Re: [openstack-dev] Re-initializing or dynamically configuring cinder driver
Ah, u might be able to do what u said. Try it out and see how far u can get :) I would be interested to know how u plan on waiting for all existing operations to finish. Maybe it's not so hard, not really sure... Sent from my really tiny device... On Dec 15, 2013, at 9:43 PM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: Ok, I though we can make make cinder-volume aware of SIGTERM call and make sure it terminates with cleaning all the existing operations. If its not possible then probably SIGHUB is the only solution. :( On Mon, Dec 16, 2013 at 10:25 AM, Joshua Harlow harlo...@yahoo-inc.commailto:harlo...@yahoo-inc.com wrote: It depends on the corruption that u are willing to tolerate. Sigterm means the process just terminates, what if said process was 3/4 through some operation (create_volume for example)?? Personally I am willing to tolerate zero corruption, reliability and consistency are foundational things for me. Others may be more tolerant though, seems worth further discussion IMHO. Sent from my really tiny device... On Dec 15, 2013, at 8:39 PM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: How about sending SIGTERM to child processes and then starting them? I know this is the hard way of achieving the objective and SIGHUP approach will handle it more gracefully. As you mentioned it is a major change, tentatively can we use SIGTERM to achieve the objective? On Mon, Dec 16, 2013 at 9:50 AM, Joshua Harlow harlo...@yahoo-inc.commailto:harlo...@yahoo-inc.com wrote: In your proposal does it means that the child process will be restarted (that means kill -9 or sigint??). If so, without taskflow to help (or other solution) that means operations in progress will be corrupted/lost. That seems bad... A SIGHUP approach could be handled more gracefully (but it does require some changes in the underlying codebase to do this refresh). Sent from my really tiny device... On Dec 15, 2013, at 3:11 AM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: I don't know if this is being planned in Icehouse, if not probably proposing an approach will help. We have seen cinder-volume service initialization part. Similarly if we can get our hands on child process that are running under cinder-volume service, if we terminate those process and restart them along with newly added backends. It might help us achieve the target. On Sun, Dec 15, 2013 at 12:49 PM, Joshua Harlow harlo...@yahoo-inc.commailto:harlo...@yahoo-inc.com wrote: I don't currently know of a one size fits all solution here. There was talk at the summit of having the cinder app respond to a SIGHUP signal and attempting to reload config on this signal. Dynamic reloading is tricky business (basically u need to unravel anything holding references to the old config values/affected by the old config values). I would start with a simple trial of this if u want to so it, part if the issue will likely be oslo.config (can that library understand dynamic reloading?) and then cinder drivers themselves (perhaps u need to create a registry of drivers that can dynamically reload on config reloads?). Start out with something simple, isolate the reloading as much as u can to a single area (something like the mentioned registry of objects that can be reloaded when a SIGHUP arrives) and see how it goes. It does seem like a nice feature if u can get it right :-) Sent from my really tiny device... On Dec 13, 2013, at 8:57 PM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: Hi All, At present cinder driver can be only configured with adding entries in conf file. Once these driver related entries are modified or added in conf file, we need to restart cinder-volume service to validate the conf entries and create a child process that runs in background. I am thinking of a way to re-initialize or dynamically configure cinder driver. So that I can accept the configuration from user on fly and perform operations. I think solution lies somewhere around oslo.config.cfg, but I am still unclear about how re-initializing can be achieved. Let know if anyone here is aware of any approach to re-initialize or dynamically configure a driver. -- Thanks, IK ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Thanks, Ibad Khan 9686594607tel:9686594607 ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] Re-initializing or dynamically configuring cinder driver
I don't know if this is being planned in Icehouse, if not probably proposing an approach will help. We have seen cinder-volume service initialization part. Similarly if we can get our hands on child process that are running under cinder-volume service, if we terminate those process and restart them along with newly added backends. It might help us achieve the target. On Sun, Dec 15, 2013 at 12:49 PM, Joshua Harlow harlo...