Operational Defect Database

BugZero found this defect 2410 days ago.

MongoDB | 406100

[SERVER-30232] delete command on mongos can return a negative count of deleted documents

Last update date:

12/6/2022

Affected products:

MongoDB Server

Affected releases:

3.2.10

Fixed releases:

No fixed releases provided.

Description:

Info

When a very large number of documents matches the query the count of deleted documents can overflow and become negative. I have reproduced this with 3.2.10. It works correctly in 3.4.6. This ticket might be a duplicate, but I couldn't find a ticket for this.

Top User Comments

charlie.swanson commented on Fri, 21 Jul 2017 16:08:06 +0000: I'm actually going to re-open this. While attempting to find which version this was fixed in, I realized there are actually many types involved in tracking how many deletes occurred on master, including: On mongod: local variable n in serializeReply, which uses a 'long long'. SingleWriteResult (generated by the IDL file), which uses a 'long', which it looks like IDL translates to an int64_t. The information on the SingleWriteResult looks to be filled out by requesting the number of deleted things from the DeleteStage, which does so by consulting it's DeleteStats, which uses a size_t On mongos: BatchWriteOp, which uses a 'int' BatchCommandResponse, which uses a 'long long' So it looks like all the types on mongod are ok (though the size_t should probably be replaced with a uint64_t, just to be sure). However, this is probably still a problem on mongos, and may still be a problem for update (or insert?). rstam if you're concerned with just a single mongod, it looks like this was likely fixed by SERVER-23128, which deleted the offending WriteOpStats which was storing an int. rstam commented on Fri, 21 Jul 2017 14:38:44 +0000: It would be helpful to users to know exactly which version this was fixed in. ian@10gen.com commented on Fri, 21 Jul 2017 14:35:33 +0000: Since this is already fixed in 3.4 and is simply a reporting error, we have no plans to fix this in 3.2.

Additional Resources / Links

Share:

BugZero Risk Score

Coming soon

Status

Backlog

Have you been affected by this bug?

cost-cta-background

Do you know how much operational outages are costing you?

Understand the cost to your business and how BugZero can help you reduce those costs.

Discussion

Login to read and write comments.

Have you ever...

had your data corrupted from a

VMware

bug?

Search:

...