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Apache HTTP Server Version 1.3
Hints on Running a High-Performance Web Server
Running Apache on a heavily loaded web server, one often encounters problems related to the
machine and OS configuration. "Heavy" is relative, of course - but if you are seeing
more than a couple hits per second on a sustained basis you should consult the pointers on
this page. In general the suggestions involve how to tune your kernel for the heavier TCP
load, hardware/software conflicts that arise, etc.
If you are running Apache on A/UX, a page that gives some helpful performance hints
(concerning the listen() queue and using virtual hosts)
can be found here
Quick and detailed performance
tuning hints for BSD-derived systems.
Accept filtering on FreeBSD.
- Solaris 2.x - tuning your TCP/IP stack
contains some good technical information about tuning various Solaris TCP/IP parameters.
More information on tuning SOMAXCONN on SunOS can be found at http://www.islandnet.com/~mark/somaxconn.html.
Some SVR4 versions waste three system calls on every gettimeofday() call.
Depending on the syntactic form of the TZ environment variable, these systems
have several different algorithms to determine the local time zone (presumably compatible
with something). The following example uses the central european time zone to demonstrate
this:
- TZ=:MET
- This form delegates the knowledge of the time zone information to an external compiled
zoneinfo file (à la BSD).
Caveat: Each time the gettimeofday() function is called, the external
zone info is read in again (at least on some SVR4 systems). That results in three wasted
system calls with every apache request served.
open("/usr/lib/locale/TZ/MET", O_RDONLY) = 3
read(3, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 7944) = 778
close(3) = 0
- TZ=MET-1MDT,M3.5.0/02:00:00,M10.5.0/03:00:00
- This syntax form (à la SYSV) contains all the knowledge about time zone beginning and
ending times in its external representation. It has to be parsed each time it is
evaluated, resulting in a slight computing overhead, but it requires no system call.
Though the table lookup à la BSD is the more sophisticated technical solution, the bad
SVR4 implementation makes this the preferred syntax on systems which otherwise access the
external zone info file repeatedly.
You should use the truss utility on a single-process apache server (started with
the -X debugging switch) to determine whether your system can profit from the
second form of the TZ environment variable. If it does, you could integrate the
setting of the preferred TZ syntax into the httpd startup script, which is
usually simply a copy of (or symbolic link to) the apachectl utility script, or
into the system's /etc/TIMEZONE script.
Reviews of insomnia cure for sleeping problems.
How to obtain better gas mileage for your car.
Using a good wedding budget planner to have a
great wedding.
More welcome!
If you have tips to contribute, please submit them to the Apache
Bug Database.
Apache HTTP Server Version 1.3
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