I apologize for stopping the server for about 50 minutes in total for 2 days.
Probably there is a cause in Node.js 13.10 and newrelic npm 6.1.0. If these two were updated at the same time, the failure occurred three times in two days.
It is speculated that there is a relationship between newrelic getting mongodb metrics and increasing the number of read requests to mongodb.
Failures do not occur in the local development environment, but only in a production environment with many requests.
Reverted Node.js and newrelic npm versions.
Since then, no failure has occurred.