Hello

I think I found my answer here: https://www.ovn.org/support/dist-docs/ovn-ctl.8.html

There are commands for running ovsdb-server and ovn-northd in HA cluster mode

However, theres no mention of external setup like pacemaker

This page(https://docs.openvswitch.org/en/latest/ref/ovsdb.7/) says ovsdb achieves HA through raft algorithm

Do ovsdb-server and ovn-northd use raft like etcd, so don't require external intervention like pacemaker?

Thank you

---------- 원본 메일 ----------
보낸사람: "박경원" <park0kyung0won@dgist.ac.kr>
받는사람: openstack-discuss@lists.openstack.org
날짜: 2022-08-29 (월) 18:14:27
제목: Openstack OVN (Open Virtual Network) HA deployment - running OVN in active/passive mode?

Hello

I'm trying to deploy openstack with OVN and HA feature

I have two questions about deploying OVN in HA mode, in controller node

I want to have highly available OVN services in controller nodes, placing them(OVN services) behind HAProxy

Currently I'm using Ubuntu 22.04 + Openstack Yoga version

I'm following this guide: https://docs.openstack.org/networking-ovn/latest/install/manual.html

Q1. How can I run ovsdb-server and ovn-northd  in active/passive manner?

Seems like controller node should run ovsdb-server and ovn-northd,

but they are stateful, must be run in some kind of cluster mode like mysql/galera cluster

Let's say I have three controller nodes: node0, node1, node2

I started ovsdb-server and ovn-northd on node0, perhaps in active mode by default

then I want to start ovsdb-server and ovn-northd on node1 and node2 as well, but must be in passive mode, following ovsdb-server and ovn-northd of node0

How can I make them(services on node1 and node2) start in passive mode?

Q2. Where can I get pacemaker script for ovsdb-server and ovn-northd ?

When node0 goes down, pacemaker would detect that node0 is dead, then promote services(ovsdb-server, ovn-northd) on either node1 or node2 to active mode

In order to do that, seems like I need pacemaker resource script: ocf:ovsdb-server.ocf and ocf:ovndb-servers.ocf

Where can I get them and how can I add those to my pacemaker?

I can't find them on my ubuntu 22.04 machine when I type "pcs resource list"

Thank you in advance!