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  1. WiredTiger
  2. WT-9096

Fix search near returning wrong key/value sometimes when key doesn't exist

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    • 8
    • Storage - Ra 2022-04-18
    • v6.0, v5.0, v4.4

    Description

      As part of implementing WT-8707, a bug was uncovered in develop. Note: checkpoint test was slightly modified to reproduce this bug.

      Test command: 

      ./test_checkpoint -t r -W 1 -r 1 -s 1 -x -n 100000 -k 100000 -C cache_size=10MB 

      The bug scenario is described below:

      • Keys in btree (sorted order)
        •  key: 52454
          • value: 9704
          • commit timestamp: 904
        • key:52471 
          • value: 1289
          • commit timestamp: 22
      • Performed a search near (read timestamp: 795)
        • Key Searched: 52459 (doesn't exist in btree)
        • Value returned 1289
        • However, the key returned was 52454.

      Note: Even though the test fails consistently, the scenario described above fails rarely, mostly the correct key is returned.

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            haribabu.kommi@mongodb.com Haribabu Kommi
            siddhartha.mahajan@mongodb.com Sid Mahajan
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              Created:
              Updated:
              Resolved: