Understanding Azure IoT Edge OPCPublisher Diagnostic Information

I would like to understand the below diagnostic information. Can someone shed some lights? Especially the Ingress DataChanges (from OPC) & Ingress ValueChanges (from OPC)

[05:43:44 INF Microsoft.Azure.IIoT.OpcUa.Edge.Publisher.Engine.DataFlowProcessingEngine]
  DIAGNOSTICS INFORMATION for          : opc.tcp://<REDACTED>
  # Ingestion duration                 :    00:00:23:57 (dd:hh:mm:ss)
  # Ingress DataChanges (from OPC)     :              2 (0/s)
  # Ingress ValueChanges (from OPC)    :            154 (0.11/s)
  # Ingress BatchBlock buffer size     :              0
  # Encoding Block input/output size   :              0 | 0
  # Encoder Notifications processed    :            154
  # Encoder Notifications dropped      :              0
  # Encoder IoT Messages processed     :              1
  # Encoder avg Notifications/Message  :            154
  # Encoder avg IoT Message body size  :         50,551 (19%)
  # Encoder avg IoT Chunk (4 KB) usage :           12.3
  # Estimated IoT Chunks (4 KB) per day:            781
  # Outgress Batch Block buffer size   :              0
  # Outgress input buffer count        :              0
  # Outgress input buffer dropped      :              0
  # Outgress IoT message count         :              1 (0/s)
  # Connection retries                 :              0

Looks like the docs are here: Industrial-IoT/docs/opc-publisher/observability.md at main · Azure/Industrial-IoT · GitHub