Re: How DBA solved overload problem ?
As a newly DBA, I really don't know how I deal with this problem. My problem is not so long ago, my database server seem to overloaded. It take me a time to find the cause of problem. I realize that some program don't queried wiht inappropriated SQL statement. I mean they're not efficient one. AS DBA how do you solved this problem? In PostgreSQL, I flip on the following settings and then periodically scan PostgreSQL's the log file (/var/log/pgsql): log_duration = true log_pid = true log_statement = true log_timestamp = true It's tedious, but with grep on your side, it's not an impossible task or even a super hard one... just a bit tedious if you don't keep up with your developers. I've found doing this on the devel machines produces better bang for the buck than on the production DB's (though I still do it there occasionally). Once a query is found, I typically launch a big 'ole fashion egrep -r with a reasonably unique part of the query and am normally pretty successful in finding the culprit. Sometimes you'll have to use sockstat to find what machine and what PID you're dealing with, but that's something I have to do rarely. -sc PS Don't spam so many lists in the future, just -databases or just -questions would've been sufficient (the more topical the list the better). -- Sean Chittenden ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Performance Problems.. Server hardware smoked by $500 box?
Post your kernel configs, or better yet, do a diff -u between the 5.0-R and the 5.1-C kernel configs. I bet dime to dollar you've got some debugging options enabled in the 5.1-C config. At the very least you haven't remove the debugging options from your malloc options. *frown* The 5.0 development machine is running GENERIC. Being that we never customized the kernel, we don't have a backup copy of it. I can say since I'd have been the one to change it, that the only differences between GENERIC and what we put into service is that we always remove the device listings for things we don't have any use for, like ISA nic's and such. I almost never change any of the other features. Removing unused drivers shouldn't make any difference. If 5.1-C has debugging on by default then , yes, I'd concur that we have those features turned on. However the production machine was 4.8-R when we noticed the problem. From what it sounds, it should have been faster due to that fact. The only thing that's been constant in this situation is that the development machine hasn't changed. Everything I've done has been trying to change variables on the production machine to either match or surpass the development to bring it up to it's speed. hrm... On your development box, do you have any boot time configuration options set, how about differing values in sysctl.conf? Hrm, let me re-read your original post. Apache: Are you sure you have your reverse DNS setup correctly? Are you doing host name resolution in Apache for your logs? If so, turn that off! bonnie: It's very possible that the CPU is making a difference here if bonnie is getting near 100% hit rates for the cache. Given that you're getting good throughput, I'd double check that you're machines are at 100Mbps-TX, full duplex in ifconfig. I bet one of them is half-duplex and that's the difference there. I'm betting there are some sysctl's that are different between these machines, along with possibly Apache and your DNS not being setup correctly. Roadmap for the production machine so far: Upgrade apache/php to newest in ports. I haven't seen anyone claim that Apache2 is faster than Apache 1. If Apache2 is faster, could someone provide some evidence? Add RAM This won't make a difference unless you're swapping our out of RAM. Upgrade OS to 5.1 from 4.8, reinstall every package in pkg_info Downgrade you mean? :) 4.8 is going to be more battle proven than 5.1, so I'd recommend using 4.8 for that reason alone. If you do want to use 5.1 for the sake of helping 5.1 become more mature, very cool. Update apache to 2.X from 1.3.X reinstall php as is required See above comment on Apache. Swap network interfaces between the two onboard ones This could make some difference, but 6MBps is more than plenty throughput for webserving via NFS. Swap ethernet cables with the development machine This would impact network performance, something else is going on. Swap ethernet ports with the development machine Again, this would impact network performance, and at 6MBps, that's well more than enough for you to get reasonable performance out of a 5.1 or 4.8 box. Something basic and simple is going on here. DNS: dig my.test.box.example.com. a dig d.c.b.a.in-addr.arpa. ptr apache: grep Hostname /usr/local/etc/apache/httpd.conf -sc -- Sean Chittenden ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
ipfilter per rule ttl's not working?
Since ipf doesn't send keep alives to refresh its connections and on our Intranet server that gets modest www traffic, how can I run with reasonably low/sane TTLs for most of our rules, but have a different TTL for ssh traffic? The documentation suggests that I can do this: filter-rule = [ insert ] action in-out [ options ] [ tos ] [ ttl ] [ proto ] [ ip ] [ group ]. ttl = ttl decnumber . But in practice, I think that the feature is unable to correctly identify a valid number when it sees one. From ipf.rules: pass in quick on fxp1 ttl 604800 proto tcp from any to 192.168.1.0/24 port = 22 flags S keep state keep frags # ipf -Fa -f /etc/ipf.rules 693: invalid ttl (604800) :-/ One would think that 604800 would qualify as a decnumber. Am I missing something or is this a documented non-feature? -sc -- Sean Chittenden ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Disk cache size via sh?
