Hello,

My test consists in starting small containers (10MB of RAM ) each. Each
container has 2x physical VLAN interfaces attached.

lxc.network.type = phys
lxc.network.flags = up
lxc.network.link = eth6.3
lxc.network.name = eth2
lxc.network.hwaddr = 00:50:56:a8:03:03
lxc.network.ipv4 = 192.168.1.1/24
lxc.network.type = phys
lxc.network.flags = up
lxc.network.link = eth7.3
lxc.network.name = eth1
lxc.network.ipv4 = 2.2.2.2/24
lxc.network.hwaddr = 00:50:57:b8:00:01



With initial iproute2 , when I reach around 1600 containers, container
creation almost stops.It takes at least 20s per container to start.
With patched iproutes2 , I have started 4000 containers at a rate of 1 per
second w/o problem. I have 8000 clan interfaces configured on the host (2x
4000).


Regards

Benoit

On 28/03/2013 14:36, "Serge Hallyn" [off-list ref] wrote:

Quoting Eric W. Biederman (ebiederm@xmission.com):

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Serge Hallyn [off-list ref] writes:

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Quoting Eric W. Biederman (ebiederm@xmission.com):

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Serge Hallyn [off-list ref] writes:

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Quoting Eric W. Biederman (ebiederm@xmission.com):

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Stephen Hemminger [off-list ref] writes:

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If you need to do lots of operations the --batch mode will be

significantly faster.

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One command start and one link map.

The problem in this case as I understand it is lots of independent
operations. Now maybe lxc should not shell out to ip and perform

the

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work itself.

fwiw lxc uses netlink to create new veths, and picks random names

with

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mktemp() ahead of time.

I am puzzled where does the slownes in iproute2 come into play?

Benoit originally reported slowness when starting >1500 containers.  I
asked him to run a few manual tests to figure out what was taking the
time.  Manually creating a large # of veths was an obvious test, and
one which showed poorly scaling performance.

Apparently iproute is involved somehwere as when he tested with a
patched iproute (as you asked him to) the lxc startup slowdown was
gone.

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May well be there are other things slowing down lxc of course.

The evidence indicates it was iproute being called somewhere...

Benoit can you tell us exactly what test you were running when you saw
the slowdown was gone?

-serge