MongoDB CursorNotFound Error on collection.find() for a few hundred small records

Question

I\'m running on Mongo 3.6.6 (on a small Mongo Atlas cluster, not sharded) using the native Node JS driver (v. 3.0.10)

My code looks like this:

const          


        

Answer 1

You can try these 3 things:

---

a) Set the cursor to false

db.collection.find().noCursorTimeout();

You must close the cursor at some point with cursor.close();

---

b) Or reduce the batch size

db.inventory.find().batchSize(10);

---

c) Retry when the cursor expires:

let processed = 0;
let updated = 0;

while(true) {
    const cursor = db.snapshots.find().sort({ _id: 1 }).skip(processed);

    try {
        while (cursor.hasNext()) {
            const doc = cursor.next();

            ++processed;

            if (doc.stream && doc.roundedDate && !doc.sid) {
                db.snapshots.update({
                    _id: doc._id
                }, { $set: {
                    sid: `${ doc.stream.valueOf() }-${ doc.roundedDate }`
                }});

                ++updated;
            } 
        }

        break; // Done processing all, exit outer loop
    } catch (err) {
        if (err.code !== 43) {
            // Something else than a timeout went wrong. Abort loop.

            throw err;
        }
    }
}