Hystrix Configuration EIP

The Hystrix Configuration EIP supports 31 options which are listed below:

Name Description Default Type

groupKey

Sets the group key to use. The default value is CamelHystrix.

CamelHystrix

String

threadPoolKey

Sets the thread pool key to use. Will by default use the same value as groupKey has been configured to use.

CamelHystrix

String

circuitBreakerEnabled

Whether to use a HystrixCircuitBreaker or not. If false no circuit-breaker logic will be used and all requests permitted. This is similar in effect to circuitBreakerForceClosed() except that continues tracking metrics and knowing whether it should be open/closed, this property results in not even instantiating a circuit-breaker.

true

Boolean

circuitBreakerError ThresholdPercentage

Error percentage threshold (as whole number such as 50) at which point the circuit breaker will trip open and reject requests. It will stay tripped for the duration defined in circuitBreakerSleepWindowInMilliseconds; The error percentage this is compared against comes from HystrixCommandMetrics.getHealthCounts().

50

Integer

circuitBreakerForceClosed

If true the HystrixCircuitBreaker#allowRequest() will always return true to allow requests regardless of the error percentage from HystrixCommandMetrics.getHealthCounts(). The circuitBreakerForceOpen() property takes precedence so if it set to true this property does nothing.

false

Boolean

circuitBreakerForceOpen

If true the HystrixCircuitBreaker.allowRequest() will always return false, causing the circuit to be open (tripped) and reject all requests. This property takes precedence over circuitBreakerForceClosed();

false

Boolean

circuitBreakerRequestVolume Threshold

Minimum number of requests in the metricsRollingStatisticalWindowInMilliseconds() that must exist before the HystrixCircuitBreaker will trip. If below this number the circuit will not trip regardless of error percentage.

20

Integer

circuitBreakerSleepWindow InMilliseconds

The time in milliseconds after a HystrixCircuitBreaker trips open that it should wait before trying requests again.

5000

Integer

executionIsolationSemaphore MaxConcurrentRequests

Number of concurrent requests permitted to HystrixCommand.run(). Requests beyond the concurrent limit will be rejected. Applicable only when executionIsolationStrategy == SEMAPHORE.

20

Integer

executionIsolationStrategy

What isolation strategy HystrixCommand.run() will be executed with. If THREAD then it will be executed on a separate thread and concurrent requests limited by the number of threads in the thread-pool. If SEMAPHORE then it will be executed on the calling thread and concurrent requests limited by the semaphore count.

THREAD

String

executionIsolationThread InterruptOnTimeout

Whether the execution thread should attempt an interrupt (using Future#cancel) when a thread times out. Applicable only when executionIsolationStrategy() == THREAD.

true

Boolean

executionTimeoutIn Milliseconds

Time in milliseconds at which point the command will timeout and halt execution. If executionIsolationThreadInterruptOnTimeout == true and the command is thread-isolated, the executing thread will be interrupted. If the command is semaphore-isolated and a HystrixObservableCommand, that command will get unsubscribed.

1000

Integer

executionTimeoutEnabled

Whether the timeout mechanism is enabled for this command

true

Boolean

fallbackIsolationSemaphore MaxConcurrentRequests

Number of concurrent requests permitted to HystrixCommand.getFallback(). Requests beyond the concurrent limit will fail-fast and not attempt retrieving a fallback.

10

Integer

fallbackEnabled

Whether HystrixCommand.getFallback() should be attempted when failure occurs.

true

Boolean

metricsHealthSnapshot IntervalInMilliseconds

Time in milliseconds to wait between allowing health snapshots to be taken that calculate success and error percentages and affect HystrixCircuitBreaker.isOpen() status. On high-volume circuits the continual calculation of error percentage can become CPU intensive thus this controls how often it is calculated.

500

Integer

metricsRollingPercentile BucketSize

Maximum number of values stored in each bucket of the rolling percentile. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.

10

Integer

metricsRollingPercentile Enabled

Whether percentile metrics should be captured using HystrixRollingPercentile inside HystrixCommandMetrics.

true

Boolean

metricsRollingPercentile WindowInMilliseconds

Duration of percentile rolling window in milliseconds. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.

10000

Integer

metricsRollingPercentile WindowBuckets

Number of buckets the rolling percentile window is broken into. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.

6

Integer

metricsRollingStatistical WindowInMilliseconds

This property sets the duration of the statistical rolling window, in milliseconds. This is how long metrics are kept for the thread pool. The window is divided into buckets and rolls by those increments.

10000

Integer

metricsRollingStatistical WindowBuckets

Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside HystrixCommandMetrics.

10

Integer

requestLogEnabled

Whether HystrixCommand execution and events should be logged to HystrixRequestLog.

true

Boolean

corePoolSize

Core thread-pool size that gets passed to java.util.concurrent.ThreadPoolExecutor#setCorePoolSize(int)

10

Integer

maximumSize

Maximum thread-pool size that gets passed to ThreadPoolExecutor#setMaximumPoolSize(int). This is the maximum amount of concurrency that can be supported without starting to reject HystrixCommands. Please note that this setting only takes effect if you also set allowMaximumSizeToDivergeFromCoreSize

10

Integer

keepAliveTime

Keep-alive time in minutes that gets passed to {link ThreadPoolExecutor#setKeepAliveTime(long, TimeUnit)}

1

Integer

maxQueueSize

Max queue size that gets passed to BlockingQueue in HystrixConcurrencyStrategy.getBlockingQueue(int) This should only affect the instantiation of a threadpool - it is not eliglible to change a queue size on the fly. For that, use queueSizeRejectionThreshold().

-1

Integer

queueSizeRejectionThreshold

Queue size rejection threshold is an artificial max size at which rejections will occur even if maxQueueSize has not been reached. This is done because the maxQueueSize of a BlockingQueue can not be dynamically changed and we want to support dynamically changing the queue size that affects rejections. This is used by HystrixCommand when queuing a thread for execution.

5

Integer

threadPoolRollingNumber StatisticalWindowIn Milliseconds

Duration of statistical rolling window in milliseconds. This is passed into HystrixRollingNumber inside each HystrixThreadPoolMetrics instance.

10000

Integer

threadPoolRollingNumber StatisticalWindowBuckets

Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside each HystrixThreadPoolMetrics instance.

10

Integer

allowMaximumSizeToDiverge FromCoreSize

Allows the configuration for maximumSize to take effect. That value can then be equal to, or higher, than coreSize

false

Boolean