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<p><font size="2" face="sans-serif">Well, for my specific error, it was an intermittent ssl handshake error before the request was ever sent to the</font><br>
<font size="2" face="sans-serif">neutron-server. In our case, we saw that 4 out of 5 resize operations worked, the fifth failed with this ssl</font><br>
<font size="2" face="sans-serif">handshake error in neutronclient.</font><br>
<br>
<font size="2" face="sans-serif">I certainly think a GET is safe to retry, and I agree with your statement that PUTs and DELETEs probably</font><br>
<font size="2" face="sans-serif">are as well. This still leaves a change in nova needing to be made to actually a) specify a conf option and</font><br>
<font size="2" face="sans-serif">b) pass it to neutronclient where appropriate.<br>
</font><br>
<br>
<tt><font size="2">Aaron Rosen <aaronorosen@gmail.com> wrote on 05/28/2014 07:38:56 PM:<br>
<br>
> From: Aaron Rosen <aaronorosen@gmail.com></font></tt><br>
<tt><font size="2">> To: "OpenStack Development Mailing List (not for usage questions)" <br>
> <openstack-dev@lists.openstack.org>, </font></tt><br>
<tt><font size="2">> Date: 05/28/2014 07:44 PM</font></tt><br>
<tt><font size="2">> Subject: Re: [openstack-dev] [neutron] Supporting retries in neutronclient</font></tt><br>
<tt><font size="2">> <br>
> Hi, </font></tt><br>
<tt><font size="2">> <br>
> I'm curious if other openstack clients implement this type of retry <br>
> thing. I think retrying on GET/DELETES/PUT's should probably be okay. </font></tt><br>
<tt><font size="2">> <br>
> What types of errors do you see in the neutron-server when it fails <br>
> to respond? I think it would be better to move the retry logic into <br>
> the server around the failures rather than the client (or better yet<br>
> if we fixed the server :)). Most of the times I've seen this type of<br>
> failure is due to deadlock errors caused between (sqlalchemy and <br>
> eventlet *i think*) which cause the client to eventually timeout. </font></tt><br>
<tt><font size="2">> <br>
> Best, </font></tt><br>
<tt><font size="2">> <br>
> Aaron</font></tt><br>
<tt><font size="2">> <br>
</font></tt><br>
<tt><font size="2">> On Wed, May 28, 2014 at 11:51 AM, Paul Ward <wpward@us.ibm.com> wrote:</font></tt><br>
<tt><font size="2">> Would it be feasible to make the retry logic only apply to read-only<br>
> operations? This would still require a nova change to specify the <br>
> number of retries, but it'd also prevent invokers from shooting <br>
> themselves in the foot if they call for a write operation.<br>
> <br>
> <br>
> <br>
> Aaron Rosen <aaronorosen@gmail.com> wrote on 05/27/2014 09:40:00 PM:<br>
> <br>
> > From: Aaron Rosen <aaronorosen@gmail.com></font></tt><br>
<tt><font size="2">> <br>
> > To: "OpenStack Development Mailing List (not for usage questions)" <br>
> > <openstack-dev@lists.openstack.org>, </font></tt><br>
<tt><font size="2">> > Date: 05/27/2014 09:44 PM</font></tt><br>
<tt><font size="2">> <br>
> > Subject: Re: [openstack-dev] [neutron] Supporting retries in neutronclient</font></tt><br>
<tt><font size="2">> > <br>
> > Hi, </font></tt><br>
<tt><font size="2">> <br>
> > <br>
> > Is it possible to detect when the ssl handshaking error occurs on <br>
> > the client side (and only retry for that)? If so I think we should <br>
> > do that rather than retrying multiple times. The danger here is <br>
> > mostly for POST operations (as Eugene pointed out) where it's <br>
> > possible for the response to not make it back to the client and for <br>
> > the operation to actually succeed. <br>
> > <br>
> > Having this retry logic nested in the client also prevents things <br>
> > like nova from handling these types of failures individually since <br>
> > this retry logic is happening inside of the client. I think it would<br>
> > be better not to have this internal mechanism in the client and <br>
> > instead make the user of the client implement retry so they are <br>
> > aware of failures. <br>
> > <br>
> > Aaron <br>
> > <br>
> <br>
> > On Tue, May 27, 2014 at 10:48 AM, Paul Ward <wpward@us.ibm.com> wrote:<br>
> > Currently, neutronclient is hardcoded to only try a request once in <br>
> > retry_request by virtue of the fact that it uses self.retries as the<br>
> > retry count, and that's initialized to 0 and never changed. We've <br>
> > seen an issue where we get an ssl handshaking error intermittently <br>
> > (seems like more of an ssl bug) and a retry would probably have <br>
> > worked. Yet, since neutronclient only tries once and gives up, it <br>
> > fails the entire operation. Here is the code in question:<br>
> > <br>
> > <a href="https://github.com/openstack/python-neutronclient/blob/master/">https://github.com/openstack/python-neutronclient/blob/master/</a><br>
> > neutronclient/v2_0/client.py#L1296<br>
> > <br>
> > Does anybody know if there's some explicit reason we don't currently<br>
> > allow configuring the number of retries? If not, I'm inclined to <br>
> > propose a change for just that.<br>
> > <br>
> > _______________________________________________<br>
> > OpenStack-dev mailing list<br>
> > OpenStack-dev@lists.openstack.org<br>
> > <a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev</a><br>
> <br>
> > _______________________________________________<br>
> > OpenStack-dev mailing list<br>
> > OpenStack-dev@lists.openstack.org<br>
> > <a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev</a></font></tt><br>
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