We have notices a large journal file buildup when using WiredTiger.
We are pushing a lot of test data into Mongo to test the performance.
We did notice that the WiredTiger journal files are not deleted and just left in the /journal dir when we are pushing the data.
The files are deleted when we stop pushing any new data to the Mongo, but in the production environment it wouldn't happen.
From my understanding of the documentation the journal files would be flushed frequently, not left on the disk indefinitely.
We are using MongoDB 3.2 on FreeBSD 10.1. The files are on zfs, with atime disabled. We are using zlib on both journal files and data files, but we did see the same issue with snappy.
Currently we have ~520 journal files, and growing every second. They are taking 16GB of space at the moment.
Is is normal? I believe it is a bug, there should be a way to limit the number of journal files.