Hi Eoghan, Thanks for the note below. However, one thing the overview below does not cover is why InfluxDB (http://influxdb.com/) is not being leveraged. Many folks feel that this technology is a viable solution for the problem space discussed below.
Thanks, Brad Brad Topol, Ph.D. IBM Distinguished Engineer OpenStack (919) 543-0646 Internet: bto...@us.ibm.com Assistant: Kendra Witherspoon (919) 254-0680 From: Eoghan Glynn <egl...@redhat.com> To: "OpenStack Development Mailing List (not for usage questions)" <email@example.com>, Date: 08/06/2014 11:17 AM Subject: [openstack-dev] [tc][ceilometer] Some background on the gnocchi project Folks, It's come to our attention that some key individuals are not fully up-to-date on gnocchi activities, so it being a good and healthy thing to ensure we're as communicative as possible about our roadmap, I've provided a high-level overview here of our thinking. This is intended as a precursor to further discussion with the TC. Cheers, Eoghan What gnocchi is: =============== Gnocchi is a separate, but related, project spun up on stackforge by Julien Danjou, with the objective of providing efficient storage and retrieval of timeseries-oriented data and resource representations. The goal is to experiment with a potential approach to addressing an architectural misstep made in the very earliest days of ceilometer, specifically the decision to store snapshots of some resource metadata alongside each metric datapoint. The core idea is to move to storing datapoints shorn of metadata, and instead allow the resource-state timeline to be reconstructed more cheaply from much less frequently occurring events (e.g. instance resizes or migrations). What gnocchi isn't: ================== Gnocchi is not a large-scale under-the-radar rewrite of a core OpenStack component along the lines of keystone-lite. The change is concentrated on the final data-storage phase of the ceilometer pipeline, so will have little initial impact on the data-acquiring agents, or on transformation phase. We've been totally open at the Atlanta summit and other forums about this approach being a multi-cycle effort. Why we decided to do it this way: ================================ The intent behind spinning up a separate project on stackforge was to allow the work progress at arms-length from ceilometer, allowing normalcy to be maintained on the core project and a rapid rate of innovation on gnocchi. Note that that the developers primarily contributing to gnocchi represent a cross-section of the core team, and there's a regular feedback loop in the form of a recurring agenda item at the weekly team meeting to avoid the effort becoming silo'd. But isn't re-architecting frowned upon? ====================================== Well, the architecture of other OpenStack projects have also under-gone change as the community understanding of the implications of prior design decisions has evolved. Take for example the move towards nova no-db-compute & the unified-object-model in order to address issues in the nova architecture that made progress towards rolling upgrades unneccessarily difficult. The point, in my understanding, is not to avoid doing the course-correction where it's deemed necessary. Rather, the principle is more that these corrections happen in an open and planned way. The path forward: ================ A subset of the ceilometer community will continue to work on gnocchi in parallel with the ceilometer core over the remainder of the Juno cycle and into the Kilo timeframe. The goal is to have an initial implementation of gnocchi ready for tech preview by the end of Juno, and to have the integration/migration/ co-existence questions addressed in Kilo. Moving the ceilometer core to using gnocchi will be contingent on it demonstrating the required performance characteristics and providing the semantics needed to support a v3 ceilometer API that's fit-for-purpose. _______________________________________________ OpenStack-dev mailing list OpenStackfirstname.lastname@example.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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