On 27 March 2014 06:28, Eoghan Glynn <egl...@redhat.com> wrote: > > >> On 3/25/2014 1:50 PM, Matt Wagner wrote: >> > This would argue to me that the easiest thing for Ceilometer might be >> > to query us for IPMI stats, if the credential store is pluggable. >> > "Fetch these bare metal statistics" doesn't seem too off-course for >> > Ironic to me. The alternative is that Ceilometer and Ironic would both >> > have to be configured for the same pluggable credential store. >> >> There is already a blueprint with a proposed patch here for Ironic to do >> the querying: >> https://blueprints.launchpad.net/ironic/+spec/send-data-to-ceilometer. > > Yes, so I guess there are two fundamentally different approaches that > could be taken here: > > 1. ironic controls the cadence of IPMI polling, emitting notifications > at whatever frequency it decides, carrying whatever level of > detail/formatting it deems appropriate, which are then consumed by > ceilometer which massages these provided data into usable samples > > 2. ceilometer acquires the IPMI credentials either via ironic or > directly from keystone/barbican, before calling out over IPMI at > whatever cadence it wants and transforming these raw data into > usable samples > > IIUC approach #1 is envisaged by the ironic BP[1]. > > The advantage of approach #2 OTOH is that ceilometer is in the driving > seat as far as cadence is concerned, and the model is far more > consistent with how we currently acquire data from the hypervisor layer > and SNMP daemons.
The downsides of #2 are: - more machines require access to IPMI on the servers (if a given ceilometer is part of the deployed cloud, not part of the minimal deployment infrastructure). This sets of security red flags in some organisations. - multiple machines (ceilometer *and* Ironic) talking to the same IPMI device. IPMI has a limit on sessions, and in fact the controllers are notoriously buggy - having multiple machines talking to one IPMI device is a great way to exceed session limits and cause lockups. These seem fundamental showstoppers to me. -Rob -- Robert Collins <rbtcoll...@hp.com> Distinguished Technologist HP Converged Cloud _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
