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  1. Apache NiFi
  2. NIFI-8633

Content Repository can be improved to make fewer disks accesses on read

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 1.14.0
    • Component/s: Core Framework
    • Labels:
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      Description

      When FileSystemRepository.read(ContentClaim) or FileSystemRepository.read(ResourceClaim) is called, the repository determines the file path for the claim via getPath(claim, true); where the true indicates that we should verify that the file exists.

      This is done so that if we were to pass in a ContentClaim that does not exist, we throw a more meaningful ContentNotFoundException instead of just letting a FileNotFoundException fly.

      However, this call to Files.exists(Path) is fairly expensive, as it's a disk access. For a flow that uses a lot of smaller files, this can be extremely expensive.

      We can improve this by removing the call to Files.exists all together. Instead, just blindly create the FileInputStream in a try/catch block and catch FileNotFoundException, and then wrap that in a ContentNotFoundException. This results in the same API and the same contracts as before but avoids the overhead of additional disk accesses/seeks.

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              • Assignee:
                markap14 Mark Payne
                Reporter:
                markap14 Mark Payne
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