I found that UfsSyncPathCache.java:68 parameter had no effect. When I debugged after set this parameter, I found that lastSync of the path that I got from cache was always null.
It seems that the pathsToLoad of DefaultFileSystemMaster.java:3345 was always null, so the cache was never refreshed. I don't know if I set it right?
My alluxio version: 1.8.1.
Thanks.
I suspect you are hitting a known issue. See the following github issue.
https://github.com/Alluxio/alluxio/issues/8531
This can result in Alluxio accessing UFS unnecessarily in subsequent listStatus calls.
It has been fixed in the master branch and the latest 2.0 releases. The fix has been back ported to the 1.8 branch.
https://github.com/Alluxio/alluxio/pull/8561
You can try to checkout branch-1.8 from the github to try it out or move to the 2.0-preview release.