protected static int getHystrixTimeout(IClientConfig config, String commandKey) {
	int ribbonTimeout = getRibbonTimeout(config, commandKey);
	DynamicPropertyFactory dynamicPropertyFactory = DynamicPropertyFactory.getInstance();
	
	// 获取默认的hytrix超时时间
	int defaultHystrixTimeout = dynamicPropertyFactory.getIntProperty("hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds",
		0).get();
	// 获取详细处事的hytrix超时时间，昆山软件开发，这里应该是hystrix.command.foo.execution.isolation.thread.timeoutInMilliseconds
	int commandHystrixTimeout = dynamicPropertyFactory.getIntProperty("hystrix.command." + commandKey + ".execution.isolation.thread.timeoutInMilliseconds",
		0).get();
	int hystrixTimeout;
	// hystrixTimeout的优先级是 详细处事的hytrix超时时间 > 默认的hytrix超时时间 > ribbon超时时间
	if(commandHystrixTimeout > 0) {
		hystrixTimeout = commandHystrixTimeout;
	}
	else if(defaultHystrixTimeout > 0) {
		hystrixTimeout = defaultHystrixTimeout;
	} else {
		hystrixTimeout = ribbonTimeout;
	}
	// 假如默认的可能详细处事的hytrix超时时间小于ribbon超时时间就会告诫
	if(hystrixTimeout < ribbonTimeout) {
		LOGGER.warn("The Hystrix timeout of " + hystrixTimeout + "ms for the command " + commandKey +
			" is set lower than the combination of the Ribbon read and connect timeout, " + ribbonTimeout + "ms.");
	}
	return hystrixTimeout;
}

紧接着，看一下我们的设置是什么

hystrix:
  command:
    default:
      execution:
        isolation:
          thread:
            timeoutInMilliseconds: 60000
            
ribbon:
  ReadTimeout: 50000
  ConnectTimeout: 50000
  MaxAutoRetries: 0
  MaxAutoRetriesNextServer: 1

ribbon超时时间

这里ribbon的超时时间是50000ms，那么为什么log中写的ribbon时间是200000ms?

继承阐明源码：

protected static int getRibbonTimeout(IClientConfig config, String commandKey) {
	int ribbonTimeout;
	// 这是较量异常的环境，不说
	if (config == null) {
		ribbonTimeout = RibbonClientConfiguration.DEFAULT_READ_TIMEOUT + RibbonClientConfiguration.DEFAULT_CONNECT_TIMEOUT;
	} else {
	   // 这里获取了四个参数，ReadTimeout，ConnectTimeout，MaxAutoRetries， MaxAutoRetriesNextServer
		int ribbonReadTimeout = getTimeout(config, commandKey, "ReadTimeout",
			IClientConfigKey.Keys.ReadTimeout, RibbonClientConfiguration.DEFAULT_READ_TIMEOUT);
		int ribbonConnectTimeout = getTimeout(config, commandKey, "ConnectTimeout",
			IClientConfigKey.Keys.ConnectTimeout, RibbonClientConfiguration.DEFAULT_CONNECT_TIMEOUT);
		int maxAutoRetries = getTimeout(config, commandKey, "MaxAutoRetries",
			IClientConfigKey.Keys.MaxAutoRetries, DefaultClientConfigImpl.DEFAULT_MAX_AUTO_RETRIES);
		int maxAutoRetriesNextServer = getTimeout(config, commandKey, "MaxAutoRetriesNextServer",
			IClientConfigKey.Keys.MaxAutoRetriesNextServer, DefaultClientConfigImpl.DEFAULT_MAX_AUTO_RETRIES_NEXT_SERVER);
		// 本来ribbonTimeout的计较要领在这里，以上文的配置为例
		// ribbonTimeout = (50000 + 50000) * (0 + 1) * (1 + 1) = 200000
		ribbonTimeout = (ribbonReadTimeout + ribbonConnectTimeout) * (maxAutoRetries + 1) * (maxAutoRetriesNextServer + 1);
	}
	return ribbonTimeout;
}

可以看到ribbonTimeout是一个总时间，所以从逻辑上来讲，作者但愿hystrixTimeout要大于ribbonTimeout，不然hystrix熔断了今后，ribbon的重试就都没有意义了。

ribbon单处事配置

到这里最前面的疑问已经解开了，可是hytrix可以分处事配置timeout，ribbon可不行以? 源码走起，昆山软件公司，这里看的文件是DefaultClientConfigImpl.java

// 这是获取设置的进口要领，假如是null，那么用默认值
// 所有ribbon的默认值的都在该类中配置了，可以本身看一下
public <T> T get(IClientConfigKey<T> key, T defaultValue) {
    T value = get(key);
    if (value == null) {
        value = defaultValue;
    }
    return value;
}
// 这是焦点要领   
protected Object getProperty(String key) {
    if (enableDynamicProperties) {
        String dynamicValue = null;
        DynamicStringProperty dynamicProperty = dynamicProperties.get(key);
        // dynamicProperties其实是一个缓存，首次会见foo处事的时候会加载
        if (dynamicProperty != null) {
            dynamicValue = dynamicProperty.get();
        }
        // 假如缓存没有，昆山软件开发，那么就再获取一次，留意这里的getConfigKey(key)是生成key的要领
        if (dynamicValue == null) {
            dynamicValue = DynamicProperty.getInstance(getConfigKey(key)).getString();
            // 假如照旧没有取默认值，getDefaultPropName(key)生成key的要领
            if (dynamicValue == null) {
                dynamicValue = DynamicProperty.getInstance(getDefaultPropName(key)).getString();
            }
        }
        if (dynamicValue != null) {
            return dynamicValue;
        }
    }
    return properties.get(key);
}

以我们的处事为例：

getConfigKey(key) returns foo.ribbon.ReadTimeout
getDefaultPropName(key) returns ribbon.ReadTimeout

一目了然，{serviceName}.ribbon.{propertyName}就可以了。

小结