I'd suggest to also close the following issue: * SVN-4557: ra_serf fails to delete directory containing many files https://issues.apache.org/jira/browse/SVN-4557The fix for this particular issue got in 1.9.4 and even though it's not yet backported to the 1.8 branch, the described issue is fixed in 1.9 now.
-- Regards, Stefan Hett