Is the following the correct way to figure out the disk cache size? echo $((`sysctl -n vm.stats.vm.v_page_count` - \ `sysctl -n vm.stats.vm.v_free_reserved` - \ `sysctl -n vm.stats.vm.v_free_target`)) I can't tell if there's a limit in kern/vfs_cache.c though I couldn't find anything worth while. -sc -- Sean Chittenden ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Disk cache size via sh?
Is the following the correct way to figure out the disk cache size? echo $((`sysctl -n vm.stats.vm.v_page_count` - \ `sysctl -n vm.stats.vm.v_free_reserved` - \ `sysctl -n vm.stats.vm.v_free_target`)) I can't tell if there's a limit in kern/vfs_cache.c though I couldn't find anything worth while. More correctly, can the FS cache up to the entire size listed in vfs.maxbufspace (actually vfs.hibufspace) bytes or is there a limit to how much FS operations can use of the vfs cache? -sc -- Sean Chittenden ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: gcc me harder: -Wconversion bug?
It seems to me that this is doing exactly what is claimed for -Wconversion.
To quote from the gcc man page:
-Wconversion
Warn if a prototype causes a type conversion that
is different from what would happen to the same ar-
gument in the absence of a prototype. ...
Now in the absence of a prototype for f() the argument true would be
promoted from char/bool to int before being passed to the
function. With the prototype in scope it is not promoted. Different
argument widths so warning delivered.
% cpp test.c
# 1 test7.c
# 1 built-in
# 1 command line
# 1 test7.c
# 1 test7.h 1
# 13 test7.h
void f(char b);
# 2 test7.c 2
int
main(int argc, char *argv[]) {
fchar)1)));
return(0);
}
void
f(char b) {
}
Am I missing something that says that there isn't the prototype of the
same width? Last time I checked my vision, f(char b) was the same as
f(char b)... :-/ or am I missing something? I believe that gcc's
promoting the char to an int or to some other non-1 byte width data
type... but I'm not seeing how, where, or why. -sc
--
Sean Chittenden
___
[EMAIL PROTECTED] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to [EMAIL PROTECTED]
gcc me harder: -Wconversion bug?
[ Please CC: me on replies, not on questions@ ]
Is this a GCC bug with the -Wconversion flag or am I doing something
wrong? I know it's just a warning, but it's irritating me more than
that dumb Dan Quayle quote, if it weren't for that horse, I wouldn't
have spent an extra year in college... -sc
% gcc -v
Using built-in specs.
Configured with: FreeBSD/i386 system compiler
Thread model: posix
gcc version 3.2.2 [FreeBSD] 20030205 (release)
% uname -a
FreeBSD hostname.example.com 5.1-CURRENT FreeBSD 5.1-CURRENT #2: Mon Jun 9 12:23:34
PDT 2003 [EMAIL PROTECTED]:/usr/src/sys/i386/compile/HOSTNAME i386
% gcc -Wconversion test.c
test.c: In function `main':
test.c:5: warning: passing arg 1 of `f' with different width due to prototype
/* Begin test.h */
#ifndef __TEST_H__
#define __TEST_H__
#ifndef bool
typedef char bool;
#endif
#ifndef true
#define true((bool)1)
#endif
#ifndef false
#define false ((bool)0)
#endif
void f(bool b);
#endif
/* End test.h */
/* Begin test.c */
#include test.h
int
main(void) {
f(true);
return(0);
}
void
f(bool b) { }
/* End test.c */
--
Sean Chittenden
___
[EMAIL PROTECTED] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to [EMAIL PROTECTED]
Number of sf_bufs (nsfbuf)'s available/inuse for -STABLE...
Is there any way to determine if there are any sf_buf's available or how many are in use under -STABLE? I know -CURRENT has kern.ipc.nsfbufs as a read only tunable, but that doesn't tell me how many are free. Anyone else use sendfile(2) extensively and have pearls of wisdom in terms of performance tuning? -sc -- Sean Chittenden pgp0.pgp Description: PGP signature
