add backoff to updating the current cache
make sure table index worker does not attempt to create table if current cache too far behind
Merge pull request #1511 from marcel-blonk/PLFM-3009

add backoff to updating the current cache
test fix
Merge pull request #1512 from marcel-blonk/PLFM-3009

test fix
Merge remote-tracking branch 'upstream/develop' into PLFM-2580