[SERVER-77700] Replace MurmurHash3 with absl::Hash if possible in HashBlock::Hash Created: 01/Jun/23  Updated: 29/Oct/23  Resolved: 07/Jul/23

Status: Closed
Project: Core Server
Component/s: None
Affects Version/s: None
Fix Version/s: 7.1.0-rc0

Type: Task Priority: Major - P3
Reporter: Dan Larkin-York Assignee: Mark Benvenuto
Resolution: Fixed Votes: 0
Labels: perf-server-security
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Problem/Incident
Assigned Teams:
Server Security
Backwards Compatibility: Fully Compatible
Sprint: Security 2023-06-26, Security 2023-07-10
Participants:
Linked BF Score: 175

 Description   

MurmurHash3 is a pretty old hash function that's slow and produces low-quality hashes compared to modern alternatives like absl::Hash (CityHash). We want to replace any uses of MurmurHash3 which are for in-memory use only, as we expect this to yield quick perf wins. Hash values that are persisted to disk across restarts or sent across the network between servers are likely unsafe to change, and should be annotated with a clear explanation for why the usage requires a stable hash computation.



 Comments   
Comment by Githook User [ 06/Jul/23 ]

Author:

{'name': 'Mark Benvenuto', 'email': 'mark.benvenuto@mongodb.com', 'username': 'markbenvenuto'}

Message: SERVER-77700 Replace MurmurHash3 with absl::Hash if possible in HashBlock::Hash
Branch: master
https://github.com/mongodb/mongo/commit/0856acc954f99183854cc151d1fb07b61c4ef7bf

Comment by Githook User [ 03/Jul/23 ]

Author:

{'name': 'liubov.molchanova', 'email': 'liubov.molchanova@mongodb.com', 'username': 'liubov-molchanova'}

Message: Revert "SERVER-77700 Replace MurmurHash3 with absl::Hash if possible in HashBlock::Hash"

This reverts commit 0685743d3a2b077a54a4d06f23a9d807ba3efe5c.
Branch: EVG-17874-taskgen-test
https://github.com/mongodb/mongo/commit/9b0bd760d2704daeb1c940be5cfe5801c5e00238

Comment by Githook User [ 03/Jul/23 ]

Author:

{'name': 'Mark Benvenuto', 'email': 'mark.benvenuto@mongodb.com', 'username': 'markbenvenuto'}

Message: SERVER-77700 Replace MurmurHash3 with absl::Hash if possible in HashBlock::Hash
Branch: EVG-17874-taskgen-test
https://github.com/mongodb/mongo/commit/0685743d3a2b077a54a4d06f23a9d807ba3efe5c

Comment by Githook User [ 30/Jun/23 ]

Author:

{'name': 'liubov.molchanova', 'email': 'liubov.molchanova@mongodb.com', 'username': 'liubov-molchanova'}

Message: Revert "SERVER-77700 Replace MurmurHash3 with absl::Hash if possible in HashBlock::Hash"

This reverts commit 0685743d3a2b077a54a4d06f23a9d807ba3efe5c.
Branch: master
https://github.com/mongodb/mongo/commit/9b0bd760d2704daeb1c940be5cfe5801c5e00238

Comment by Githook User [ 29/Jun/23 ]

Author:

{'name': 'Mark Benvenuto', 'email': 'mark.benvenuto@mongodb.com', 'username': 'markbenvenuto'}

Message: SERVER-77700 Replace MurmurHash3 with absl::Hash if possible in HashBlock::Hash
Branch: master
https://github.com/mongodb/mongo/commit/0685743d3a2b077a54a4d06f23a9d807ba3efe5c

Generated at Thu Feb 08 06:36:20 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.