Internal server error on set followed by unset

mstniy commented 2 years ago

New Issue Checklist

[x] I am not disclosing a vulnerability.
[x] I am not just asking a question.
[x] I have searched through existing issues.
[x] I can reproduce the issue with the latest version of Parse Server.

Issue Description

Setting a subdocument entirely, followed by an unset of a nested field causes an internal server error while the object is being saved, if the object existed beforehand.

Steps to reproduce

const myObj = new Parse.Object('MyClass');
await myObj.save(null, {useMasterKey: true});
myObj.set('data', {a: 5});
myObj.unset('data.a');
await myObj.save(null, {useMasterKey: true});
console.log('a');

Actual Outcome

error: Uncaught internal server error. Updating the path 'data.a' would create a conflict at 'data' {"code":40,"codeName":"ConflictingUpdateOperators","ok":0,"stack":"MongoServerError: Updating the path 'data.a' would create a conflict at 'data'\n    at Connection.onMessage (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/connection.js:202:30)\n    at MessageStream.<anonymous> (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/connection.js:62:60)\n    at MessageStream.emit (events.js:400:28)\n    at processIncomingData (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/message_stream.js:108:16)\n    at MessageStream._write (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/message_stream.js:28:9)\n    at writeOrBuffer (internal/streams/writable.js:358:12)\n    at MessageStream.Writable.write (internal/streams/writable.js:303:10)\n    at Socket.ondata (internal/streams/readable.js:731:22)\n    at Socket.emit (events.js:400:28)\n    at addChunk (internal/streams/readable.js:293:12)"}
MongoServerError: Updating the path 'data.a' would create a conflict at 'data'
    at Connection.onMessage (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/connection.js:202:30)
    at MessageStream.<anonymous> (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/connection.js:62:60)
    at MessageStream.emit (events.js:400:28)
    at processIncomingData (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/message_stream.js:108:16)
    at MessageStream._write (/home/kartal/Desktop/ocell/parse-server-example/node_modules/parse-server/node_modules/mongodb/lib/cmap/message_stream.js:28:9)
    at writeOrBuffer (internal/streams/writable.js:358:12)
    at MessageStream.Writable.write (internal/streams/writable.js:303:10)
    at Socket.ondata (internal/streams/readable.js:731:22)
    at Socket.emit (events.js:400:28)
    at addChunk (internal/streams/readable.js:293:12)

Expected Outcome

The object should be saved to the database with data = {}

Environment

Server

Parse Server version: 5.3.0
Operating system: ubuntu 20.04
Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): local

Database

System (MongoDB or Postgres): MongoDB
Database version: 5.0.13
Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): local

Client

SDK (iOS, Android, JavaScript, PHP, Unity, etc): parse dashboard
SDK version: 4.1.4

Logs

parse-github-assistant[bot] commented 1 year ago

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parse-github-assistant[bot] commented 2 years ago

Thanks for opening this issue!

🚀 You can help us to fix this issue faster by opening a pull request with a failing test. See our Contribution Guide for how to make a pull request, or read our New Contributor's Guide if this is your first time contributing.

mtrezza commented 2 years ago

Nice find! Do you want to open a PR? This may well be a Parse JS SDK issue rather than a Parse Server issue, if the SDK doesn't handle this set / unset properly. Did you look at what the SDK sends to the server?

mstniy commented 2 years ago

I have verified that the SDK sends a malformed request to the server, so this is an SDK issue.

mtrezza commented 2 years ago

Great, would you want to open a PR with a failing test?

mtrezza commented 1 year ago

@mstniy Do you have any more infos on this issue? Otherwise I'll transfer it to the Parse JS SDK.

mstniy commented 1 year ago

I am afraid not, @mtrezza . Feel free to transfer the issue. We ended up working around it.

mortenmo commented 6 months ago

Looking at this for a moment, not sure there isn't more related issues.

Trying to just add data.b (not unsetting) and trying to get it after removes locally the previous value. It doesn't merge the ops locally.

I didn't realize dot notation was even supported on set/get, but there seem to be a lot of issues with it.

harshbhar0629 commented 1 month ago

Steps to reproduce const myObj = new Parse.Object('MyClass'); await myObj.save(null, {useMasterKey: true}); myObj.set('data', {a: 5}); myObj.unset('data.a'); await myObj.save(null, {useMasterKey: true}); console.log('a');

Above code gives internal server error because of conflict.

MY Solution: The error you're encountering is due to conflicting update operations in MongoDB. Specifically, you're trying to unset a nested field (data.a) after modifying the object, which is causing MongoDB to throw the ConflictingUpdateOperators error because it doesn't allow multiple operations that affect the same path in a single update.

Here's how you can resolve it:

Solution 1: Use Separate Saves Instead of updating and unsetting in the same save operation, separate them into distinct saves to avoid conflicting update operators.

conflictingSol1

Explanation Initial Save: The object is first saved with no changes. Set and Save: The object’s data field is set with the value { a: 5 } and saved. Unset and Save: The nested field data.a is then unset and saved again in a separate operation.

@mtrezza Please review it once:)

mtrezza commented 1 month ago

Specifically, you're trying to unset a nested field (data.a) after modifying the object, which is causing MongoDB to throw the ConflictingUpdateOperators error because it doesn't allow multiple operations that affect the same path in a single update.

@harshbhar0629 Good analysis, I think we may have 2 issues here:

If the MongoDB driver returns an error, like ConflictingUpdateOperators, then the server should not have an internal error, but the error should be caught, logged with details, and a general Parse Error should be returned, without any specific internal error details for security reasons.
Given your code example above, there seems to be an issue in how we handle set-unset combinations to form the DB request.

Would you want to write a fix? You could start with a PR that contains the code example you posted above to demonstrate the issue.

harshbhar0629 commented 1 month ago

I will try to fix that issue Sir:)

mtrezza commented 1 month ago

@harshbhar0629 I didn't notice but we already have an open PR with https://github.com/parse-community/Parse-SDK-JS/pull/2117. Please see the discussion there and feel free to pick up from there, as the PR seems to have gone stale.

parse-community / Parse-SDK-JS