[openstack-dev] [oslo][messaging] messaging vs. messagingv2
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi all, I'm currently pushing Neutron to oslo.messaging, and while at it, a question popped up. So in oslo-rpc, we have the following notification drivers available: neutron.openstack.common.notifier.log_notifier neutron.openstack.common.notifier.no_op_notifier neutron.openstack.common.notifier.rpc_notifier2 neutron.openstack.common.notifier.rpc_notifier neutron.openstack.common.notifier.test_notifier And in oslo.messaging, we have: oslo.messaging.notify._impl_log:LogDriver oslo.messaging.notify._impl_noop:NoOpDriver oslo.messaging.notify._impl_messaging:MessagingV2Driver oslo.messaging.notify._impl_messaging:MessagingDriver oslo.messaging.notify._impl_test:TestDriver My understanding is that they map to each other as in [1]. So atm Neutron uses rpc_notifier from oslo-rpc, so I'm going to replace it with MessagingDriver. So far so good. But then I've checked docstrings for MessagingDriver and MessagingV2Driver [2], and the following looks suspicious to me. For MessagingDriver, it's said: This driver should only be used in cases where there are existing consumers deployed which do not support the 2.0 message format. This sounds like MessagingDriver is somehow obsolete, and we want to use MessagingV2Driver unless forced to. But I don't get what those consumers are. Are these other projects that interact with us via messaging bus? Another weird thing is that it seems that no other project is actually using MessagingV2Driver (at least those that I've checked). Is it even running in wild? Can oslo devs elaborate on that topic? Thanks, /Ihar [1]: https://review.openstack.org/#/c/100013/3/setup.cfg [2]: https://github.com/openstack/oslo.messaging/blob/master/oslo/messaging/notify/_impl_messaging.py -BEGIN PGP SIGNATURE- Version: GnuPG/MacGPG2 v2.0.22 (Darwin) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCgAGBQJTnvDhAAoJEC5aWaUY1u57bCcH/3l05eZZob+ZeNJBuDjmURQi S8p2CCPpMKxXk714Czne9b39+SZaPPH/smyIOObx18aXYcIqKdJzRkB+Ft/ObLB/ 2/dc/Vi7vzAIY3at11yXc2g+o0Ix1SmHBz3Jhh4V0x+Zp6U950ZsG75Jm+Mp2E/v YK6Qy2snSpe2irdkNoTjz+DEK6kSZZvuOE9mLjGttTyMLhk+dWPlPITXu1MZfam1 9b32O22gf06KOePGHu15W7eVJu9M6Z4EyFMAQsZFcc4IgQV4r2hXM2R/x7ER/SHC Xsug33LJnsu2yWbS1zxSXr9sUVs7ZtDEdmvLUg30BLfOxEICD1L3ygj2uPhsupY= =NSoq -END PGP SIGNATURE- ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [oslo][messaging] messaging vs. messagingv2
Hi Ihar, On Mon, 2014-06-16 at 15:28 +0200, Ihar Hrachyshka wrote: Hi all, I'm currently pushing Neutron to oslo.messaging, and while at it, a question popped up. So in oslo-rpc, we have the following notification drivers available: neutron.openstack.common.notifier.log_notifier neutron.openstack.common.notifier.no_op_notifier neutron.openstack.common.notifier.rpc_notifier2 neutron.openstack.common.notifier.rpc_notifier neutron.openstack.common.notifier.test_notifier And in oslo.messaging, we have: oslo.messaging.notify._impl_log:LogDriver oslo.messaging.notify._impl_noop:NoOpDriver oslo.messaging.notify._impl_messaging:MessagingV2Driver oslo.messaging.notify._impl_messaging:MessagingDriver oslo.messaging.notify._impl_test:TestDriver My understanding is that they map to each other as in [1]. So atm Neutron uses rpc_notifier from oslo-rpc, so I'm going to replace it with MessagingDriver. So far so good. So far so good, indeed. But then I've checked docstrings for MessagingDriver and MessagingV2Driver [2], and the following looks suspicious to me. For MessagingDriver, it's said: This driver should only be used in cases where there are existing consumers deployed which do not support the 2.0 message format. This sounds like MessagingDriver is somehow obsolete, and we want to use MessagingV2Driver unless forced to. But I don't get what those consumers are. Are these other projects that interact with us via messaging bus? Another weird thing is that it seems that no other project is actually using MessagingV2Driver (at least those that I've checked). Is it even running in wild? The idea is that deployments should move over to the v2 on-the-wire format, but we've never made any great efforts for that to happen. Part of the issue here is that notifications are consumed by codebases outside of OpenStack and, so, changing the default to v2 would likely unnecessarily disrupt some people. The reason no-one has pushed very hard on a firm deprecation plan for the v1 format is that the v2 format doesn't yet offer a huge amount of advantages. Right now it just adds a '2.0' version number to the format. When we gain the ability to sign notification messages, this will only be available via the v2 format and that will encourage more focus on switching over fully. Mark. ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
