High Availability Guide
Designate supports running all of its components services in
“active-active” HA modes.
Some services require some extra setup to ensure that they can work
in active-active, and the services are listed below.
designate-api
Needs Access to:
- AMQP
blockdiag {
loadbalancer [label=”L7 Load Balancer”, stacked]; amqp_servers
[label=”AMQP Servers”, stacked] group api_servers { label = “API
Servers”; api_server_1 [label=”API Server 1″]; api_server_2 [label=”API
Server 2″]; api_server_3 [label=”API Server 3″]; } loadbalancer ->
api_server_1, api_server_2, api_server_3; api_server_1, api_server_2,
api_server_3 -> amqp_servers;
}
Notes
To run multiple designate-api
services, you should run the services behind a load balancer.
When behind the load balancer, you may need to set the following:
[service:api]
api_base_uri = http://<load balancer URI>/
enable_host_header = TrueOr the following:
[oslo_middleware]
enable_proxy_headers_parsing = trueAnd then the load balancer to set appropriate headers (e.g. enable
mod_proxy in apache.)
designate-central
Needs Access to:
- AMQP
- Database
blockdiag {
amqp_servers [label=”AMQP Servers”, stacked] db_servers
[label=”Database Servers”, stacked, shape=flowchart.database] group
designate_central_servers { label = “designate-central Servers”;
designate_central_server_1 [label=”designate-central Server 1″,
width=256]; designate_central_server_2 [label=”designate-central Server
2″, width=256]; designate_central_server_3 [label=”designate-central
Server 3″, width=256]; } amqp_servers <->
designate_central_server_1, designate_central_server_2,
designate_central_server_3; designate_central_server_1,
designate_central_server_2, designate_central_server_3 ->
db_servers;
}
Notes
You can run as many designate-central
services as needed, as long as they all have access to the AMQP
server(s), work will be distributed across all of them.
designate-mdns
Needs Access to:
- AMQP
- Database
- DNS Servers
blockdiag {
amqp_servers [label=”AMQP Servers”, stacked] dns_servers [label=”DNS
Servers”, stacked, shape=”cloud”] db_servers [label=”Database Servers”,
stacked, shape=flowchart.database] group designate_mdns_servers { label
= “designate-mdns Servers”; designate_mdns_server_1
[label=”designate-mdns Server 1″, width=256]; designate_mdns_server_2
[label=”designate-mdns Server 2″, width=256]; designate_mdns_server_3
[label=”designate-mdns Server 3″, width=256]; } amqp_servers <->
designate_mdns_server_1, designate_mdns_server_2,
designate_mdns_server_3; designate_mdns_server_1,
designate_mdns_server_2, designate_mdns_server_3 <- db_servers;
designate_mdns_server_1, designate_mdns_server_2,
designate_mdns_server_3 -> dns_servers;
}
Notes
You can run as many designate-mdns
services as needed, as long as they all have access to the AMQP
server(s), work will be distributed across all of them.
designate-worker
Needs Access to:
- AMQP
- DNS Servers
blockdiag {
amqp_servers [label=”AMQP Servers”, stacked] dns_servers [label=”DNS
Servers”, stacked, shape=”cloud”] group designate_worker_servers { label
= “designate-worker Servers”; designate_worker_server_1
[label=”designate-worker Server 1″, width=256];
designate_worker_server_2 [label=”designate-worker Server 2″,
width=256]; designate_worker_server_3 [label=”designate-worker Server
3″, width=256]; } amqp_servers <-> designate_worker_server_1,
designate_worker_server_2, designate_worker_server_3;
designate_worker_server_1, designate_worker_server_2,
designate_worker_server_3 -> dns_servers;
}
Notes
You can run as many designate-worker
services as needed, as long as they all have access to the AMQP
server(s), work will be distributed across all of them.
designate-producer
Needs Access to:
- AMQP
- DLM
blockdiag {
amqp_servers [label=”AMQP Servers”, stacked] dlm_servers [label=”DLM
Servers”, stacked] group designate_producer_servers { label =
“designate-producer Servers”; designate_producer_server_1
[label=”designate-producer Server 1″, width=256];
designate_producer_server_2 [label=”designate-producer Server 2″,
width=256]; designate_producer_server_3 [label=”designate-producer
Server 3″, width=256]; } amqp_servers <->
designate_producer_server_1, designate_producer_server_2,
designate_producer_server_3; designate_producer_server_1,
designate_producer_server_2, designate_producer_server_3 ->
dlm_servers;
}
Notes
You can run as many designate-producer
services as needed, as long as they all have access to the AMQP
server(s), and a distributed lock manager, work will be sharded across
all the services.
You will need to set a coordination backend_url. This needs to be a DLM that is
supported by tooz, that supports group membership. See tooz
driver list for available drivers
Warning
Failure to set a backend_url can cause
unexpected consequences, and may result in some periodic tasks being ran
more than once.
[coordination]
backend_url = kazoo://<zookeeper url>:<zookeeper port>designate-sink
Needs Access to:
- AMQP
blockdiag {
amqp_servers [label=”AMQP Servers”, stacked] group
designate_sink_servers { label = “designate-sink Servers”;
designate_sink_server_1 [label=”designate-sink Server 1″, width=256];
designate_sink_server_2 [label=”designate-sink Server 2″, width=256];
designate_sink_server_3 [label=”designate-sink Server 3″, width=256]; }
amqp_servers <-> designate_sink_server_1, designate_sink_server_2,
designate_sink_server_3;
}
Notes
You can run as many designate-sink
services as needed, as long as they all have access to the AMQP
server(s), work will be distributed across all of them.