Re: FreeBSD and MySQL - mysqld eats CPU alive
removed hackers@, database@ Before the rest of the message ... I think it'd be best not to shotgun your mails like this... Hello. I would disagree with this. This is obviously both database@ and questions@ appropriate. I also feel that it is hackers@ appropriate as it deals with an old, existing, and non-trivial problem that is very much related to FreeBSD. (In fact, reading the URLs you note below, this was almost entirely a FreeBSD internals problem.) It's certain combinations of the two, best I can tell. Looks like you can stay with FBSD if you want to do the tweaking --- be sure and read the second article if your are going to read the first FreeBSD or Linux for your MySQL Server? http://jeremy.zawodny.com/blog/archives/000203.html Revisiting FreeBSD vs. Linux for MySQL http://jeremy.zawodny.com/blog/archives/000697.html Excellent. I had read his earlier notes a long time back, but did not know he had found some solutions to this problem. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
bind 8 slow when resolving new domains!
I am having a big problem with slow internal DNS (bind 8 on FreeBSD 4.9).
If we do a query against a local domain (our DNS server is authoratative)
then the response is fast. If we do a query against anything in bind's
cache the resp. is fast. If we do a query for a new non-local domain then
the resp is SLOW or times-out. FYI, we are behind a NetScreen firewall at
a colo. The colo promises it is not them. Also, we are using their two DNS
servers as forwarders.
The colo promises it's not them, but frankly I can't see how it's us.
# tcpdump -n host ns2 and \( icmp or udp \)
10:07:37.832611 192.168.42.78.53 isp-dns1.53: 4240+ [1au] A?
www.altavista.com. (46)
10:07:51.013213 192.168.42.78.53 isp-dns2.53: 4240+ [1au] A?
www.altavista.com. (46)
10:07:51.074160 isp-dns2.53 192.168.42.78.53: 4240 2/9/10
CNAME[|domain] (DF)
10:07:51.074476 192.168.42.78.53 isp-dns1.53: 17509+ [1au] A?
avatw.search.yahoo2.akadns.net. (59)
10:07:51.131568 isp-dns1.53 192.168.42.78.53: 17509 1/9/10 (393) (DF)
That's a query for www.altavista.com. That took around 13 seconds. I'm
surprised it didn't time-out!
Here is my options {} (more to follow after this):
options {
directory /etc/namedb;
listen-on { 192.168.42.78; };
forward only; // added while troubleshooting
forward first; // added while troubleshooting
forwarders {
isp-dns1;
isp-dns2;
};
allow-transfer {
127.0.0.1;
192.168.42.0/24;
};
fetch-glue no;
// we have a firewall between us and the Internet, so let's
// go ahead and define our query source port
query-source address 192.168.42.78 port 53;
named-xfer /usr/libexec/named-xfer;
};
Okay, so what happens if I try to disable my forwarders?
I now have:
...
// forward only;
// forward first;
//forwarders {
//isp-dns1;
//isp-dns2;
//};
...
So let's try a random domain name:
ns2# nslookup www.looser.com
Server: ns2
Address: 192.168.42.78
*** ns2 can't find www.looser.com: Non-existent host/domain
ns2# nslookup www.looser.com
Server: ns2
Address: 192.168.42.78
Name:www.looser.com
Address: 217.8.158.117
# tcpdump -n host ns2 and \( icmp or udp \)
tcpdump: listening on rl0
10:13:50.515557 192.168.42.78.53 192.33.4.12.53: 21568 [1au] A?
www.looser.com. (43)
10:13:50.562594 192.33.4.12.53 192.168.42.78.53: 21568- 0/13/14 (475)
10:13:50.563816 192.168.42.78.53 192.33.14.30.53: 39445 [1au] A?
www.looser.com. (43)
10:13:50.619570 192.33.14.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:13:50.619641 192.168.42.78.53 192.33.14.30.53: 39445 A?
www.looser.com. (32)
10:13:58.018699 192.168.42.78.53 192.55.83.30.53: 39445 [1au] A?
www.looser.com. (43)
10:13:58.249039 192.55.83.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:13:58.249153 192.168.42.78.53 192.55.83.30.53: 39445 A?
www.looser.com. (32)
10:14:06.018825 192.168.42.78.53 192.41.162.30.53: 39445 [1au] A?
www.looser.com. (43)
10:14:06.051960 192.41.162.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:14:06.052112 192.168.42.78.53 192.41.162.30.53: 39445 A?
