[SERVER-49843] Stress test building a unique index with a large number of non-unique keys Created: 23/Jul/20  Updated: 29/Oct/23  Resolved: 30/Oct/20

Status: Closed
Project: Core Server
Component/s: None
Affects Version/s: None
Fix Version/s: 4.9.0

Type: Task Priority: Major - P3
Reporter: Gregory Noma Assignee: Brian DeLeonardis (Inactive)
Resolution: Fixed Votes: 0
Labels: newgrad
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Backwards Compatibility: Fully Compatible
Sprint: Execution Team 2020-11-02
Participants:

 Description   

For SERVER-48067, I measured performance by building a unique index on a standalone on a field that was identical in 2 million documents. One of the times I ran this build, it hit this invariant with a WriteConflict. The exception appears to have occurred sometime after inserting keys from the external sorted into the index, which was the last log message printed before the invariant was hit (with default log verbosity). Having a stress test here (probably either a standard jstest or an FSM jstest) will hopefully help reproduce this and identify where the WriteConflict escaped from. Note that I specified "a unique index with a large number of non-unique keys" in the title since that's the scenario I ran into this issue with, but it could be unrelated to this specific configuration.



 Comments   
Comment by Githook User [ 30/Oct/20 ]

Author:

{'name': 'Brian DeLeonardis', 'email': 'brian.deleonardis@mongodb.com', 'username': 'bdeleonardis1'}

Message: SERVER-49843 Stress test unique index builds
Branch: master
https://github.com/mongodb/mongo/commit/4fba6de9eb1dea5895845cc06bd206f7b0ea3cf3

Comment by Brian DeLeonardis (Inactive) [ 29/Oct/20 ]

Code review: https://mongodbcr.appspot.com/696960001/

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