Showing posts from December, 2019

Migrating to Nova Cells v2

On 15th October 2019, the Nectar Research Cloud finally migrated to Nova cells v2. This completed a long journey of running multiple patches on nova to make cells v1 work. First a little history..... The Nectar Research Cloud began its journey with cells back in the Essex release. We heard about this new thing called cells (now known as cells v1) and were aware Rackspace were using them in a forked version of Nova. Chris Behrens was the main developer of cells and so I got a conversation going and soon we were running a version of nova from a personal branch from Chris's Github . This helped us scale the Nectar Research Cloud to the scale it is now and was also helpful for our distributed architecture. I think it was Grizzly where cells v1 was merged into the main nova codebase. Finally we were back onto the mainline codebase... however there were multiple things that didn't work, including security groups and aggregates to name a few . That led me down the path of nova de

Understanding telemetry services in Nectar cloud

Intro Openstack telemetry service is to reliably collect data on the utilization of the physical and virtual resources comprising deployed clouds, persist these data for subsequent retrieval and analysis, and trigger actions when defined criteria are met.  Ceilometer project was the only piece of telemetry services in openstack, but since it was dumped into too many functions, it got split into several subprojects: Aodh (alarm evaluation functionality), Panko (events storage) and Ceilometer (data collection - more about ceilometer  history  from ex-PTL). The original storage and API function of ceilometer had been deprecated and moved to the other projects. The latest telemetry architecture could refer to openstack  system architecture . In Nectar cloud, we are using the Ceilometer for the metric data collection, Aodh for the alarm services, Gnocchi for the metric API services, and Influxdb as the time series database backend of Gnocchi. Influxdb backend driver is Nectar impleme