There are currently no dtests for the new cdc feature. We should have some, at least to ensure that the cdc files have a lifecycle that makes sense, and make sure that things like a continually cleaning daemon and a lazy daemon have the properties we expect; for this, we don't need to actually process the files, but make sure they fit the characteristics we expect from them. A more complex daemon would need to be written in Java.
I already hit a problem where if the cdc is over capacity, the cdc properly throws the WTE, but it will not reset after the overflow directory is undersize again. It is supposed to correct the size within 250ms and allow more writes.