<p dir="ltr">Going from memory of the code I believe this is possible. Iirc the lock is a select for update so assuming innodb it will prevent two workers from assigning the same network to multiple tenants but won't prevent two networks being assigned to the same tenant. This is probably an untested consequence of clan plus multi host. A decent workaround would be to assign a network to a tenant immediately after creation instead of lazily.</p>
<div class="gmail_quote">On Feb 5, 2013 12:56 PM, "rezroo" <<a href="mailto:reza@dslextreme.com">reza@dslextreme.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
I've run into this issue and I'd like to get some opinions before
logging a defect. I'm using folsom, deployed using VlanManager. It
seems to me that the assignment of a network to a tenant is lazy
evaluated until the first instance for the project is launched.
This can be confirmed by creating a new tenant and then doing
'nova-manage network list'. If one now launches multiple tenants by
setting the number of instances to 4 or 5 then there is a race
condition and it is possible that two or more vlan/networks are
assigned to the tenant. I'm running into this issue.<br>
<br>
I posted to Openstack-operators already and I got one reply back
claiming that this is a configuration issue, without any insight as
to what is misconfigured. Do you know what kind of misconfiguration
leads to this? Or what concurrency/locking mechanism prevents this
from happening? Presumably a select is done in the networks table
to see if a vlan is already assigned to a tenant. If you have
sufficiently fast environment it is possible that two simultaneous
queries are done, both with no results, and two networks are
assigned and committed to the database. This is what happened for
me. What misconfiguration should I look for, or what
concurrency/locking mechanism is there to prevent this?
<div><br>
Or I can log a defect.<br>
<br>
Thanks,<br>
Rez<br>
<br>
-------- Original Message --------
<table border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<th nowrap valign="BASELINE" align="RIGHT">Subject:
</th>
<td>Re: [Openstack-operators] Simultaneous launch of
multiple instances from horizon leads to multiple LANs
assigned to new tenant</td>
</tr>
<tr>
<th nowrap valign="BASELINE" align="RIGHT">Date: </th>
<td>Tue, 05 Feb 2013 05:41:37 -0800</td>
</tr>
<tr>
<th nowrap valign="BASELINE" align="RIGHT">From: </th>
<td>rezroo <a href="mailto:reza@dslextreme.com" target="_blank"><reza@dslextreme.com></a></td>
</tr>
<tr>
<th nowrap valign="BASELINE" align="RIGHT">To: </th>
<td>Vivek Singh Raghuwanshi
<a href="mailto:vivekraghuwanshi@gmail.com" target="_blank"><vivekraghuwanshi@gmail.com></a></td>
</tr>
</tbody>
</table>
<br>
<br>
<div>Still using nova-network due to its
better integration with Horizon.<br>
Do you know what kind of misconfiguration leads to this? Or what
concurrency/locking mechanism prevents this from happening? So
presumably a select is done in the networks table to see if a
vlan is already assigned to a tenant. If you have sufficiently
fast environment it is possible that two simultaneous queries
are done, both with no results, and two networks are assigned
and committed to the database. This is what happened for me.
What misconfiguration should I look for, or what
concurrency/locking mechanism is there to prevent this?<br>
Thanks,<br>
Rez<br>
<br>
On 02/04/2013 11:03 PM, Vivek Singh Raghuwanshi wrote:<br>
</div>
<blockquote type="cite">This only happens due to misconfiguration, but are
you still with nova-network.<br>
its advisable to switch your cloud with Quantum<br>
<br>
<div class="gmail_quote">On Tue, Feb 5, 2013 at 5:05 AM, rezroo
<span dir="ltr"><<a href="mailto:reza@dslextreme.com" target="_blank">reza@dslextreme.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi - I'm
wondering if others have seen this defect and if it has
already been reported or not.<br>
I'm using folsom, deployed using VlanManager.<br>
When a new tenant is created no vlan/network is assigned to
it until the first instance for the project is launched.
This can be confirmed by creating a new tenant and then
doing 'nova-manage network list'.<br>
If now one launches multiple tenants by setting the number
of instances to 4 or 5 then there is a race condition and it
is possible that two or more vlan/networks are assigned to
the tenant.<br>
Should I log this as a defect?<br>
Thanks,<br>
Rez<br>
<br>
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<br>
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