www.looser.com. (32)
10:14:09.431353 192.168.42.78.53 192.33.14.30.53: 7462 A?
www.looser.com. (32)
10:14:09.489141 192.33.14.30.53 192.168.42.78.53: 7462- 0/2/2 (109) (DF)
10:14:09.489528 192.168.42.78.53 64.247.9.98.53: 56483 [1au] A?
www.looser.com. (43)
10:14:09.544852 64.247.9.98.53 192.168.42.78.53: 56483*- 1/2/1 A
217.8.158.117 (104) (DF)
10:14:14.018941 192.168.42.78.53 192.43.172.30.53: 39445 [1au] A?
www.looser.com. (43)
10:14:14.160251 192.43.172.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:14:14.160333 192.168.42.78.53 192.43.172.30.53: 39445 A?
www.looser.com. (32)
10:14:22.019082 192.168.42.78.53 192.54.112.30.53: 39445 [1au] A?
www.looser.com. (43)
10:14:22.147459 192.54.112.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:14:22.147543 192.168.42.78.53 192.54.112.30.53: 39445 A?
www.looser.com. (32)
10:14:30.019186 192.168.42.78.53 192.42.93.30.53: 39445 [1au] A?
www.looser.com. (43)
10:14:30.071152 192.42.93.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:14:30.071232 192.168.42.78.53 192.42.93.30.53: 39445 A?
www.looser.com. (32)
10:14:38.019329 192.168.42.78.53 192.31.80.30.53: 39445 [1au] A?
www.looser.com. (43)
10:14:38.052275 192.31.80.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:14:38.052367 192.168.42.78.53 192.31.80.30.53: 39445 A?
www.looser.com. (32)
10:14:46.019458 192.168.42.78.53 192.52.178.30.53: 39445 [1au] A?
www.looser.com. (43)
10:14:46.155902 192.52.178.30.53 192.168.42.78.53: 39445 FormErr- [0q]
0/0/0 (12) (DF)
10:14:46.156056 192.168.42.78.53 192.52.178.30.53: 39445 A?
www.looser.com. (32)
10:14:54.019582 192.168.42.78.53 192.12.94.30.53: 39445 [1au] A?
www.looser.com.
Jails not quite stable..
I am working on a project to move various services running directly under FreeBSD 4.8-REL to run under jails on the same servers. Setting up the jails is no problem at all (I can follow manpages), and bringing the jails up using either '/bin/sh /etc/rc' or '/usr/local/sbin/jailer' works as well. Basically, I can get a jail up and running with the desired service. However, I've found that jails are producing some problems during my testing. 1. On several occassions I have been unable to kill a process in a jail, even with a 'kill -9' from inside or outside the jail as root. europa# ps aux|grep J root 90423 0.0 0.4 1268 920 p0- DJ 10:44PM 0:00.01 /bin/csh europa# kill 90423 europa# ps aux | grep J root 90423 0.0 0.4 1268 920 p0- DJ 10:44PM 0:00.01 /bin/csh europa# kill -9 90423 europa# ps aux | grep J root 90423 0.0 0.4 1268 920 p0- DJ 10:44PM 0:00.01 /bin/csh (If I reboot this machine it will probably hang. See below.) 2. On one occasion (and I haven't attempted to replicate this), I tried a server reboot (with 'reboot') after a jailed process would not die, and the server promptly went offline to never return. I had to have someone hard reset the server. Unfortunately, I am not sure what was on the screen as I wasn't around. I can say though that the server was pingable but not reachable otherwise. 3. If a process is hung, such as /bin/csh, then odd things happen when accessing the location of the jail: # cd /dsk/jails/ # ll total 51684 drwxr-xr-x 13 root wheel 512 Jan 10 22:17 mail1 -rw--- 1 root wheel 52896075 Jan 10 20:47 skel.tgz # cd mail1europa # ll (ls just hangs at this point) I have to kill my ssh session using ~. to get out of this. Note that /dsk/jails/mail1 is not mounted via NFS. It's on the actual local disk. These problems are reproducible across machines running both FreeBSD 4.8-REL and FreeBSD 4.9-STABLE: # uname -v FreeBSD 4.9-STABLE #0: I WANT to use jails to host most of our services, if for no other reason than the increase manageability, but there just seems to be a stability issue here. I realize I will get a lot of It works for me, but again, these problems are reproducible, so I'm sure someone else has seen it. :) Thoughts on this? ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
