Connections dropped under load
phk at phk.freebsd.dk
Thu Jan 6 01:00:25 CET 2011
In message <4D250296.2000601 at gmail.com>, George Georgovassilis writes:
>1. The benchmark replicates an expected real-life sequence of requests
>and workload from a single IP (namely a corporate web-proxy), thus
>labelling it "synthetic" does it no justice :-)
Well, that depends on your proxy more than anything else, but I'll
take your word for it.
>2. If you leave "session_linger" out of the configuration (so not
>mentioning it at all) the benchmark still hangs. Whatever the default
>value is, it doesn't work and I explicitly need to reduce it to 20.
The default is 50msec.
You can always get the full spiel, inclusive the default value
from the CLI:
session_linger 50 [ms]
Default is 50
How long time the workerthread lingers on the
session to see if a new request appears right
If sessions are reused, as much as half of all
reuses happen within the first 100 msec of the
previous request completing.
Setting this too high results in worker threads
not doing anything for their keep, setting it too
low just means that more sessions take a detour
around the waiter.
NB: We do not know yet if it is a good idea to
change this parameter, or if the default value is
even sensible. Caution is advised, and feedback
is most welcome.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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