I manually complied the master code branch which seems to include the fill-factor features since there are already have some REDWOOD_PAGE_REBUILD_FILL_FACTOR in the master source code like below shown:
fdbserver/VersionedBTree.actor.cpp: state int pageFillTarget = pageSize * SERVER_KNOBS->REDWOOD_PAGE_REBUILD_FILL_FACTOR;
fdbserver/VersionedBTree.actor.cpp: pageFillTarget = pageSize * SERVER_KNOBS->REDWOOD_PAGE_REBUILD_FILL_FACTOR;
fdbserver/Knobs.h: double REDWOOD_PAGE_REBUILD_FILL_FACTOR; // When rebuilding pages, start a new page after this capacity
fdbserver/Knobs.cpp: init( REDWOOD_PAGE_REBUILD_FILL_FACTOR, 0.66 )
so, is it possible to change REDWOOD_PAGE_REBUILD_FILL_FACTOR from foundationdb.conf? and how we can set the customized fill-factor?