Openstack 高可靠部署方案

根据服务自身状况，HA 分为 Active/Active 和 Active/Passive 两种

Active/Active:   适合于 stateless/stateful 服务，常用 load balance + keepalive(VIP) 配置 HA

Active/Passive: 适用于 stateful 服务，常用 load balance + keepalive(VIP) + pacemaker + Corosync 配置 HA

Openstack HA 实现

Database(Active/Active):

官方推荐：MySQL with Galera

http://docs.openstack.org/high-availability-guide/content/ha-aa-db.html

AMQP(Active/Active):

官方推荐：RabbitMQ cluster

https://openstack.redhat.com/RabbitMQ

Openstack API(Active/Active):

keystone, glance-api, glance-registry, neutron-server, ceilometer-api, dashboard。

均为 stateless 服务，通过 Load balance + keepalive 保证 HA，部署于 Apache server 可提高性能，Haproxy(1.5.0)支持 SSL。

Loadbalance for openstack api

http://openstack.redhat.com/Load_Balance_OpenStack_API

Configuration SSL for haproxy

http://www.b2btech.in/implement-ssl-termination-haproxy-ubuntu-14-04

Runs openstack api in apache

http://andy.mc.it/2013/07/apache2-mod_wsgi-openstack-pt-2-nova-api-os-compute-nova-api-ec2/#comment-35

Openstack scheduler(Active/Active):

nova-scheduler, nova-conductor, nova-consoleauth, nova-novncproxy, ceilometer-collector, cinder-scheduler。

均为 stateless 服务，恰当的配置与 AMQP server 连接参数即可

http://docs.openstack.org/high-availability-guide/content/_run_openstack_api_and_schedulers.html

 Memcached(Active/Active):

1. 提高 Dashboard 的性能

2. 解决 nova-consoleauth 单点问题

https://code.google.com/p/memcached/wiki/NewStart

Network:

1.  neutron DHCP agent(Active/Passive)

2.  neutron L3 agent(Active/Passive)

3.  neutron metadata agent(Active/Passive)

以上三者均由 Pacemaker + Corosync 配置

http://docs.openstack.org/high-availability-guide/content/ch-network.html

Storage:

ceph 保证 image storage, volume storage, nova backend 可靠性

http://www.ceph.com/docs/next/rbd/rbd-openstack/