = new JedisPoolConfig();
        //Maximum number of active connections that can be allocated from this pool at the same time
        poolConfig.setMaxTotal(REDIS_POOL_MAX_ACTIVE);
        //Number of connections to Redis that just sit there and do nothing
        poolConfig.setMaxIdle(REDIS_POOL_MAX_IDLE);
        //Minimum number of idle connections to Redis - these can be seen as always open and ready to serve
        poolConfig.setMinIdle(REDIS_POOL_MIN_IDLE);
        //The maximum number of milliseconds that the pool will wait (when there are no available connections) for a connection to be returned before throwing an exception
        poolConfig.setMaxWaitMillis(REDIS_POOL_TIMEOUT);
        //The minimum amount of time an object may sit idle in the pool before it is eligible for eviction by the idle object evictor
        poolConfig.setMinEvictableIdleTimeMillis(Duration.ofSeconds(60).toMillis());
        //The minimum amount of time a connection may sit idle in the pool before it is eligible for eviction by the idle connection evictor
        poolConfig.setSoftMinEvictableIdleTimeMillis(Duration.ofSeconds(10).toMillis());
        //Idle connection checking period
        poolConfig.setTimeBetweenEvictionRunsMillis(Duration.ofSeconds(5).toMillis());
        //Maximum number of connections to test in each idle check
        poolConfig.setNumTestsPerEvictionRun(3);
        //Tests whether connection is dead when connection retrieval method is called
        poolConfig.setTestOnBorrow(true);
        //Tests whether connection is dead when returning a connection to the pool
        poolConfig.setTestOnReturn(true);
        //Tests whether connections are dead during idle periods
        poolConfig.setTestWhileIdle(true);
        poolConfig.setBlockWhenExhausted(true);

        JedisConnectionFactory connectionFactory = new JedisConnectionFactory(poolConfig);
        connectionFactory.setUsePool(true);
        connectionFactory.setHostName(REDIS_HOST);
        connectionFactory.setPort(REDIS_PORT);
        connectionFactory.setDatabase(REDIS_DATABASE);
        connectionFactory.setTimeout(REDIS_TIMEOUT);

        return connectionFactory;
    }

    @Bean
    public LoggingRedisTemplate stringRedisTemplate(@Autowired JedisConnectionFactory jedisConnectionFactory) {
        LoggingRedisTemplate stringRedisTemplate = new LoggingRedisTemplate(jedisConnectionFactory);
        stringRedisTemplate.setEnableTransactionSupport(true);
        return stringRedisTemplate;
    }

    @Bean
    public RedisCacheManager cacheManager(@Autowired StringRedisTemplate stringRedisTemplate) {
        RedisCacheManager cacheManager = new RedisCacheManager(stringRedisTemplate);
        cacheManager.setUsePrefix(true);
        return cacheManager;
    }

}

然后我使用服务来访问数据:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.connection.StringRedisConnection;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.types.RedisClientInfo;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public class RedisService {

    @Autowired
    private LoggingRedisTemplate stringRedisTemplate;

    public String getStringValue(final String key) {
//        return stringRedisTemplate.opsForValue().get(key);
        return readValueWithCallBack(key);
    }

    public void setStringValue(final String key, final String value) {
//        stringRedisTemplate.opsForValue().setIfAbsent(key, value);
        writeValueWithCallBack(key,value);
    }

    public void removeStringValue(final String key) {
//        stringRedisTemplate.delete(key);
        removeValueWithCallback(key);
    }


    public Long removeValueWithCallback(final String key){

        return (Long) stringRedisTemplate.execute( new RedisCallback<Object>() {
            @Override
            public Object doInRedis(RedisConnection connection) throws DataAccessException {
                StringRedisConnection stringRedisConnection = (StringRedisConnection) connection;
                stringRedisConnection.multi();
                Long deletedKeysCount = stringRedisConnection.del(key);
                stringRedisConnection.exec();
                stringRedisConnection.close();
                return deletedKeysCount;
            }
        });
    }

    public String readValueWithCallBack(final String key){

        return (String) stringRedisTemplate.execute( new RedisCallback<Object>() {
            @Override
            public Object doInRedis(RedisConnection connection) throws DataAccessException {
                StringRedisConnection stringRedisConnection = (StringRedisConnection) connection;
                String value = stringRedisConnection.get(key);
                List<RedisClientInfo> redisClientInfos = stringRedisConnection.getClientList();
                stringRedisConnection.close();
                return value;
            }
        });
    }

    public void writeValueWithCallBack(final String key, final String value){

        stringRedisTemplate.execute( new RedisCallback<Object>() {
            @Override
            public Object doInRedis(RedisConnection connection) throws DataAccessException {
                StringRedisConnection stringRedisConnection = (StringRedisConnection) connection;
                stringRedisConnection.multi();
                stringRedisConnection.set(key,value);
                stringRedisConnection.exec();
                stringRedisConnection.close();
                return null;
            }
        });
    }
}

