Replace AlwaysSample with ProbabilitySampler in router (#1348)

charts/README.md

@@ -70,6 +70,7 @@ Parameter | Description | Default
 `router.svcAddressUpdateTimeout` | The length of update lock expiry time for router to get a service URL returns from executor | `30`
 `router.svcAnnotations` | Annotations for router service | None
 `router.useEncodedPath` | For router to match encoded path. If true, "/foo%2Fbar" will match the path "/{var}"; Otherwise, it will match the path "/foo/bar". | `false`
+`router.traceSamplingRate` | Uniformly sample traces with the given probabilistic sampling rate | `0.5`
 `router.roundTrip.disableKeepAlive` | Disable transport keep-alive for fast switching function version | `true`
 `router.roundTrip.keepAliveTime` | The keep-alive period for an active network connection to function pod | `30s`
 `router.roundTrip.timeout` | HTTP transport request timeout | `50ms`

charts/fission-all/templates/router.yaml

@@ -54,7 +54,7 @@ spec:
           - name: ROUTER_SVC_ADDRESS_UPDATE_TIMEOUT
             value: {{ .Values.router.svcAddressUpdateTimeout | default "30s" | quote }}
           - name: TRACING_SAMPLING_RATE
-            value: {{ .Values.traceSamplingRate | default "0.5" | quote }}
+            value: {{ .Values.router.traceSamplingRate | default "0.5" | quote }}
           - name: USE_ENCODED_PATH
             value: {{ .Values.router.useEncodedPath | default false | quote }}
           - name: DEBUG_ENV

charts/fission-all/values.yaml

@@ -98,6 +98,9 @@ router:
     ## Max retries times of a failed request
     maxRetries: 10
 
+  ## Sample with a rate per time window (traces/second)
+  traceSamplingRate: 0.5
+
 ## Message queue trigger config
 ### NATS Streaming, enabled by default
 nats:

charts/fission-core/templates/router.yaml

@@ -54,7 +54,7 @@ spec:
           - name: ROUTER_SVC_ADDRESS_UPDATE_TIMEOUT
             value: {{ .Values.router.svcAddressUpdateTimeout | default "30s" | quote }}
           - name: TRACING_SAMPLING_RATE
-            value: {{ .Values.traceSamplingRate | default "0.5" | quote }}
+            value: {{ .Values.router.traceSamplingRate | default "0.5" | quote }}
           - name: USE_ENCODED_PATH
             value: {{ .Values.router.useEncodedPath | default false | quote }}
           - name: DEBUG_ENV

charts/fission-core/values.yaml

@@ -85,6 +85,9 @@ router:
     ## Max retries times of a failed request
     maxRetries: 10
 
+  ## Sample with a rate per time window (traces/second)
+  traceSamplingRate: 0.5
+
 ## Persist data to a persistent volume.
 persistence:
   ## If true, fission will create/use a Persistent Volume Claim