[Openstack] [OpenStack][Nova]Problems and questions regarding network and/or routing

Leander Bessa Beernaert leanderbb at gmail.com
Wed Sep 5 13:49:27 UTC 2012


I'm having the strangest issue. I have set up a separate OpenStack cluster
to test out the multi-host setup.

I have one controller node and 4 compute nodes. Each compute node is
running nova-network, nova-compute and nova-api-metadata. I have set up a
tenant with the a multi-host network on the address range 10.0.108.0/24.

I launched 4 instances to fill up the compute nodes:

+--------------------------------------+------+--------+----------------------------+
|                  ID                  | Name | Status |          Networks
         |
+--------------------------------------+------+--------+----------------------------+
| 2c63cc3e-7c45-4e10-8ac5-480fa60d4f32 | Test | ACTIVE |
project_network=10.0.108.7 |
| c48f6aae-0d97-4e69-a398-8cda929c310d | Test | ACTIVE |
project_network=10.0.108.3 |
| ed8f11a4-5fc0-4437-9ae2-b6725126fca7 | Test | ACTIVE |
project_network=10.0.108.5 |
| fe39e586-030c-4bf4-9020-7ef773567913 | Test | ACTIVE |
project_network=10.0.108.9 |
+--------------------------------------+------+--------+----------------------------+

One thing i found odd at the beginning was the fact that the instances are
using only odd addresses. The installation is clean and no instances have
been launched before, so all the addresses are available.

The problem now is that i can only ping instances form the compute nodes. I
am unable to ping any instance from the controller node. Stranger yet, is
the fact that i can ping non-existent address such as
10.0.108.4,10.0.108.6,10.0.108.8 and 10.0.108.4.10.
I have also no connectivity from within the instances to the outside world.

Has this happend to anyone before?


On Tue, Sep 4, 2012 at 11:38 PM, Vishvananda Ishaya
<vishvananda at gmail.com>wrote:

>
> On Sep 4, 2012, at 3:01 PM, Leander Bessa Beernaert <leanderbb at gmail.com>
> wrote:
>
> Question follows inlined below.
>
> On Tue, Sep 4, 2012 at 6:48 PM, Vishvananda Ishaya <vishvananda at gmail.com>wrote:
>
>>
>> On Sep 4, 2012, at 8:35 AM, Leander Bessa Beernaert <leanderbb at gmail.com>
>> wrote:
>>
>> Hello all,
>>
>> I've had a few reports from users testing out the sample installation of
>> OpenStack  i setup. The reports were all related to problems with inter-vm
>> network speeds and connection timeouts as well as the inability to connect
>> to the outside word from within the VM (e.g.: ping www.google.com). I'm
>> not sure if i setup something wrong, so i have a few questions.
>>
>> The current installation of OpenStack is running with 1 controller node,
>> and 8 compute nodes. Each node is running Ubuntu 12.04 and Essex with the
>> default packages. I'm using the VLAN network manager. There is one
>> peculiarity to this setup. Since each physical hosts only has 1 network
>> interface,  i came up with the following configuration:
>>   - For inter-node communications i set up  a VLAN with the ID 107
>>   - Each tentant has it's private network on a separate VLAN. Currently
>> there are two tenant, one on VLAN 109 (network: 10.0.9.0/24) and another
>> on VLAN 110 (network: 10.0.9.0/24).
>>
>> I'm not a network expert, so please bear with me if i make any outrages
>> statements.
>>
>> 1) When communicating on the private network, the packets are not routed
>> through the controller right? That only happens when the VM needs to
>> contact an external source (e.g.: google), correct? This report originated
>> from users from VLAN 109. They are using network intensive applications
>> which send a lot of data between each of the instances. They reported
>> various time-out and connection drops as well as slow transfer speeds. I'm
>> no network expert, but could this be related to the routing, VLANs or is it
>> a hardware issue?
>>
>>
>> There are a lot of things that could cause this. You would need to do
>> some extensive debugging to find the source of this.
>>
>
> Any ideas where i can start looking?
> Also, communications between two VMs on different compute nodes from the
> same tenant do not need to be routed through the controller node right?
>
>
> in non-multi_host mode I believe it will go through the controller.
>
> Vish
>
>


-- 
Cumprimentos / Regards,
Leander
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