Major - P3 We have a collection with powerOf2 and a TTL index. The collection takes a lot of inserts of large documents (4-16MB) which are deleted by the TTL in 30 hours. There are no updates.
The dataSize of the collection is roughly constant, but over time we see the fileSize and storageSize grow reaching 20x of dataSize.
My understanding is that this has to do with how the freelist is managed for documents >4MB with powerOf2 enabled.
A repro test attached.
Output:
$ mongo localhost:26010/frag_test fragmentation.js MongoDB shell version: 2.6.0 connecting to: localhost:26010/frag_test Before inserts. Filesize: 0, storageSize: 0 Iteration 1, Filesize: 3102736384, storageSize: 2526687200 Iteration 2, Filesize: 4175953920, storageSize: 3599888320 Iteration 3, Filesize: 5785780224, storageSize: 5209690000 Iteration 4, Filesize: 6858997760, storageSize: 6282891120 Iteration 5, Filesize: 8468824064, storageSize: 7892692800 Iteration 6, Filesize: 9542041600, storageSize: 8965893920 Iteration 7, Filesize: 10615259136, storageSize: 10039095040 Iteration 8, Filesize: 12225085440, storageSize: 11648896720
- is duplicated by
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SERVER-15025 Disk usage increases linearly with constant data size, large churn, usePowerOf2Sizes and large document sizes
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- Closed
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