16 Bře
2018
16 Bře
'18
10:55
Aleš,
On 03/16/2018 10:32 AM, Aleš Rygl wrote:
Hi Daniel, hi all.
I completely agree that VmSize is not the right metric and I was not mentioning it in my
original post :-) I'd rather point out that Knot is in my case consuming nearly 2Gig
of RAM while serving just 141 zones with 1MB of records while Bind serving 1560 zones (10%
on DNSSEC) something about 550MB =-O
root@eira:~# free -h
total used free shared buff/cache available
Mem: 2.0G 1.7G 122M 5.4M 126M 109M
Swap: 0B 0B 0B
root@eira:~#
root@eira:~# systemctl stop knot.service
root@eira:~#
root@eira:~# free -h
total used free shared buff/cache available
Mem: 2.0G 54M 1.8G 5.4M 126M 1.8G
Swap: 0B 0B 0B
root@eira:~#
Is it something what I have to count on when using Knot? I am just surprised by such
memory requirements and your measurement shows that it is like that. I will have to add
some RAM...
Probably I don't understand. Knot consumed less physical memory than Bind during my
test :-)
To be honest, I don't understand why Knot is consuming such amount of memory in your
case!
Could you please try disabling the statistics module? Statistics per zone with all metrics
consume
some memory.
Daniel
Thanks for memory saving tips.
BR
Ales
On 15.3.2018 21:16, daniel.salzman(a)nic.cz wrote:
Hi Aleš,
I would agree with Vladimír. Virtual memory consumption is not
important. We should focus on physical memory consuption (VmRSS).
But in your case, these values are almost equal. It's very strange!
I did a quick measurement:
TLD with DNSSEC | 10k zones with DNSSEC
VIRT RES | VIRT RES
--------------------------------+-----------------
Bind 9.12.1 656M 419M | 1269M 152M
Knot 2.6.5 4384M 360M | 4588M 39440
NSD 4.1.20 124M 87216 | 147M 108M
1759M 1732M | 115M 89124
Note1: I don't know how NSD work, so I printed 2 top level processes.
Note2: Bind was compiled with --enable-threads.
The virtual memory consumption by Knot can be significantly reduced by
setting max-timer-db-size, max-journal-db-size, max-kasp-db-size, and
--with-conf-mapsize configure option (if compiled from the source code).
Best,
Daniel
On 2018-03-15 13:37, Aleš Rygl wrote:
> Dear all,
>
> While trying to migrate or DNS to Knot I have noticed that a slave
> server with 2GB RAM is facing memory exhaustion. I am running
> 2.6.5-1+0~20180216080324.14+stretch~1.gbp257446. There is 141 zones
> having around 1MB in total. Knot is acting as pure slave server with
> minimal configuration.
>
> There is nearly 1.7GB of memory consumed by Knot on a freshly rebooted server:
>
> root@eira:/proc/397# cat status
> Name: knotd
> Umask: 0007
> State: S (sleeping)
> Tgid: 397
> Ngid: 0
> Pid: 397
> PPid: 1
> TracerPid: 0
> Uid: 108 108 108 108
> Gid: 112 112 112 112
> FDSize: 64
> Groups: 112
> NStgid: 397
> NSpid: 397
> NSpgid: 397
> NSsid: 397
> VmPeak: 24817520 kB
> VmSize: 24687160 kB
> VmLck: 0 kB
> VmPin: 0 kB
> VmHWM: 1743400 kB
> VmRSS: 1743272 kB
> RssAnon: 1737088 kB
> RssFile: 6184 kB
> RssShmem: 0 kB
> VmData: 1781668 kB
> VmStk: 132 kB
> VmExe: 516 kB
> VmLib: 11488 kB
> VmPTE: 3708 kB
> VmPMD: 32 kB
> VmSwap: 0 kB
> HugetlbPages: 0 kB
> Threads: 21
> SigQ: 0/7929
> SigPnd: 0000000000000000
> ShdPnd: 0000000000000000
> SigBlk: fffffffe7bfbbefc
> SigIgn: 0000000000000000
> SigCgt: 0000000180007003
> CapInh: 0000000000000000
> CapPrm: 0000000000000000
> CapEff: 0000000000000000
> CapBnd: 0000003fffffffff
> CapAmb: 0000000000000000
> Seccomp: 0
> Cpus_allowed: f
> Cpus_allowed_list: 0-3
> Mems_allowed: 00000000,00000001
> Mems_allowed_list: 0
> voluntary_ctxt_switches: 260
> nonvoluntary_ctxt_switches: 316
> root@eira:/proc/397#
>
> Config:
>
> server:
> listen: 0.0.0.0@53
> listen: ::@53
> user: knot:knot
>
> log:
> - target: syslog
> any: info
> mod-rrl:
> - id: rrl-10
> rate-limit: 10 # Allow 200 resp/s for each flow
> slip: 2 # Every other response slips
>
> mod-stats:
> - id: custom
> edns-presence: on
> query-type: on
> request-protocol: on
> server-operation: on
> request-bytes: on
> response-bytes: on
> edns-presence: on
> flag-presence: on
> response-code: on
> reply-nodata: on
> query-type: on
> query-size: on
> reply-size: on
>
>
> template:
> - id: default
> storage: "/var/lib/knot"
> module: mod-rrl/rrl-10
> module: mod-stats/custom
> acl: [allowed_transfer]
> disable-any: on
> master: idunn
>
> I was pretty sure that a VM with 2GB RAM is enough for my setup :-)
>
> BR
>
> Ales