| Reduce Load in VZs [message #43168] |
Wed, 03 August 2011 06:55  |
<me
Messages: 4
Registered: August 2011
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Junior Member |
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Hello,
We have on our Server about 17VZs installed and running. Most of them run
simmilar cron jobs, e.g. apticron and this causes very high load at night.
Is there any best practise that we can use to reduce the load with these
jobs? I tought about running these cronjobs from outside with vzctl exec
(so make a cron at the host and just start the programms manually) and run
only 1 job at once.
In general: Is there a best practise to run things in every VZ and not
produce high load?
Thanks!
greetings
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| Re: Reduce Load in VZs [message #43171 is a reply to message #43170] |
Wed, 03 August 2011 08:10  |
<me
Messages: 4
Registered: August 2011
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Junior Member |
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On Wed, 03 Aug 2011 11:47:05 +0400, Kir Kolyshkin <kir@openvz.org> wrote:
> Interesting. vzctl does crontab randomization, by means of
> /etc/vz/dists/scripts/vps-postcreate.sh
> script, so the question is why it is not working. I can see a few
> reasons why it's not working as it should:
>
> (1) CT was created not by vzctl
mh it was, all of them are created by this script
> (2) CT has been upgraded from the inside, so /etc/crontab was being
> modified
yes, the cronjobs are under /etc/cron.{daily,weeky,...}
> (3) CT has a distro installed which has crontab in some unusual location
no its running debian lenny or squeeze or sid
> (4) Some other bug?
mh could be, we try now different things to encounter the problem... seems
very complicated at the moment because we have really no idea whats going
on there
greetings!
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| Re: [PATCH] Reduce Load in VZs - stop cron.d thundering herd... [message #43172 is a reply to message #43170] |
Wed, 03 August 2011 08:29 |
Tim Small
Messages: 24
Registered: April 2011
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Junior Member |
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On 03/08/11 08:47, Kir Kolyshkin wrote:
>
> (3) CT has a distro installed which has crontab in some unusual location
Nearly (3)
/etc/cron.d is a standard location, but vps-postcreate.sh didn't deal
with it.
I thought I'd submitted this patch to debian, but I seem to have dropped
it :-(
Tim.
--- postcreate.sh.old 2010-09-14 06:07:31.000000000 +0100
+++ /etc/vz/dists/scripts/postcreate.sh 2011-08-03 09:27:22.490356610 +0100
@@ -24,12 +24,12 @@
function randcrontab()
{
- file=${VE_ROOT}"/etc/crontab"
+ for file in ${VE_ROOT}/etc/cron.d/* ${VE_ROOT}/etc/crontab
+ do
+ [ -f "${file}" ] || return 0
- [ -f "${file}" ] || return 0
-
- /bin/cp -fp ${file} ${file}.$$
- cat ${file} | awk '
+ /bin/cp -fp ${file} ${file}.$$
+ cat ${file} | awk '
BEGIN { srand(); }
{
if ($0 ~ /^[ \t]*#/ || $0 ~ /^[ \t]+*$/) {
@@ -61,8 +61,9 @@
}
print line;
}
-' > ${file}.$$ && /bin/mv -f ${file}.$$ ${file}
- /bin/rm -f ${file}.$$ 2>/dev/null
+ ' > ${file}.$$ && /bin/mv -f ${file}.$$ ${file}
+ /bin/rm -f ${file}.$$ 2>/dev/null
+ done
}
function disableroot()
--
South East Open Source Solutions Limited
Registered in England and Wales with company number 06134732.
Registered Office: 2 Powell Gardens, Redhill, Surrey, RH1 1TQ
VAT number: 900 6633 53 http://seoss.co.uk/ +44-(0)1273-808309
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| Re: Reduce Load in VZs [message #43173 is a reply to message #43171] |
Wed, 03 August 2011 08:32 |
Tim Small
Messages: 24
Registered: April 2011
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Junior Member |
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On 03/08/11 09:10, me@free-minds.net wrote:
>
>> (2) CT has been upgraded from the inside, so /etc/crontab was being
>> modified
>>
> yes, the cronjobs are under /etc/cron.{daily,weeky,...}
>
Compare /etc/crontab between containers - the entries should have
different (randomized) times:
# m h dom mon dow user command
17 * * * * root cd / && run-parts --report /etc/cron.hourly
25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts
--report /etc/cron.daily )
47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts
--report /etc/cron.weekly )
52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts
--report /etc/cron.monthly )
... if they are, then perhaps it's /etc/cron.d/* tabs instead? This was
the problem on my client's system.
