MongoDB 4.2.7 Bug - Off-by-one overflow in block-modification bitmaps for incremental backup

26 June,2020 by Jack Vamvas

A bug on MongoDB 4.2.7 has been identified- and a fix is included in 4.2.8 .Certain conditions are required for the bug to appear - detailed below. Based on the supporting documentation for the MongoDB 4.2.7  bug to occur:

  • Must be running MongoDB 4.2.7.
  • Managed by Ops Manager 4.2.13+ or managed in Cloud Manager with MongoDB agent version v10.14.0+.
  • Incremental backups are enabled.
  • The DB server has  collection files greater than 2GB on disk.
  • These collections are modified anytime after backups are enabled.

If these conditions are met , there is a possibility that MongoDB will improperly overwrite memory.

Read here for greater detail supplied by MongoDB

To fix you will need to upgrade the Replica Set version from 4.2.7 to 4.2.8 . The upgrade does require a host restart - so ensure all checks are made regarding data recovery points and any existing users connected which which you can get using How to list MongoDB connections - client ip and port

 

 


Author: Jack Vamvas (http://www.dba-ninja.com)


Share:

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment on MongoDB 4.2.7 Bug - Off-by-one overflow in block-modification bitmaps for incremental backup


dba-ninja.com