Nova Conductor Service: no-db-compute for compute node

Q: 為何要做nova conductor service?這個從folsom版本開始討論構思，一直到了grizzly版本才合併。nova conductor究竟是啥樣子的服務呢!!?

[Dev List]
     Nova Conductor Dev List, http://lists.openstack.org/pipermail/openstack-dev/2012-November/002573.html

A:
主要是不透過Nova DB的存取來降低效能的瓶頸以及compromised compute node會帶來淺在的危險。

 The nova-conductor service is key to completing no-db-compute. Conceptually, it implements a new layer on top of nova-compute.



[Objective]
1. Compute nodes are the least trusted part of a nova deployment, so removing direct database access is a step toward reducing the potential impact of a compromised compute node.

2. The other benefit of no-db-compute is for upgrades. Direct database access complicates the ability to do live rolling upgrades

Reference:

1. http://cloudystuffhappens.blogspot.tw/2013/04/understanding-nova-conductor-in.html
2. http://russellbryantnet.wordpress.com/2013/02/19/deployment-considerations-for-nova-conductor-service-in-openstack-grizzly/