ovn架構(gòu)
參考: https://www.ovn.org/support/dist-docs/ovn-architecture.7.html



                                         CMS                  ----  neutron|kube-ovn-controller
                                          |
                                          |
                              +-----------|-----------+
                              |           |           |
                              |     OVN/CMS Plugin    |
                              |           |           |
                              |           |           |       
                              |   OVN Northbound DB   |
                              |           |           |
                              |           |           |
                              |       ovn-northd      |
                              |           |           |
                              +-----------|-----------+
                                          |
                                          |
                                +-------------------+
                                | OVN Southbound DB |
                                +-------------------+
                                          |
                                          |
                       +------------------+------------------+
                       |                  |                  |
         HV 1          |                  |    HV n          |
       +---------------|---------------+  .  +---------------|---------------+
       |               |               |  .  |               |               |
       |        ovn-controller         |  .  |        ovn-controller         |
       |         |          |          |  .  |         |          |          |
       |         |          |          |     |         |          |          |
       |  ovs-vswitchd   ovsdb-server  |     |  ovs-vswitchd   ovsdb-server  |
       |                               |     |                               |
       +-------------------------------+     +-------------------------------+






# 1. 整理kube-ovn的服務(wù)并與上述拓?fù)鋵?duì)應(yīng)

1. kube-ovn-controller     k8s cni 網(wǎng)絡(luò)crd 控制平面:網(wǎng)絡(luò) crd 控制器，ipam，單點(diǎn)運(yùn)行摹量，主備模式，k8s leader選舉
2. ovn-central       ovn-網(wǎng)絡(luò)控制平面           接受邏輯流表尺栖，存入nb-db，經(jīng)ovn-northd將邏輯流表轉(zhuǎn)化為物理流表，存入ovn-sb-db
包含： 
ovn-nb-db  raft 選舉，全量快照同步晕城，磁盤最好上ssd
ovn-northd
ovn-sb-db  raft 選舉，全量快照同步窖贤，磁盤最好上ssd

另一個(gè)方案广辰，目前同步功能雖然存在暇矫，但是受網(wǎng)絡(luò)波動(dòng)主之，磁盤性能等異性相择吊，以及全量快照同步的方式影響，單節(jié)點(diǎn)維護(hù)也是一個(gè)非巢坜龋靠譜的方案几睛。
類似neutron， kube-ovn也有從數(shù)據(jù)庫(kù)（etcd）恢復(fù)網(wǎng)絡(luò)控制平面數(shù)據(jù)的方案粤攒。 
當(dāng)然這種方案可能恢復(fù)的時(shí)間慢點(diǎn)所森，適合私有云場(chǎng)景。 
公有云大集群還是需要深入底層提供快照增量同步的方式夯接，提高同步效率

ovn-northd 承上啟下  上承 nb-db焕济，下接 sb-db
這三個(gè)組件確實(shí)是ovn 控制平面的核心，所以命名central
3. ovs-ovn   ovn 網(wǎng)絡(luò)轉(zhuǎn)發(fā)平面
ovn-controller  從sb-db 同步物理流表
ovs-vswitchd    軟件交換機(jī)
ovsdb-server    面向流表的持久化數(shù)據(jù)庫(kù)盔几，物理機(jī)重啟后晴弃，可直接恢復(fù)網(wǎng)絡(luò)功能

## 位于每一個(gè)節(jié)點(diǎn)


4. kube-ovn-cni
該組件用于下發(fā)kube-ovn cni
同時(shí)為kube-ovn cni提供ipam功能，有部分qos邏輯好像在這里面實(shí)現(xiàn)



其實(shí)ovn-controller有兩種角色逊拍，一種是只負(fù)責(zé)大二層的上鞠，另一種還提供公網(wǎng)網(wǎng)關(guān)snat功能的，在neutron里面前者就是ovn-controller芯丧，后者叫做ovn-gw-controller
其實(shí)主要在于ovn-controller對(duì)應(yīng)的chassis是否加入到ha chassis group芍阎，綁定到lrp。



# 2. 整理neutron-ovn的服務(wù)并與上述拓?fù)鋵?duì)應(yīng)



# 集群ovn agent 

# 控制（網(wǎng)絡(luò)）節(jié)點(diǎn)

(py3env) [root@control01 ~]# neutron agent-list | grep -v compute
+--------------------------------------+------------------------------+------------+-------------------+-------+----------------+----------------------------+
| id                                   | agent_type                   | host       | availability_zone | alive | admin_state_up | binary                     |
+--------------------------------------+------------------------------+------------+-------------------+-------+----------------+----------------------------+
| control02                            | OVN Controller Gateway agent | control02  |                   | :-)   | True           | ovn-controller             |
| 76f8382f-8af1-4eb7-85da-82f05952013a | OVN Metadata agent           | control02  |                   | :-)   | True           | neutron-ovn-metadata-agent |
+--------------------------------------+------------------------------+------------+-------------------+-------+----------------+----------------------------+

(py3env) [root@control01 ~]# neutron agent-list | grep  compute010
+--------------------------------------+------------------------------+------------+-------------------+-------+----------------+----------------------------+
| compute010                           | OVN Controller agent         | compute010 |                   | :-)   | True           | ovn-controller             |
| 190b3f77-8111-48f5-a25f-0ee19fa7a3f8 | OVN Metadata agent           | compute010 |                   | :-)   | True           | neutron-ovn-metadata-agent |
+--------------------------------------+------------------------------+------------+-------------------+-------+----------------+----------------------------+


# controller01
neutron_server

# control02
neutron_server
neutron_ovn_metadata_agent

ovn_northd
ovn_sb_db
ovn_nb_db

ovn_controller  # ovn gw 節(jié)點(diǎn)缨恒，負(fù)責(zé)網(wǎng)關(guān)
openvswitch_vswitchd
openvswitch_db

# compute
neutron_ovn_metadata_agent

ovn_controller # 僅負(fù)責(zé)大二層
openvswitch_vswitchd
openvswitch_db