Redis客户端连接池耗尽的常见问题及优化配置,涵盖监控预警、关联技术整合等领域

// 错误示例：忘记归还连接的典型写法（Spring Boot + Lettuce）
public void updateProductStock(String productId) {
    RedisConnection connection = redisTemplate.getConnectionFactory().getConnection();
    try {
        connection.incrBy(("stock:" + productId).getBytes(), -1);
    } finally {
        // 致命错误：缺少connection.close()
    }
}

// 正确写法：使用try-with-resources自动关闭
public void updateProductStock(String productId) {
    try (RedisConnection connection = redisTemplate.getConnectionFactory().getConnection()) {
        connection.incrBy(("stock:" + productId).getBytes(), -1);
    }
}

# application.yml危险配置示例
spring:
  redis:
    lettuce:
      pool:
        max-active: 8  # 生产环境设这么小等于自杀
        max-idle: 4
        min-idle: 0

# 优化后的生产配置
spring:
  redis:
    lettuce:
      pool:
        max-active: 100      # 根据压测结果调整
        max-idle: 50
        min-idle: 20         # 保持基础水位
        max-wait: 200ms      # 等待超时时间

// 应用启动时连接池预热（Spring Boot示例）
@PostConstruct
public void initRedisPool() {
    RedisConnectionFactory factory = redisTemplate.getConnectionFactory();
    for (int i = 0; i < factory.getPool().getMaxIdle(); i++) {
        try (RedisConnection conn = factory.getConnection()) {
            // 仅建立连接不执行操作
        }
    }
}

# 危险操作：Keys命令导致全库扫描
127.0.0.1:6379> KEYS order_202307*
(3.21s)

// 使用SCAN命令分批次处理（Spring Data Redis实现）
public Set<String> findOrderKeys(String pattern) {
    Set<String> keys = new HashSet<>();
    RedisConnection connection = null;
    try {
        connection = redisTemplate.getConnectionFactory().getConnection();
        Cursor<byte[]> cursor = connection.scan(ScanOptions.scanOptions()
                .match(pattern)
                .count(100)  // 每次扫描100个
                .build());
        while (cursor.hasNext()) {
            keys.add(new String(cursor.next()));
        }
    } finally {
        if (connection != null) connection.close();
    }
    return keys;
}

2023-07-15 14:23:51 ERROR o.s.d.redis.core.RedisConnectionUtils - Could not get a resource from the pool

spring:
  redis:
    timeout: 1000     # 单位毫秒
    lettuce:
      shutdown-timeout: 500

最大连接数 = (平均业务耗时(ms) × QPS) / 1000 + 缓冲系数(建议20%)

// 连接有效性检测配置（Lettuce特有）
public LettuceClientConfiguration lettuceConfig() {
    return LettucePoolingClientConfiguration.builder()
            .poolConfig(genericObjectPoolConfig())
            .clientOptions(ClientOptions.builder()
                    .autoReconnect(true)
                    .publishOnScheduler(true)
                    .socketOptions(SocketOptions.builder()
                            .connectTimeout(Duration.ofSeconds(1))
                            .build())
                    .build())
            .build();
}

# Redis服务端监控命令
redis-cli info clients
redis-cli info stats

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: order-service
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: order-service
  minReplicas: 3
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: redis_connections_active
      target:
        type: Utilization
        averageUtilization: 80

// 批量操作提升10倍性能
List<Object> results = redisTemplate.executePipelined((RedisCallback<Object>) connection -> {
    for (int i = 0; i < 1000; i++) {
        connection.stringCommands().set(("key"+i).getBytes(), ("value"+i).getBytes());
    }
    return null;
});

// 使用RedisTemplate的execute方法自动管理连接
redisTemplate.execute((RedisCallback<Void>) connection -> {
    connection.stringCommands().set("session:1001".getBytes(), "data".getBytes());
    connection.expire("session:1001".getBytes(), 3600);
    return null;
});

spring:
  redis:
    lettuce:
      pool:
        max-active: 500
        max-idle: 300
        min-idle: 100
        time-between-eviction-runs: 60s

// 多数据源连接池配置
@Configuration
public class RedisConfig {
    @Bean(name = "deviceRedis")
    public RedisTemplate<String, Object> deviceRedisTemplate() {
        // 设备专用连接池配置
    }

    @Bean(name = "metaRedis")
    public RedisTemplate<String, Object> metaRedisTemplate() {
        // 元数据专用连接池配置
    }
}