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  1. Core Server
  2. SERVER-27395

$bucketAuto aggregation with $addToSet output accumulator crashes mongod

    • Type: Icon: Bug Bug
    • Resolution: Duplicate
    • Priority: Icon: Blocker - P1 Blocker - P1
    • None
    • Affects Version/s: 3.4.0
    • Component/s: Aggregation Framework
    • Labels:
      None
    • ALL
    • v3.4
    • Hide

      Scripts attached in the attached tar.gz file, including an already-crashed mongod dbpath (data/*) and log (mongod.log).

      Steps:
      1) Download 3.4.0 to /opt/mongodb-linux-x86_64-3.4.0 (or modify the scripts)
      2) "./prepare.sh" - starts mongod and inserts 1 x doc
      3) "./run.sh" - runs the aggregate query, crashes mongod

      Show
      Scripts attached in the attached tar.gz file, including an already-crashed mongod dbpath (data/*) and log (mongod.log). Steps: 1) Download 3.4.0 to /opt/mongodb-linux-x86_64-3.4.0 (or modify the scripts) 2) "./prepare.sh" - starts mongod and inserts 1 x doc 3) "./run.sh" - runs the aggregate query, crashes mongod
    • Query 2017-01-23

      When using $bucketAuto with an $addToSet accumulator within the 'output' document can crash mongod.

      An example query that can crash mongod:

      db.tweets.aggregate([
        { $bucketAuto: {
          groupBy: "$user.location",
          buckets: 1,
          output: {
            count: { $sum: 1 },
            location: { $addToSet: "$user.location" } 
          } 
        } }
      ])
      

      This query is probably silly/not-useful because I think specifying no 'output' field would return a similar result (this was just me playing around), but I thought the mongod crash was unexpected.

      When mongod crashes, the following is logged before a backtrace:

      2016-12-13T12:59:10.048+0100 F -        [conn2] Invalid operation at address: 0x7f1d43ba990a
      2016-12-13T12:59:10.061+0100 F -        [conn2] Got signal: 8 (Floating point exception).
      
       0x7f1d443e0f91 0x7f1d443e0089 0x7f1d443e06f6 0x7f1d42153100 0x7f1d43ba990a 0x7f1d43ba91df 0x7f1d43bc8d2e 0x7f1d43bcae3a 0x7f1d43bce255 0x7f1d43ca4492 0x7f1d43a3b0a5 0x7f1d43a3b29c 0x7f1d43a3b893 0x7f1d43d3c31a 0x7f1d43d3cc3b 0x7f1d4398447b 0x7f1d439859a9 0x7f1d438feb2b 0x7f1d438ffd70 0x7f1d43f12afd 0x7f1d43b1c54d 0x7f1d4371082d 0x7f1d4371116d 0x7f1d4435ec22 0x7f1d4214bdc5 0x7f1d41e78ced
      

        1. SERVER-27395.tar.gz
          321 kB
          Tim Vaillancourt

            Assignee:
            david.storch@mongodb.com David Storch
            Reporter:
            tvaillancourt Tim Vaillancourt
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              Created:
              Updated:
              Resolved: