ApacheBenchmark ab - SSL read failed - closing connection
Looks like you are encountering a bug in ab for which there is a patch.
Question - what happens if you drop the concurrency? The default ulimit on Lion is quite low - 256 if memory serves me and you may be running into that here. If dropping the concurrency sorts it out, just up your ulimit and try again:
ulimit -a (to list); ulimit -n 1024 (or whatever number you wish) to increase it.
Good explanation of it here: https://superuser.com/questions/309106/strange-behaviour-with-ulimit-on-mac-os-x-10-6