Tim.
--
South East Open Source Solutions Limited
Registered in England and Wales with company number 06134732.
Registered Office: 2 Powell Gardens, Redhill, Surrey, RH1 1TQ
VAT number: 900 6633 53 http://seoss.co.uk/ +44-(0)1273-808309
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| Re: [PATCH] Reduce Load in VZs - stop cron.d thundering herd... [message #43174 is a reply to message #43172] |
Wed, 03 August 2011 08:33 |
<me
Messages: 4
Registered: August 2011
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Junior Member |
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awesome thanks, i'll try it. So best is i copy all the stuff from
cron.daily to cron.d and add 0 0 * * * ar @daily at the beginning, or is it
the same to leave them there and these things will allready called by cron?
On Wed, 03 Aug 2011 09:29:32 +0100, Tim Small <tim@seoss.co.uk> wrote:
> On 03/08/11 08:47, Kir Kolyshkin wrote:
>>
>> (3) CT has a distro installed which has crontab in some unusual
location
>
> Nearly (3)
>
> /etc/cron.d is a standard location, but vps-postcreate.sh didn't deal
> with it.
>
> I thought I'd submitted this patch to debian, but I seem to have dropped
> it :-(
>
> Tim.
>
> --- postcreate.sh.old 2010-09-14 06:07:31.000000000 +0100
> +++ /etc/vz/dists/scripts/postcreate.sh 2011-08-03 09:27:22.490356610
+0100
> @@ -24,12 +24,12 @@
>
> function randcrontab()
> {
> - file=${VE_ROOT}"/etc/crontab"
> + for file in ${VE_ROOT}/etc/cron.d/* ${VE_ROOT}/etc/crontab
> + do
> + [ -f "${file}" ] || return 0
>
> - [ -f "${file}" ] || return 0
> -
> - /bin/cp -fp ${file} ${file}.$$
> - cat ${file} | awk '
> + /bin/cp -fp ${file} ${file}.$$
> + cat ${file} | awk '
> BEGIN { srand(); }
> {
> if ($0 ~ /^[ \t]*#/ || $0 ~ /^[ \t]+*$/) {
> @@ -61,8 +61,9 @@
> }
> print line;
> }
> -' > ${file}.$$ && /bin/mv -f ${file}.$$ ${file}
> - /bin/rm -f ${file}.$$ 2>/dev/null
> + ' > ${file}.$$ && /bin/mv -f ${file}.$$ ${file}
> + /bin/rm -f ${file}.$$ 2>/dev/null
> + done
> }
>
> function disableroot()
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| Re: Reduce Load in VZs [message #43175 is a reply to message #43173] |
Wed, 03 August 2011 08:35 |
<me
Messages: 4
Registered: August 2011
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Junior Member |
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Hi,
Ah yes, Im a fool :D - forget the mail from before...
i'll see what i can get there and will try the patch!
thank you both!
greetings
On Wed, 03 Aug 2011 09:32:47 +0100, Tim Small <tim@seoss.co.uk> wrote:
> On 03/08/11 09:10, me@free-minds.net wrote:
>>
>>> (2) CT has been upgraded from the inside, so /etc/crontab was being
>>> modified
>>>
>> yes, the cronjobs are under /etc/cron.{daily,weeky,...}
>>
>
> Compare /etc/crontab between containers - the entries should have
> different (randomized) times:
>
> # m h dom mon dow user command
> 17 * * * * root cd / && run-parts --report /etc/cron.hourly
> 25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts
> --report /etc/cron.daily )
> 47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts
> --report /etc/cron.weekly )
> 52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts
> --report /etc/cron.monthly )
>
>
>
> ... if they are, then perhaps it's /etc/cron.d/* tabs instead? This was
> the problem on my client's system.
>
> Tim.
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