@yahoo-inc.comwrote: I don't currently know of a one size fits all solution here. There was talk at the summit of having the cinder app respond to a SIGHUP signal and attempting to reload config on this signal. Dynamic reloading is tricky business (basically u need to unravel anything holding references to the old config values/affected by the old config values). I would start with a simple trial of this if u want to so it, part if the issue will likely be oslo.config (can that library understand dynamic reloading?) and then cinder drivers themselves (perhaps u need to create a registry of drivers that can dynamically reload on config reloads?). Start out with something simple, isolate the reloading as much as u can to a single area (something like the mentioned registry of objects that can be reloaded when a SIGHUP arrives) and see how it goes. It does seem like a nice feature if u can get it right :-) Sent from my really tiny device... On Dec 13, 2013, at 8:57 PM, iKhan ik.ibadk...@gmail.com wrote: Hi All, At present cinder driver can be only configured with adding entries in conf file. Once these driver related entries are modified or added in conf file, we need to restart cinder-volume service to validate the conf entries and create a child process that runs in background. I am thinking of a way to re-initialize or dynamically configure cinder driver. So that I can accept the configuration from user on fly and perform operations. I think solution lies somewhere around oslo.config.cfg, but I am still unclear about how re-initializing can be achieved. Let know if anyone here is aware of any approach to re-initialize or dynamically configure a driver. -- Thanks, IK ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Thanks, Ibad Khan 9686594607 ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] Re-initializing or dynamically configuring cinder driver
It depends on the corruption that u are willing to tolerate. Sigterm means the process just terminates, what if said process was 3/4 through some operation (create_volume for example)?? Personally I am willing to tolerate zero corruption, reliability and consistency are foundational things for me. Others may be more tolerant though, seems worth further discussion IMHO. Sent from my really tiny device... On Dec 15, 2013, at 8:39 PM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: How about sending SIGTERM to child processes and then starting them? I know this is the hard way of achieving the objective and SIGHUP approach will handle it more gracefully. As you mentioned it is a major change, tentatively can we use SIGTERM to achieve the objective? On Mon, Dec 16, 2013 at 9:50 AM, Joshua Harlow harlo...@yahoo-inc.commailto:harlo...@yahoo-inc.com wrote: In your proposal does it means that the child process will be restarted (that means kill -9 or sigint??). If so, without taskflow to help (or other solution) that means operations in progress will be corrupted/lost. That seems bad... A SIGHUP approach could be handled more gracefully (but it does require some changes in the underlying codebase to do this refresh). Sent from my really tiny device... On Dec 15, 2013, at 3:11 AM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: I don't know if this is being planned in Icehouse, if not probably proposing an approach will help. We have seen cinder-volume service initialization part. Similarly if we can get our hands on child process that are running under cinder-volume service, if we terminate those process and restart them along with newly added backends. It might help us achieve the target. On Sun, Dec 15, 2013 at 12:49 PM, Joshua Harlow harlo...@yahoo-inc.commailto:harlo...@yahoo-inc.com wrote: I don't currently know of a one size fits all solution here. There was talk at the summit of having the cinder app respond to a SIGHUP signal and attempting to reload config on this signal. Dynamic reloading is tricky business (basically u need to unravel anything holding references to the old config values/affected by the old config values). I would start with a simple trial of this if u want to so it, part if the issue will likely be oslo.config (can that library understand dynamic reloading?) and then cinder drivers themselves (perhaps u need to create a registry of drivers that can dynamically reload on config reloads?). Start out with something simple, isolate the reloading as much as u can to a single area (something like the mentioned registry of objects that can be reloaded when a SIGHUP arrives) and see how it goes. It does seem like a nice feature if u can get it right :-) Sent from my really tiny device... On Dec 13, 2013, at 8:57 PM, iKhan ik.ibadk...@gmail.commailto:ik.ibadk...@gmail.com wrote: Hi All, At present cinder driver can be only configured with adding entries in conf file. Once these driver related entries are modified or added in conf file, we need to restart cinder-volume service to validate the conf entries and create a child process that runs in background. I am thinking of a way to re-initialize or dynamically configure cinder driver. So that I can accept the configuration from user on fly and perform operations. I think solution lies somewhere around oslo.config.cfg, but I am still unclear about how re-initializing can be achieved. Let know if anyone here is aware of any approach to re-initialize or dynamically configure a driver. -- Thanks, IK ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Thanks, Ibad Khan 9686594607tel:9686594607 ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Thanks, Ibad Khan 9686594607 ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.orgmailto:OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
