I have an Apache 2.0.54 server on a Linux (2.6.11) box which has 1Gig
RAM and an additional 1Gig swap space. The server handles a lot of
people downloading sermons from our church website (which are generally
about 16-18Meg MP3 files), but I can't figure out how to keep the server
from running out of memory.

Here's my Apache2 prefork configuration:
------------------------------------------------------------------------
<IfModule prefork.c>
StartServers 5
MinSpareServers 5
MaxSpareServers 10
MaxClients 20
MaxRequestsPerChild 5000
</IfModule>


And here's what the Apache "/server-status" URL showed earlier today (I
had just restarted the server, but it immediately filled up with
download requests, all from the same guy, apparently using a download
accelerator judging by the duplicate requests):
------------------------------------------------------------------------
Srv PID M CPU Req Request
0-0 15822 W 0.48 0 GET /out/181.mp3 HTTP/1.1
1-0 15823 W 0.00 1742573500 GET /out/388.mp3 HTTP/1.1
2-0 15824 W 0.00 1742573499 GET /out/238.mp3 HTTP/1.1
3-0 15825 W 0.00 1742573499 GET /out/504.mp3 HTTP/1.1
4-0 15826 W 0.00 1742573496 GET /out/388.mp3 HTTP/1.1
5-0 15832 W 0.00 1742572495 GET /out/801.mp3 HTTP/1.1
6-0 15834 W 0.00 1742571493 GET /out/504.mp3 HTTP/1.1
7-0 15835 W 0.00 1742571489 GET /out/504.mp3 HTTP/1.1
8-0 15838 W 0.00 1742570476 GET /out/388.mp3 HTTP/1.1
9-0 15839 W 0.00 1742570484 GET /out/504.mp3 HTTP/1.1
10-0 15840 W 0.60 0 GET /out/238.mp3 HTTP/1.1
11-0 15841 W 0.00 1742570477 GET /out/388.mp3 HTTP/1.1
12-0 15846 W 0.25 0 GET /out/181.mp3 HTTP/1.1
13-0 15847 W 0.00 1742569347 GET /out/181.mp3 HTTP/1.1
14-0 15848 W 0.00 1742568761 GET /out/801.mp3 HTTP/1.1
15-0 15849 W 0.00 1742568761 GET /out/801.mp3 HTTP/1.1
16-0 15852 W 0.19 0 GET /out/181.mp3 HTTP/1.1
17-0 15853 W 0.17 0 GET /out/801.mp3 HTTP/1.1
18-0 15854 W 0.22 0 GET /out/504.mp3 HTTP/1.1
19-0 15855 W 0.28 0 GET /server-status HTTP/1.1


And here's a portion of what "top" showed at the same time:
------------------------------------------------------------------------
top - 18:09:59 up 64 days, 7:08, 3 users, load avg: 21.62, 10.57, 4.70

Tasks: 154 total, 1 running, 143 sleeping, 1 stopped, 9 zombie
Cpu(s): 0.8% us, 2.3% sy, 0.0% ni, 0.0% id, 96.3% wa, 0.3% hi, 0.2% si
Mem: 1034276k total, 1021772k used, 12504k free, 6004k buffers
Swap: 1030316k total, 985832k used, 44484k free, 83812k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND

15846 apache 16 0 132m 89m 1968 S 0.3 8.9 0:01.46 apache2

15840 apache 17 0 130m 83m 2008 D 0.0 8.3 0:00.90 apache2

15849 apache 16 0 120m 82m 1968 S 0.3 8.1 0:01.02 apache2

15852 apache 16 0 120m 81m 1968 S 0.3 8.1 0:00.91 apache2

15848 apache 16 0 109m 73m 2008 S 0.3 7.2 0:00.85 apache2

15855 apache 16 0 107m 70m 2076 D 0.3 7.0 0:00.76 apache2

15822 apache 17 0 179m 55m 1968 D 0.3 5.5 0:00.88 apache2

15854 apache 16 0 98024 55m 1968 D 0.0 5.5 0:00.58 apache2

15853 apache 18 0 98.9m 53m 2000 S 0.0 5.3 0:00.51 apache2

15847 apache 17 0 86884 52m 1968 D 0.0 5.2 0:00.42 apache2

15841 apache 17 0 110m 36m 1964 D 0.3 3.6 0:00.64 apache2

15826 apache 17 0 173m 20m 1968 D 0.0 2.0 0:00.57 apache2

15825 apache 16 0 97.7m 19m 1968 D 0.0 1.9 0:00.36 apache2

15834 apache 16 0 117m 14m 1968 D 0.3 1.5 0:00.42 apache2

15839 apache 17 0 115m 12m 1968 D 0.0 1.2 0:00.40 apache2

15838 apache 15 0 182m 12m 1968 D 0.0 1.2 0:00.59 apache2

15823 apache 16 0 180m 11m 1968 D 0.0 1.1 0:00.65 apache2

15824 apache 15 0 103m 9980 1968 D 0.0 1.0 0:00.27 apache2

15832 apache 16 0 116m 9112 1968 D 0.0 0.9 0:00.29 apache2

15835 apache 16 0 162m 8844 1968 D 0.0 0.9 0:00.41 apache2
(everything else listed on "top" below this was less than 0.5 for %MEM)


The memory usage swelled very fast as the download requests came in, and
based on previous experience, the server would have slowed to a crawl
and possible crashed as it tried to save itself if I hadn't run "killall
apache2" at this point.

So it seems like this guy's 19 download requests are enough to pretty
much exhaust my 1 Gig of physical RAM and 1 Gig of swap space. That
just doesn't seem right. What am I doing wrong that so few download
requests can bring the server to its knees? How can I fix this
configuration?

Thanks to anyone who can help!