ovn-northd服務是集中式方案，集群中所有的ovn-controller服務都連接到ovn-northd，這樣ovn-northd可能會引起單點故障的問題，所以OVN用在生產環境前需要考慮ovn-northd服務HA問題，

這裏記錄的OVN社區ovn-northd服務的HA方案。

Corosync + Pacemaker

corosync +pacemaker使用原理，可參見文檔 http://blog.csdn.net/rzhzhz/article/details/7104135

ovn-northd HA 搭建過程

下面步驟搭建三個節點組成的ovn-northd HA的環境：

系統版本: CentOS7

host: 192.168.10.143 192.168.10.146 192.168.10.147

vip : 192.168.10.200

1.安裝相關組件

 1 # 安裝 corosync,pacemaker
 2 yum install corosynclib corosync
 3 yum install pacemaker-libs pacemaker-cluster-libs pacemaker-cli pacemaker   # 快速安裝 yum install corosync pacemaker -y
 4   
 5 #安裝 crmsh(命令方式管理corosync +pacemaker)
 
 6 yum install crmsh-scripts-3.0.0-2.2.noarch.rpm python-parallax-1.0.1-29.1.noarch.rpm  crmsh-3.0.0-2.2.noarch.rpm
 7   
 8 # 安裝OVN組件
 9 yum install openvswitch
10 yum install openvswitch-ovn-common openvswitch-ovn-central

2. 配置服務(192.168.10.143)

 1 # 配置corosync + pacemaker
 2 ## 編輯 /etc/corosync/corosync.conf
 
 3 totem {
 4         version: 2
 5  
 6         crypto_cipher: aes128
 7         crypto_hash: sha1
 8         secauth: on
 9  
10         interface {
11                 ringnumber: 0
12                 bindnetaddr: 192.168.10.0
13                 mcastaddr: 239.255.1.1
14                 mcastport: 5405
15                 ttl: 1
16         }
17 }
18  
19 nodelist {
20         node {
21                 ring0_addr: 192.168.10.143
22                 nodeid: 1
23         }
24         node {
25                 ring0_addr: 192.168.10.146
26                 nodeid: 2
27         }
28         node {
29                 ring0_addr: 192.168.10.147
30                 nodeid: 3
31         }
32 }
33  
34 logging {
35         fileline: off
36         to_stderr: no
37         to_logfile: yes
38         logfile: /var/log/cluster/corosync.log
39         to_syslog: yes
40         debug: off
41         timestamp: on
42         logger_subsys {
43                 subsys: QUORUM
44                 debug: off
45         }
46 }
47  
48 quorum {
49         provider: corosync_votequorum
50 }
51   
52   
53 # 生成authkey
54 corosync-keygen
55   
56 # 配置ovn-northd服務
57 ##在/etc/openvswitch/目錄創建ovnnb-active.conf  ovnsb-active.conf  ovn-northd-db-params.conf
58 echo ‘tcp:192.168.10.200:6641‘  >  /etc/openvswitch/ovnnb-active.conf
59 echo ‘tcp:192.168.10.200:6642‘  >  /etc/openvswitch/ovnsb-active.conf
60 echo ‘--ovnnb-db=tcp:192.168.10.147:6641 --ovnsb-db=tcp:192.168.10.147:6642‘ > /etc/openvswitch/ovn-northd-db-params.conf
61   
62   
63 # *將上面生成的文件copy到192.168.10.146、192.168.10.147
64   
65 # 啟動各個節上的corosync + pacemaker服務
66 systemctl enable corosync pacemaker
67 systemctl start corosync pacemaker

3. 命令管理corosync + pacemaker

crm_mon查看節點是否加入集群

crm configure 配置方法：

方法1：

 1 #crm configure
 2 property stonith-enabled=false
 3 primitive ovndb_servers ocf:ovn:ovndb-servers params master_ip="192.168.10.200" op start interval="0s" timeout="30s" op stop interval="0s" timeout="20s" op promote interval="0s" timeout="50s" op demote interval="0s" timeout="50s" op monitor interval="10s" timeout="20s"
 4 primitive ovnip ocf:heartbeat:IPaddr2 params ip="192.168.10.200" cidr_netmask="24" op start interval="0s" timeout="20s" op stop interval="0s" timeout="20s" op monitor interval="10s" timeout="20s"
 5 ms ovndb_servers-master ovndb_servers meta notify="true"
 6 colocation colocation-ovndb_servers-master-ovnip-INFINITY inf: ovndb_servers-master:Started ovnip:Master
 7 order order-ovnip-ovndb_servers-master-mandatory inf: ovnip:start ovndb_servers-master:start
 8 verify
 9 commit
10 bye

方法2：

 1 crm configure load repalce /root/ovndb-ha.conf
 2   
 3 # ovndb-ha.conf內容如下：
 4 primitive ovndb_servers ocf:ovn:ovndb-servers params master_ip="192.168.10.200" op start interval="0s" timeout="30s" op stop interval="0s" timeout="20s" op promote interval="0s" timeout="50s" op demote interval="0s" timeout="50s" op monitor interval="10s" timeout="20s"
 5 primitive ovnip ocf:heartbeat:IPaddr2 params ip="192.168.10.200" cidr_netmask="24" op start interval="0s" timeout="20s" op stop interval="0s" timeout="20s" op monitor interval="10s" timeout="20s"
 6 ms ovndb_servers-master ovndb_servers meta notify="true"
 7 colocation colocation-ovndb_servers-master-ovnip-INFINITY inf: ovndb_servers-master:Started ovnip:Master
 8 order order-ovnip-ovndb_servers-master-mandatory inf: ovnip:start ovndb_servers-master:start
 9 property stonith-enabled=false
10 #property no-quorum-policy=ignore

自動加載配置：

1 crm configure save  ./ovndb-ha.conf
2 crm configure load replace ./ovndb-ha.conf
3 crm erase

*註意節點先啟動 openvswitch.service！

crm_mon 顯示各節點的狀態

* 註 ovn-northd service HA：

1 #/usr/lib/ocf/resource.d/ovn/ovndb-servers
2 MANAGE_NORTHD_DEFAULT="yes"

參考文檔：

http://docs.openvswitch.org/en/latest/topics/ovsdb-replication/

http://blog.csdn.net/rzhzhz/article/details/7104135

https://magedu.org/2016/04/23/corosync-pacemaker-mariadb/

https://mail.openvswitch.org/pipermail/ovs-dev/2016-October/324024.html

OVN HA 實驗