The Hystrix timeout of 2000ms for the command xxx is set lower than the combination of the Ribbon read and connect timeout, 4000ms.

该警告是在org.springframework.cloud.netflix.zuul.filters.route.support.AbstractRibbonCommand类的getHystrixTimeout方法中输出的，意思是断路器（Hystrix）设置的超时时间要比Ribbon设置的超时时间短。

hystrix超时设置：

hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds = 6000  # 默认超时时间
hystrix.command.xxx.execution.isolation.thread.timeoutInMilliseconds = 6000      # 具体应用的超时时间

ribbon超时时间计算：ribbonTimeout = (ribbonReadTimeout + ribbonConnectTimeout) * (maxAutoRetries + 1) * (maxAutoRetriesNextServer + 1)

ribbon全局设置，超时时间：(2000+1000)*(0+1)*(1+1)=6000：

ribbon.ReadTimeout = 2000            # 访问超时，单位毫秒，默认1000
ribbon.ConnectTimeout = 1000         # 连接超时，单位毫秒，默认1000
ribbon.MaxAutoRetries = 0            # 最大重试次数，默认0
ribbon.MaxAutoRetriesNextServer = 1  # 最大重试服务个数，默认1

ribbon针对具体服务设置，超时时间：(3000+1000)*(0+1)*(0+1)=4000：

zk-provider.ribbon.ReadTimeout = 3000
zk-provider.ribbon.ConnectTimeout = 1000
zk-provider.ribbon.MaxAutoRetries = 0
zk-provider.ribbon.MaxAutoRetriesNextServer = 0