Both client and server run on a Dell Inspiron 8100, 1Ghz running RedHat 7.2.
On this machine I got OTP-R8-0 configured and compiled in the default way.
Each test was made by letting the client spew out GET requests for a small
(372 bytes) static page as fast as it could and then
continue until I had received 20000 responses. Only responses with a status
code of 200 was seen as ok. Default httpd.conf have been used (same for
inets-3.0 and inets 2.6), but MaxClients was increased to 150 for inets (equal
as for default in the Apache configuration). 
In the non-persistent case I let the test client spawn new connections until I
had a maximum number of open connections. In the persistent case I additionally
used a pipeline size of max 2. 




- Error Reason 503 means that I received a response with status 503 (HTTP server
temporary overload),
- closed, ???
- einval, ???
- enfile (out of Ports),
- etimedout (TCP session timeout)
are all errors received from gen_tcp:connect/3, gen_tcp:send/2 and
gen_tcp:close/1 and when receiving data.
Finally, timeout is generated internally in the client.


****** inets-3.0a client and inets-3.0a server
+Persistent connection (85.8870 ok response/s)
Total responses:20000: time:00:01:55 response/s:173.913
  9877 ok 10123 error responses
  Error Reason: 503: 5470 
  Error Reason: closed: 2453 
  Error Reason: einval: 2200 

+Non Persistent connection (66.0182 ok response/s)
Total responses:20000: time:00:00:55 response/s:363.636
  3631 ok 16369 error responses
  Error Reason: 503: 14285 
  Error Reason: closed: 741 
  Error Reason: einval: 1339 
  Error Reason: {enfile,[{erlang,open_port_prim,[{spawn,tcp_inet},[binary]]},
                         {prim_inet,open0,1},
                         {prim_inet,open1,2},
                         {inet,open,7},
                         {inet_tcp,do_connect,4},
                         {gen_tcp,try_connect,6},
                         {gen_tcp,connect,4},
                         {http,handle_new_connection,2}]}: 4 

****** inets-3.0a client and inets-2.6 server
+Non Persistent connection (62.1299 ok response/s)
Total responses:20000: time:00:04:14 response/s:078.740
  15781 ok 4219 error responses
  Error Reason: 503: 55 
  Error Reason: etimedout: 104 
  Error Reason: timeout: 2807 
  Error Reason: {enfile,[{erlang,open_port_prim,[{spawn,tcp_inet},[binary]]},
                         {prim_inet,open0,1},
                         {prim_inet,open1,2},
                         {inet,open,7},
                         {inet_tcp,do_connect,4},
                         {gen_tcp,try_connect,6},
                         {gen_tcp,connect,4},
                         {http,handle_new_connection,2}]}: 1253 


****** inets-3.0a client and Apache 1.3.22 server
+Persistent connection (1250.00)
Total responses:20000: time:00:00:16 response/s:1250.000
  20000 ok 0 error responses

+Non Persistent connection (791.520)
  Total responses:20000: time:00:00:25 response/s:800.000
  19788 ok 212 error responses
  Error Reason: closed: 212