Critical Description
I have a test setup using lighttpd (stock config, but with the port changed to port 82, and logging disabled). I've created a small file (42 bytes) in /var/www/lighttpd/cl-test.html.
I'm running Apache TS with a stock config ("gmake install") with the following configuration changes:
records.config:
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CONFIG proxy.config.http.server_port INT 80
CONFIG proxy.config.http.cache.required_headers INT 2
CONFIG proxy.config.log2.logging_enabled INT 0
remap.config:
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map http://loki.ogre.com/lighttpd/ http://localhost:82/
I'm "benchmarking" this using "ab" from a second host, running a command like
ab -c 20 -n 10000 http://loki.ogre.com/lighttpd/cl-test.html
Test 1: I disable Keep-Alive in lighttpd, adding a configuration like this to /etc/lighttpd/lighttpd.conf:
server.max-keep-alive-requests = 0
Test results are
Requests per second: 9056.01 /sec (mean)
Time per request: 2.208 [ms] (mean)
Time per request: 0.110 [ms] (mean, across all concurrent requests)
Test 2: I enable Keep-Alive in lighttpd, with
server.max-keep-alive-requests = 1000000
Test results are:
Requests per second: 4456.33 /sec (mean)
Time per request: 4.488 [ms] (mean)
Time per request: 0.224 [ms] (mean, across all concurrent requests)
This might not seem like a huge difference, but why would it be serving 2x fewer QPS and 2x the latency with keep-alive to the origin server? If anything, I'd expect it to be faster with keep-alive, right ? Shouldn't that be noticeably less work?