hystrix应用介绍(四)
前几章已经讲了hystrix的应用场景,以及如何使用,本章我们针对如何进行hystrix参数配置做一些分析
//异步的执行 @HystrixCommand(groupKey = "testKey", commandKey = "testCommon", threadPoolKey = "getLiveVideoCoreThread", fallbackMethod = "getUserNameError", commandProperties = { @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "500"),//指定多久超时,单位毫秒。超时进fallback @HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "10"),//判断熔断的最少请求数,默认是10;只有在一个统计窗口内处理的请求数量达到这个阈值,才会进行熔断与否的判断 @HystrixProperty(name = "circuitBreaker.errorThresholdPercentage", value = "10"),//判断熔断的阈值,默认值50,表示在一个统计窗口内有10%的请求处理失败,会触发熔断 @HystrixProperty(name = "circuitBreaker.sleepWindowInMilliseconds", value = "3000"),//熔断多少秒后去尝试请求 }, threadPoolProperties = { @HystrixProperty(name = "coreSize", value = "20"), @HystrixProperty(name = "maxQueueSize", value = "50"), @HystrixProperty(name = "keepAliveTimeMinutes", value = "1"), @HystrixProperty(name = "queueSizeRejectionThreshold", value = "15"), @HystrixProperty(name = "metrics.rollingStats.numBuckets", value = "10"), @HystrixProperty(name = "metrics.rollingStats.timeInMilliseconds", value = "1000")}) public Future<String> getUserName(final Long id, String name) { return new AsyncResult<String>() { @Override public String invoke() { int i = 1/0;//此处抛异常,测试服务降级 return "你好:" + id; } }; }
fallbackMethod : 触发熔断器时执行的方法
GroupKey:该命令属于哪一个组,可以帮助我们更好的组织命令
CommandKey:该命令的名称
threadPoolKey:该命令所属线程池的名称,同样配置的命令会共享同一线程池,若不配置,会默认使用GroupKey作为线程池名称
commandProperties 配置解析
execution.isolation.thread.timeoutInMilliseconds : 指定多久超时,单位毫秒。超时进fallback
threadPoolProperties 配置解析
coreSize:配置核心线程池大小和线程池最大大小
maxQueueSize : 配置线程池队列最大大小