Avoids listing the sorted logs dir multiple times during log recovery.#4874
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keith-turner merged 1 commit intoSep 13, 2024
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The log recovery code would list the sorted walog files multiple times during recovery. These changes modify the code to only list the files once. Also the listing is cached for a short period of time to improve the case of multiple tablet referencing the same walogs. This along with apache#4873 should result in much less traffic to the namenode when an entire accumulo cluster shutsdown and needs to recover.
dlmarion
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Sep 11, 2024
amcdonaldccri
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May 26, 2026
… log recovery. (apache#4874) The log recovery code would list the sorted walog files multiple times during recovery. These changes modify the code to only list the files once. Also the listing is cached for a short period of time to improve the case of multiple tablet referencing the same walogs. This along with apache#4873 should result in much less traffic to the namenode when an entire accumulo cluster shutsdown and needs to recover. {"fundingSource": "41201", "team": "FED.ICGSA.OPS.MOE", "fshGit": "dummy-lo", "fshDocker": "sha256:20cf0045"}
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The log recovery code would list the sorted walog files 3 to 4 times during recovery. These changes modify the code to only list the files once. Also the listing is cached for a short period of time to improve the case of multiple tablet referencing the same walogs. This along with #4873 should result in much less traffic to the namenode when an entire accumulo cluster shutsdown and needs to recover.
Noticed this while working on #4873. While working on that was generally trying to understand where the tsever was spending time when loading a tablet w/ walogs. Noticed these directory listing showing up a little bit in timing logging I added. Just a few milliseconds, but it seemed unnecessary to repeatedly list the same dir over and over. Suspect the impact is worse at scale.