I am Pavel Jurkas from wialus.co.nz. We use your eblob library (the current version 0.21.40)
in one of our applications that creates a lot of small files.
Your library really helped us to solve the problem with too many small files using too many i-nodes in the filesystem.

We found a problem when stopping our service. Closing eblob (eblob_cleanup()) takes too long.
The delay is caused by using sleep() function calls in maintenance threads (sync, defrag, and periodic threads).
We use 5 seconds period for sync threads in our eblobs. It means there is 2.5 seconds delay per closing one eblob on average.
Our service uses several eblobs, so closing them can take some time.
example: removed embed application
v0.21.41
cmake: removed unused boost_program_options deps
eblob: added lrt library, clock_gettime() lives there