SERVER-128190 implemented a number of feature usage counters in MongoD. The objective of this ticket is to implement the metrics in MongoS:

• metrics.changeStreams.option.showExpandedEvents (counter)
• metrics.changeStreams.option.showMigrationEvents (counter)
• metrics.changeStreams.option.showSystemEvents (counter)
• metrics.changeStreams.option.showRawUpdateDescription (counter)
• metrics.changeStreams.option.ignoreRemovedShards (counter)
• metrics.changeStreams.option.matchCollectionUUIDForUpdateLookup (counter)
• metrics.changeStreams.option.startAfter (counter)
• metrics.changeStreams.option.resumeAfter (counter)
• metrics.changeStreams.option.startAtOperationTime (counter)
• metrics.changeStreams.option.fullDocument.required (counter)
• metrics.changeStreams.option.fullDocument.updateLookup (counter)
• metrics.changeStreams.option.fullDocument.whenAvailable (counter)
• metrics.changeStreams.option.fullDocumentBeforeChange.required (counter)
• metrics.changeStreams.option.fullDocumentBeforeChange.whenAvailable (counter)
• metrics.changeStreams.scope.cluster (counter)
• metrics.changeStreams.scope.db (counter)
• metrics.changeStreams.scope.collection (counter)

The first metric in this list existed before, but with a different name (metrics.changeStreams.showExpandedEvents), so this PR will rename the metric for consistency with the other metrics.

The metrics.changeStreams.option.showMigrationEvents metric will always be 0 on mongos, because the showMigrationEvents change stream flag is currently not supported on mongos.

References:

• Design doc section: https://docs.google.com/document/d/15JOvtmJd701ZDsskqeiw_5_WdD5m4E8NnSz9qPqAf1g/edit?tab=t.0