+1 for the patch. It looks like a clean backport.
[exec] -1 tests included. The patch doesn't appear to include any new or modified tests.
[exec] Please justify why no tests are needed for this patch.
I tested the patch manually by building the distro and running 1 each of NN, DN, and 2NN. I accessed the 2NN's web UI and ran some file system operations. I saw the 2NN checkpoint successfully, and I verified that the web UI updated the displayed information about the last checkpoint.
Thanks for doing the backport, Nicholas!