why oplog.timestamp is null?

when I execute mongo-connector 2.4 sync to elasticsearch2.3.4 data sync correctly ,no errors,but oplog.timestamp file has nothing. does not it update timestamp like [“rs0”, 6339713900350538292] ? how and when mongo-connector will update oplog.timestamp? when I shutdown mongo-connector,and want to continue syn,I will wait too long ,data do not sync into elasticsearch . thanks,urgent!

I run mongo-connector like “mongo-connector -c config.json” and my config.json like here:

{
  "mainAddress": "*.*.*.*:27017",
  "oplogFile": "/data/opt/mongo-connector/oplog.timestamp",
  "verbosity": 1,
  "logging": {
    "type": "file",
    "filename": "/data/opt/mongo-connector/mongo-connector.log",
    "__rotationWhen": "D",
    "__rotationInterval": 1,
    "__rotationBackups": 10
  },
  "fields": ["_id",,"label","pinyin","begin_time","end_time"],
  "namespaces": {
    "include": ["aa.a", "bb.b"],
    "mapping": {
      "aa.a": "aa.a",
      "bb.b": "bb.b"
    }
  },
  "docManagers": [
    {
      "docManager": "elastic2_doc_manager",
      "targetURL": "*.*.*.*:9200",
      "bulkSize": 4000,
      "autoCommitInterval": null,
      "args": {
        "clientOptions": {"timeout": 300}
      }
    }
  ]
}

Edit: formatted json

[ShaneHarvey]

We should add a --version flag in the future but for now you can run:

$ pip freeze
elastic2-doc-manager==0.2.0
elasticsearch==2.4.0
mongo-connector==2.4.1
pymongo==3.3.0
pysolr==3.5.0
requests==2.11.1
urllib3==1.18

[ShaneHarvey]

Are you using mongo-connector v2.4 or v2.4.1?

The connector should update the timestamp to the latest replicated oplog entry every second. If the checkpoint is never set the cause may be different between versions. Can you post the log file or re-run with a higher logging "verbosity": 3?