Class CircuitBreakerFilter
- java.lang.Object
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- org.forgerock.openig.filter.circuitbreaker.CircuitBreakerFilter
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- All Implemented Interfaces:
Filter
public class CircuitBreakerFilter extends Object implements Filter
Filter implementing the Circuit Breaker pattern to avoid cascading failures.When a maxFailures number of errors is reached, the "circuit" will open up : the downstream handler will not be called anymore and requests will be forwarded to the openHandler.
After openDuration duration, the "circuit" will close again and let the requests go through the downstream handler again.
Note : Only
RuntimeException
are considered as failures.Configuration options:
{ "type": "CircuitBreakerFilter", "config": { "maxFailures": integer [REQUIRED - The maximum number of failures before opening the circuit] "openDuration": duration [REQUIRED - The duration that the circuit will remain open for, once opened] "slidingCounter": { "size": integer [REQUIRED - The number of last requests to consider. Must be greater than 'maxFailures'] } "openHandler": Handler reference [OPTIONAL - The handler that will handle requests while the circuit is open.. Defaults to a static RuntimeException. "executor": ScheduledExecutorService reference [OPTIONAL - The scheduler to use to schedule the re-closure of the circuit when opened. Defaults to the one present in the heap] } }
Example using a
SlidingCounterResultRecorder
: the circuit will open up for 1 minute, after 10 failures in the previous 100 requests using the ScheduledExecutorService already present in the heap.{ "type": "CircuitBreakerFilter", "config": { "maxFailures": 10, "openDuration": "1 minute", "slidingCounter": { "size": 100 } } }
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
CircuitBreakerFilter.Heaplet
The Heaplet used to create aCircuitBreakerFilter
heap object.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Promise<Response,NeverThrowsException>
filter(Context context, Request request, Handler next)
Filters the request and/or response of an exchange.
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Method Detail
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filter
public Promise<Response,NeverThrowsException> filter(Context context, Request request, Handler next)
Description copied from interface:Filter
Filters the request and/or response of an exchange. To pass the request to the next filter or handler in the chain, the filter callsnext.handle(context, request)
.This method may elect not to pass the request to the next filter or handler, and instead handle the request itself. It can achieve this by merely avoiding a call to
next.handle(context, request)
and creating its own response object. The filter is also at liberty to replace a response with another of its own by intercepting the response returned by the next handler.
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