(node:19360) DeprecationWarning: collection.ensureIndex is deprecated. Use createIndexes instead. (Use `node --trace-deprecation ...` to show where the warning was created) code example
Example: (node:3168) DeprecationWarning: collection.ensureIndex is deprecated. Use createIndexes instead. (Use `node --trace-deprecation ...` to show where the warning was created)
mongoose.set('useCreateIndex', true);