anchor.diff:  |Attributes |Type |Description
   
   |[[log-miner-metrics-currentscn]]<<log-miner-metrics-currentscn, `+CurrentScn+`>>
  -|`long`
  +|`string`
   |The most recent SCN that has been processed.
   
   |[[log-miner-metrics-currentredologfilename]]<<log-miner-metrics-currentredologfilename, `+CurrentRedoLogFileName+`>>
  
positive.code:             "name": "server1",
              "ts_ms": 1520085154000,
              "txId": "6.28.807",
              "scn": 2122185,
              "commit_scn": 2122185,
              "snapshot": false
          },
          "op": "c",
  
negative.code:                         "field": "txId"
                      },
                      {
                          "type": "string",
                          "optional": true,
                          "field": "scn"
                      },
                      {
                          "type": "string",
                          "optional": true,
                          "field": "commit_scn"
                      },
  