MongoServerError: Resulting document after update is larger than 16777216

sivaprakash ramasamy

Im getting this following error in nodebb
nodebb: 1.19.1
mongodb: 4.4.8

(node:92) UnhandledPromiseRejectionWarning: MongoServerError: Resulting document after update is larger than 16777216
(node:92) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag --unhandled-rejections=strict (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 98784)
SB OIDC Token: Error while creating new user token Resulting document after update is larger than 16777216
SB OIDC Token: Error While checkig the tokens MongoServerError: Resulting document after update is larger than 16777216

Is there any solution for this issue ?

<baris>

This happens if a document has too much data, mongodb has a limit of 16mb per document. You can run something like below to find which document is the largest.

// biggest object
var max = 0;
var key = '';
db.objects.find().forEach(function(obj) {
    var curr = Object.bsonsize(obj);
    if(max < curr) {
        max = curr;
        key = obj._key;
    }
})
print(key);
print(max);

//execute with:
//mongo localhost:27017/<db_name> doc_size.js

sivaprakash ramasamy

@baris Do we have any option to increase the limit? Or is there any tool/plugin to migrate from mongodb to Redis

<baris>

@sivaprakash-ramasamy as far as I know there is no easy way to increase that limit in MongoDB.

What is the key that is storing 16mb? Can you change it to use a sorted set instead?