mysql - Benchmarking Apache

I'm benchmarking Apache/2.2.3 (prefork) using ab and siege with the following command:

ab -kc 200 -t 120 http://www.mywebsite.com/test.php
siege -c200 -t2M http://www.mywebsite.com/test.php

test.php is a very simple file which just creates one mysql connection and then closes

$link = mysql_connect("localhost", "username", "password");
mysql_select_db("dbname");
if(!$link) {
    die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
?>

The results I get have a lot of failed requests in them. I'm trying to figure out how to go about reducing the number of these failed requests since this is a fairly simple script, server load is quite low, I shouldn't have a problem on a Quad-Core Xeon 3Ghz machine with 8G of RAM.

Output from siege

Transactions:               9438 hits
Availability:              98.33 %
Elapsed time:             119.39 secs
Data transferred:           0.38 MB
Response time:             1.31 secs
Transaction rate:          79.05 trans/sec

Throughput:               0.00 MB/sec
Concurrency:                  103.37
Successful transactions      9438
Failed transactions:          160
Longest transaction:        21.24
Shortest transaction         0.21

Output from ab:

Benchmarking www.mywebsite.com (be patient)

Server Software:        Apache/2.2.3
Server Hostname:        www.mywebsite.com
Server Port:            80  

Document Path:          /test.php
Document Length:        22 bytes

Concurrency Level:      200 

Time taken for tests:   35.851520 seconds
Complete requests:      50000
Failed requests:        618
   (Connect: 0, Length: 618, Exceptions: 0)
Write errors:           0   
Keep-Alive requests:    49600
Total transferred:      12932098 bytes
HTML transferred:       1149345 bytes
Requests per second:    1394.64 [#/sec] (mean)
Time per request:       143.406 [ms] (mean)

Time per request:       0.717 [ms] (mean, across all concurrent requests)
Transfer rate:          352.26 [Kbytes/sec] received

A quick highlight of my Apache Configuration

Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 15



StartServers 20
MinSpareServers 20
MaxSpareServers 50
ServerLimit 500
#default 200
MaxClients 500
MaxRequestsPerChild  4000

I ran the same test with the same script on another weaker server, and it had zero failed requests and finished tests faster. So I wonder what's wrong on this one.

Updated MySQL configuration:

Variables

mysql> show variables LIKE '%connect%';
+--------------------------+-------------------+

| Variable_name            | Value             |
+--------------------------+-------------------+
| character_set_connection | latin1            | 
| collation_connection     | latin1_swedish_ci | 
| connect_timeout          | 10                | 
| init_connect             |                   | 
| max_connect_errors       | 10                | 
| max_connections          | 100               | 
| max_user_connections     | 0                 | 
+--------------------------+-------------------+

Global Status

mysql> SHOW GLOBAL STATUS LIKE '%connect%';
+--------------------------+---------+
| Variable_name            | Value   |
+--------------------------+---------+
| Aborted_connects         | 343     | 
| Connections              | 1463797 | 

| Max_used_connections     | 101     | 
| Ssl_client_connects      | 0       | 
| Ssl_connect_renegotiates | 0       | 
| Ssl_finished_connects    | 0       | 
| Threads_connected        | 3       | 
+--------------------------+---------+