动态修改hystrix配置项

Hystrix默认使用​​Archaius​​来实现的动态配置，下面是一个Command的实现：

Archaius 默认支持两种方式来加载本地的配置文件：

1. 默认情况下，Archaius默认会加载classpath下的config.properties文件
2. 在程序启动的时候，加如下的启动参数：-Darchaius.configurationSource.additionalUrls=file:///apps/myapp/application.properties

注：在代码中动态修改配置项的值，是无效的。

Hystrix支持的动态配置列表如下：

官网：​​https://github.com/Netflix/Hystrix/wiki/Configuration​​

​​Command Properties​​

1. ​​Execution​​

1. ​​execution.isolation.strategy​​
2. ​​execution.isolation.thread.timeoutInMilliseconds​​
3. ​​execution.timeout.enabled​​
4. ​​execution.isolation.thread.interruptOnTimeout​​
5. ​​execution.isolation.thread.interruptOnCancel​​
6. ​​execution.isolation.semaphore.maxConcurrentRequests​​

2. ​​Fallback​​

1. ​​fallback.isolation.semaphore.maxConcurrentRequests​​
2. ​​fallback.enabled​​

3. ​​Circuit Breaker​​

1. ​​circuitBreaker.enabled​​
2. ​​circuitBreaker.requestVolumeThreshold​​
3. ​​circuitBreaker.sleepWindowInMilliseconds​​
4. ​​circuitBreaker.errorThresholdPercentage​​
5. ​​circuitBreaker.forceOpen​​
6. ​​circuitBreaker.forceClosed​​

4. ​​Metrics​​

1. ​​metrics.rollingStats.timeInMilliseconds​​
2. ​​metrics.rollingStats.numBuckets​​
3. ​​metrics.rollingPercentile.enabled​​
4. ​​metrics.rollingPercentile.timeInMilliseconds​​
5. ​​metrics.rollingPercentile.numBuckets​​
6. ​​metrics.rollingPercentile.bucketSize​​
7. ​​metrics.healthSnapshot.intervalInMilliseconds​​

5. ​​Request Context​​

1. ​​requestCache.enabled​​
2. ​​requestLog.enabled​​

​​Collapser Properties​​

1. ​​maxRequestsInBatch​​
2. ​​timerDelayInMilliseconds​​
3. ​​requestCache.enabled​​

​​Thread Pool Properties​​

1. ​​coreSize​​
2. ​​maximumSize​​
3. ​​maxQueueSize​​
4. ​​queueSizeRejectionThreshold​​
5. ​​keepAliveTimeMinutes​​
6. ​​allowMaximumSizeToDivergeFromCoreSize​​
7. ​​metrics.rollingStats.timeInMilliseconds​​
8. ​​metrics.rollingStats.numBuckets​​