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  1. MongoDB Database Tools
  2. TOOLS-2377

Investigate troublesome tarball archive

    • Type: Icon: Task Task
    • Resolution: Gone away
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: mongorestore
    • Labels:

      HELP-11142 reported a tarball that would cause mongorestore to hang. We've been provided with the tarball via confidential means. This is a tracking ticket for that work.

      From that ticket, my thoughts on analyses:

      My off-the-cuff thoughts on analysis if we had the tarball:

      • Verify restoring (to a local DB) hangs with 4.2 tools and that it works with 4.0 tools
      • Repeat, but compile 4.2 tools with the same Go version as 4.0 to rule out Go scheduler or library changes/bugs
      • Repeat, but compile with the race detector turned on
      • Repeat, but with maximum debug output and/or added diagnostics to pinpoint differences between 4.0 and 4.2
      • Based on the information above, attempt to construct a minimal (synthetic) reproduction
        If necessary/indicated, write custom tools to inspect the archive format framing for correctness
      • If necessary/indicated, inspect archive file bytes around the hang point to identify BSON documents with possible corruption

      So I think looking at actual customer data in a human-readable way is a last resort – most of the work can treat the archive as a black box – and we could certainly discuss it with them before proceeding to that step.

      We are required to notify the customer before the final bullet point.

            david.golden@mongodb.com David Golden
            david.golden@mongodb.com David Golden
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