Redis command timed out; nested exception is io.lettuce.core.RedisCommandTimeoutException: Command timed out after 15 second(s) at

### Spring Data Redis 中 Lettuce 报 QueryTimeoutException 的分析与解决方案 当在 Windows 上部署 Redis 并使用 Spring Data Redis 和 Lettuce 驱动时，如果遇到 `QueryTimeoutException` 或者 `RedisCommandTimeoutException`，这通常表明客户端请求未能在指定的时间内完成。以下是可能的原因以及对应的解决方案。 #### 1. 调整超时配置 默认情况下，Lettuce 客户端会设置一个较短的命令执行超时时间（通常是 5 秒）。可以通过修改 `spring.redis.timeout` 参数来增加这个超时时间。例如： ```properties spring.redis.timeout=10000 # 设置为 10 秒 ``` 此外，还可以通过自定义 Lettuce 的连接工厂进一步调整超时参数[^2]： ```java import org.springframework.context.annotation.Bean; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.connection.lettuce.LettuceClientConfiguration; import org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration; import io.lettuce.core.ClientOptions; @Bean public RedisConnectionFactory redisConnectionFactory() { LettuceClientConfiguration clientConfig = LettucePoolingClientConfiguration.builder() .commandTimeout(Duration.ofSeconds(10)) // 命令超时时间为 10 秒 .clientOptions(ClientOptions.builder().autoReconnect(true).build()) // 启用自动重连 .build(); return new LettuceConnectionProvider(clientConfig); } ``` #### 2. 检查网络延迟和带宽 Windows 环境下运行 Redis 可能存在较高的网络延迟或者较低的吞吐量。建议测试本地主机到 Redis 实例之间的网络性能。可以使用工具如 `ping` 测试延迟，或使用 `iperf` 工具评估带宽。 #### 3. 数据库负载过高 如果 Redis 正处于高负载状态，则可能会导致某些操作无法及时响应。此时应监控 Redis 性能指标，比如 CPU 使用率、内存占用情况等。可以启用慢查询日志功能以定位耗时较长的操作： ```bash config set slowlog-log-slower-than 10000 # 记录超过 10ms 的查询 config set slowlog-max-len 1024 # 设定最大记录数 slowlog get # 查看慢查询日志 ``` #### 4. Windows 特有的文件句柄限制 由于 Windows 对于单进程打开文件数量有限制，默认值可能不足以支持大量并发连接。可以通过注册表编辑器提高该限制值[^3]: - 打开 Regedit； - 导航至路径：HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management； - 创建名为 PoolTagOrder 的字符串键值项并赋值为 "File"； - 修改 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters 下的最大工作线程数目 MaxWorkItems。 #### 5. 升级依赖版本 确保使用的 Spring Boot 和 Spring Data Redis 是最新稳定版，因为旧版本可能存在已知 bug。同时也要确认所选 Lettuce 库与其兼容性良好。 --- ### 示例代码片段 下面是一个完整的 Java 配置类示例，用于定制化 Lettuce 连接行为： ```java @Configuration public class RedisConfig { @Bean public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<String, Object> template = new RedisTemplate<>(); template.setKeySerializer(new StringRedisSerializer()); template.setValueSerializer(new GenericJackson2JsonRedisSerializer()); LettucePoolingClientConfiguration config = LettucePoolingClientConfiguration.builder() .commandTimeout(Duration.ofSeconds(15)) .shutdownTimeout(Duration.ZERO) .build(); template.setConnectionFactory(factory); return template; } } ``` --- ###

This error message indicates that a Redis command has taken too long to execute and has timed out. The timeout duration in this case is 12 seconds. There are a few potential reasons why this error might occur: 1. The Redis server is overloaded or experiencing high traffic, causing commands to take longer than usual to execute. This can be resolved by optimizing the Redis server and/or increasing its resources. 2. The command being executed is particularly complex or resource-intensive, causing it to take longer than the timeout duration. In this case, you may need to optimize the command or increase the timeout duration to accommodate it. 3. There is a network issue or connectivity problem between the client and the Redis server, causing delays or timeouts. You may need to troubleshoot your network infrastructure to resolve this issue. To resolve this error, you can try the following: - Increase the timeout duration for Redis commands to allow for longer execution times. - Optimize the Redis server to improve performance and reduce command execution times. - Troubleshoot any network or connectivity issues that may be causing delays or timeouts.