[SERVER-62484] Force deterministic splits points in balancer_defragmentation_merge_chunks.js Created: 10/Jan/22  Updated: 29/Oct/23  Resolved: 12/Jan/22

Status: Closed
Project: Core Server
Component/s: None
Affects Version/s: 5.3.0, 5.2.0
Fix Version/s: 5.3.0

Type: Bug Priority: Major - P3
Reporter: Tommaso Tocci Assignee: Allison Easton
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Depends
Backwards Compatibility: Fully Compatible
Operating System: ALL
Sprint: Sharding EMEA 2022-01-24
Participants:
Linked BF Score: 134

 Description   

In balancer_defragmentation_merge_chunks.js we rely on an unordered bulk insert plus the action of the chunk splitter to create the initial chunks for the test collections.

Unfortunately in case of write operation burst (such as bulk insert) the chunk splitter is not guarantee to split all the chunks correctly. In fact if a write operation arrives while the auto splitter is still performing a split operation triggered by a previous write, the latter will be ignored by the auto splitter.

One possible solution would be to not use bulk insert to populate the collection and instead issue several standalone insert operation in a loop and waitForOngoingChunkSplits between each iteration so to guarantee a deterministic number of final chunks (auto split actions).



 Comments   
Comment by Githook User [ 12/Jan/22 ]

Author:

{'name': 'Allison Easton', 'email': 'allison.easton@mongodb.com', 'username': 'allisoneaston'}

Message: SERVER-62484 Force deterministic splits points in balancer_defragmentation_merge_chunks.js
Branch: master
https://github.com/mongodb/mongo/commit/a11e822c1e05be2fa06d86a107ce151c55b16740

Generated at Thu Feb 08 05:55:15 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.