Add drop reason aggregation enums to MoD config

Summary: Add drop reason aggregation enums to MoD config so that they can be easily fine-tuned in prod

Reviewed By: nivinl

Differential Revision: D66850344

fbshipit-source-id: 4b98944b2a1b46ff94f1f9d5f65b42160f942141

fboss/agent/switch_config.thrift

@@ -370,6 +370,21 @@ struct Mirror {
   5: optional i32 samplingRate;
 }
 
+/*
+ * Aggregation of mirror-on-drop reasons. The exact drop reasons corresponding to each
+ * enum is platform-specific and is converted in the platform-specific SaiTamManagers.
+ */
+enum MirrorOnDropReasonAggregation {
+  UNEXPECTED_REASON_DISCARDS = 0,
+
+  INGRESS_MISC_DISCARDS = 1,
+  INGRESS_PACKET_PROCESSING_DISCARDS = 2,
+  INGRESS_QUEUE_RESOLUTION_DISCARDS = 3,
+  INGRESS_SOURCE_CONGESTION_DISCARDS = 4, // e.g. VSQ
+  INGRESS_DESTINATION_CONGESTION_DISCARDS = 5, // e.g. VOQ
+  INGRESS_GLOBAL_CONGESTION_DISCARDS = 6,
+}
+
 struct MirrorOnDropReport {
   1: string name;
   /*
@@ -389,6 +404,8 @@ struct MirrorOnDropReport {
   8: byte dscp = 0;
   // At most one mirrored packet will be sent per port/PG/VOQ within an interval. Granularity is not configurable as of now.
   9: optional i32 agingIntervalUsecs;
+  // Mapping from drop ID / event ID to groups of reasons.
+  10: map<byte, list<MirrorOnDropReasonAggregation>> eventIdToDropReasons;
 }
 
 /**

fboss/agent/switch_state.thrift

@@ -331,6 +331,10 @@ struct MirrorOnDropReportFields {
   10: optional i32 agingIntervalUsecs;
   11: string switchMac; // Populated at runtime
   12: string firstInterfaceMac; // Populated at runtime
+  13: map<
+    byte,
+    list<switch_config.MirrorOnDropReasonAggregation>
+  > eventIdToDropReasons;
 }
 
 struct ControlPlaneFields {