docs(changelog): document front50's new getTriggeredPipelines endpoin…

…t and how to configure orca to use it (#335)

content/en/docs/releases/next-release-preview/index.md

@@ -14,8 +14,14 @@ changelog.
 ### [doNotEval SpEL helper](https://spinnaker.io/changelogs/1.30.0-changelog/#donoteval-spel-helper)
 This feature is now enabled by default
 
+### Orca
+
+https://github.com/spinnaker/orca/pull/4448 adds a new configuration flag: `front50.useTriggeredByEndpoint` that defaults to false. When false, orca queries front50 for all pipelines each time a pipeline execution completes. When true, orca only queries for pipelines triggered when a specific pipeline completes which is potentially a very small subset of all pipelines.
+
 ### Front50
 
+https://github.com/spinnaker/front50/pull/1251 adds a new GET /pipelines/triggeredBy/{id:.+}/{status} endpoint.
+
 https://github.com/spinnaker/front50/pull/1249 adds three new configuration flags for [each object type under service-storage](https://github.com/spinnaker/front50/blob/568743732dcb47cc576a178795b6a992923f1d3c/front50-core/src/main/java/com/netflix/spinnaker/front50/config/StorageServiceConfigurationProperties.java#L8).
 
 * storage-service.*.cacheHealthCheckTimeoutSeconds: The cache is considered healthy if it's been refreshed in `cacheHealthCheckTimeoutSeconds` seconds. The default is 90.