Need help diagnosing delayed writes to DB via Web API

influxdb
#1

Here’s the problem: The app is writing data to influxdb using the Web API. The volume of writes is fairly low, and the individual writes are small.

Most of the time the data will be inserted right away. Sometimes it takes about 16 minutes to appear in the table. The delay is always about this long when it occurs.

Influxdb is called using the blocking API from C++ on Ubuntu:
// save start time
// call blocking write API
// save end time
// end - start time is sometimes 16 minutes

The version of influxdb is 1.4 (upgrading to 1.7 soon).

Why would this be happening? I don’t think it’s compaction. There are no errors in the journalctl output.

What can be done to get more information about what is happening?

Thanks for any help.