MongoDB 3.4 filesystem challenge: EXT4 vs. XFS

Start mongod on an ext4 data partition and see xfs is strongly recommended over ext4. How does their performance compare?

Connecting to MongoDB v3.4 server on EXT4 fs yields the following warning message:
** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine
We found that on the Raspberry Pi 3 query performance on a 1 million row user collection did not improve using XFS.

About The Data

Collection: 1M Users w/idxs

dbhash: 38389c9d70ebffdf0741c29912a687c0
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Benchmark Methodology

  1. import data (mongorestore)
  2. execute set of pre-defined queries sequentially
  3. obtain query execution times from MongoDB profiling (system.profile)
  4. repeat steps 2 and 3 for a total of 10 times

find where array field length $gt 1

{"$where":"this.pets.length > 1","$comment":"q1"}

rPi3

v3.4 64bit 0 shards EXT4 OpenSUSE Leap 42.2
125,958 ms

rPi3

v3.4 64bit 0 shards XFS OpenSUSE Leap 42.2
133,427 ms

find 'starts with' $regex on string field

{"firstName":{"$regex":"^bill"},"$comment":"q2"}

rPi3

v3.4 64bit 0 shards EXT4 OpenSUSE Leap 42.2
171 ms

rPi3

v3.4 64bit 0 shards XFS OpenSUSE Leap 42.2
154 ms

aggregate $sum

[{"$match":{"$comment":"q3"}},{"$group":{"_id":"$firstName","incomeSum":{"$sum":"$income"}}}]

rPi3

v3.4 64bit 0 shards EXT4 OpenSUSE Leap 42.2
12,443 ms

rPi3

v3.4 64bit 0 shards XFS OpenSUSE Leap 42.2
12,887 ms

find object attribute inside array field

{"videoGames.game":"tomb raider","$comment":"q4"}

rPi3

v3.4 64bit 0 shards EXT4 OpenSUSE Leap 42.2
18,649 ms

rPi3

v3.4 64bit 0 shards XFS OpenSUSE Leap 42.2
20,145 ms

aggregate $avg

[{"$match":{"$comment":"q5"}},{"$group":{"_id":"$firstName","incomeAvg":{"$avg":"$income"}}}]

rPi3

v3.4 64bit 0 shards EXT4 OpenSUSE Leap 42.2
11,484 ms

rPi3

v3.4 64bit 0 shards XFS OpenSUSE Leap 42.2
11,789 ms