Influxdb timestamp is slow

The date time when I used the telegraf with -test command to output data is 1504143831000000000 (2017-08-31t01:51Z), while sending the data to Influxdb database, the timestamp is slow for about 30 minutes (2017-08-31T01:11:30Z), where is the problem?

When using the --test option the metrics are not sent to the outputs, only printed to the screen.

yes, I know thant using the --test option only printed to the screen ,But the latest time to send to Influxdb is always half an hour slower than the current system time

Have you checked that both systems have the correct system time?

System time is correct

The only thing I can think of that would cause this is if Telegraf was unable to send to InfluxDB for the 30 minutes. If this happened there would be plenty of error messages in Telegraf’s logfile, do you see anything in there?

influxdb system time is :

telegraf Collector System Time is

Telegraf’s logfile :

It looks like the machine you are trying to ping is down or you don’t have network connectivity. Is this expected?