Re: [9fans] lsub.org

[erik quanstrom <quanstro@quanstro.net>]

assuming things are broken without external help ....

i've been having trouble with dns infinitely extending
the life of queries when a "srvfail" is returned by an authoratitive
server.  eventually one query to a broken ns will hold up all the threads available
on the server.  this happends a lot on reverse lookups.  i fire this script
every 10 minutes to help ease the pain until i have the time figure out exactly
what's going wrong.

- erik

#!/bin/rc
rfork en
mailuser=guywhogetstocheckonthisstuff
fflag=0
nl='
'
fn usage{
	echo 'usage: restartdns [-f]' >[1=2]
	exit usage
}

fn why{
	if(! ~ $#nbroken 0)
		echo getting mediæval on $#nbroken broken dns processes.
	if not{
		echo getting mediæval on $#nwait deadlocked dns processes.
		for(i in $nwait)
			echo $i
	}
}

for(i)switch($i){
case -f
	fflag=1
case *
	usage
}

if(~ $fflag 0){
	nbroken=`{ps -a | grep dns | grep Broken}
	ifs=$nl nwait=`{ps -a |sed -n 's/.* +dns \[query lock wait for(.*)\]/\1/gp' | sort | uniq -c | awk '$1>2'}

	if(~ $#nbroken 0 && ~ $#nwait 0)
		exit 'none broken'
	why
	if(~ $service rx)
		{date; echo; why; echo; ps -a | grep dns}| mail $guywhogetstocheckonthisstuff
}

slay dns | rc
ndb/dns -s
ndb/dns -Rrsx /net.alt -f /lib/ndb/external