Hi, 3 nodes requirements come from MySQL galera and RabbitMQ clustering because of quorum requirements ( it should be in odd numbers 1, 3, 5 etc..). Rest of components works without clustering and they live behind HAProxy LB for load sharing and redundancy. Someone else can add more details here if I missed something. On Thu, Aug 25, 2022 at 4:05 AM 박경원 <park0kyung0won@dgist.ac.kr> wrote:
Hello
I have two questions about deploying openstack in high available setup
Specifically, HA setup for controller nodes
1. Are openstack services (being deployed on controller nodes) stateless?
Aside from non-openstack packages(galera/mysql, zeromq, ...) for infrastructure, are openstack services stateless?
For example, can I achieve high availability by deploying two nova-api services to two separate controller nodes
by load balacing API calls to them through HAproxy?
Is this(load balancer) the way how openstack achieves high availability?
2. Why minimum 3 controller nodes for HA?
Is this solely due to etcd?
Thanks!