records-lag-max

[Chen, Mason]

Hi all,

I am having some trouble with the lag metric from the kafka connector. The 
gauge value is always reported as NaN although I’m producing events first and 
then starting the flink job. Anyone know how to fix this?

```
# TYPE flink_taskmanager_job_task_operator_records_lag_max gauge
flink_taskmanager_job_task_operator_records_lag_max{ … } NaN
```

Thanks,
Mason