这是我创建的 Redis 模板，用于避免异常并在异常发生后正常进行下一步:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.SessionCallback;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 *
 * An extension of RedisTemplate that logs exceptions instead of letting them propagate.
 * If the Redis server is unavailable, cache operations are always a "miss" and data is fetched from the database.
 */
@Component
public class LoggingRedisTemplate extends StringRedisTemplate {

    private static final Logger logger = LoggerFactory.getLogger(LoggingRedisTemplate.class);

    public LoggingRedisTemplate(RedisConnectionFactory connectionFactory) {
        super(connectionFactory);
    }

    @Override
    public <T> T execute(final RedisCallback<T> action, final boolean exposeConnection, final boolean pipeline) {
        try {
            return super.execute(action, exposeConnection, pipeline);
        }
        catch(final Throwable t) {
            logger.warn("Error executing cache operation: {}", t.getMessage());
            return null;
        }
    }


    @Override
    public <T> T execute(final RedisScript<T> script, final List<String> keys, final Object... args) {
        try {
            return super.execute(script, keys, args);
        }
        catch(final Throwable t) {
            logger.warn("Error executing cache operation: {}", t.getMessage());
            return null;
        }
    }


    @Override
    public <T> T execute(final RedisScript<T> script, final RedisSerializer<?> argsSerializer, final RedisSerializer<T> resultSerializer, final List<String> keys, final Object... args) {
        try {
            return super.execute(script, argsSerializer, resultSerializer, keys, args);
        }
        catch(final Throwable t) {
            logger.warn("Error executing cache operation: {}", t.getMessage());
            return null;
        }
    }


    @Override
    public <T> T execute(final SessionCallback<T> session) {
        try {
            return super.execute(session);
        }
        catch(final Throwable t) {
            logger.warn("Error executing cache operation: {}", t.getMessage());
            return null;
        }
    }
}

我从这里引用了这个日志记录模板:https://stackoverflow.com/a/26666102/8499307

我在 application.properties 中使用这个配置

spring.data.redis.repositories.enabled=false

spring.cache.type=redis
spring.redis.host=localhost
spring.redis.port=6379
spring.redis.database=0
spring.redis.pool.max-active=256
spring.redis.pool.max-idle=12
spring.redis.pool.max-wait=100
spring.redis.pool.min-idle=6
spring.redis.timeout=100

我之前使用 stringRedisTemplate.opsForValue().get(key) 来获取数据，但在一些帖子中，他们建议使用回调来正确关闭连接，但这也没有用。

如有其他需要请评论。

最佳答案

问题已解决:)

我只在 RedisService 中进行了更改，现在它运行得很好。一旦读/写/删除操作完成，我已经完成更改以关闭连接。

您可以查看下面的代码:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.RedisConnectionFailureException;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

@Component
public class RedisService {

    @Autowired
    private LoggingRedisTemplate stringRedisTemplate;

    private static final Logger logger = LoggerFactory.getLogger(RedisService.class);

    public String getStringValue(final String key) {
        String data = stringRedisTemplate.opsForValue().get(key);

        try {
            closeConnection(stringRedisTemplate);
        }catch (RedisConnectionFailureException e){
            closeClients(stringRedisTemplate);
        }finally {
            closeConnection(stringRedisTemplate);
        }
        return data;
    }

    public void setStringValue(final String key, final String value) {
        stringRedisTemplate.opsForValue().setIfAbsent(key, value);

        try {
            closeConnection(stringRedisTemplate);
        }catch (RedisConnectionFailureException e){
            closeClients(stringRedisTemplate);
        }finally {
            closeConnection(stringRedisTemplate);
        }
    }

    public void removeStringValue(final String key) {
        stringRedisTemplate.delete(key);

        try {
            closeConnection(stringRedisTemplate);
        }catch (RedisConnectionFailureException e){
            closeClients(stringRedisTemplate);
        }finally {
            closeConnection(stringRedisTemplate);
        }
    }

    private void closeConnection(StringRedisTemplate stringRedisTemplate){
        try {
            JedisConnectionFactory connectionFactory = (JedisConnectionFactory) stringRedisTemplate.getConnectionFactory();
            connectionFactory.getConnection().close();
            connectionFactory.destroy();
        }catch (RedisConnectionFailureException e){
            logger.info("Connection closed already");
        }
    }

    private void closeClients(LoggingRedisTemplate stringRedisTemplate){
        try {
            if(null != stringRedisTemplate.getClientList()){
                stringRedisTemplate.getClientList().remove(0);
                stringRedisTemplate.getClientList().remove(1);
                stringRedisTemplate.getClientList().forEach(redisClientInfo -> {
                    String address = redisClientInfo.getAddressPort();
                    if(null != address){
                        String [] addressList = address.split(":");
                        stringRedisTemplate.killClient(addressList[0],Integer.parseInt(addressList[1]));
                    }
                });
            }
        }catch (Exception e){
            logger.warn("Unable to close client connections, ", e);
        }
    }

}

我希望，它也能帮助其他人:)

关于Spring Boot - Redis 缓存连接池在几次请求后耗尽，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50925150/