exp

Type Members

1. trait AbstractDarkTrafficFilter extends AnyRef

   

2. class BackupRequestFilter[Req, Rep] extends SimpleFilter[Req, Rep]

   

   Issue a backup request after a threshold time has elapsed, useful for curtailing tail latencies in distributed systems.

   Issue a backup request after a threshold time has elapsed, useful for curtailing tail latencies in distributed systems. See [1] for details.

   Several stats are exported through the given stats receiver exposing the filter's operating behavior:

   • counter timeouts indicates the number of original requests that timed out and subsequently caused a backup request to be issued;
   • counter won indicates the number of original requests that won, including those that didn't actually race with a backup;
   • counter lost indicates the number of original requests that lost a race with their corresponding backup request, and finally
   • gauge cutoff_ms indicates the current backup request cutoff value in milliseconds.

   [1]: Dean, J. and Barroso, L.A. (2013), The Tail at Scale, Communications of the ACM, Vol. 56 No. 2, Pages 74-80, http://cacm.acm.org/magazines/2013/2/160173-the-tail-at-scale/fulltext

   Note

   A filter alone cannot guarantee that a request is dispatched onto a different endpoint from the original. Eventually, this should be implemented as a sort of queueing policy.

   ,

   Care must be taken to ensure that application of this filter preserves semantics since a request may be issued twice (ie. they are idempotent).

3. class DarkTrafficFilter[Req, Rep] extends SimpleFilter[Req, Rep] with AbstractDarkTrafficFilter

   

   Forwards dark traffic to the given service when the given function returns true for a request.

4. abstract class ForwardingWarmUpFilter[Req, Rep] extends SimpleFilter[Req, Rep]

   

   A filter that forwards thrift requests to a specified service.

   A filter that forwards thrift requests to a specified service. It enables a smooth start of processing the requests by slowly increasing the percentage of requests that are being processed and lowering the amount of requests that are being forwarded.

5. class ThriftForwardingWarmUpFilter extends ForwardingWarmUpFilter[Array[Byte], Array[Byte]]