designate/doc/source/admin/ha.rst

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 = True

Or the following:

[oslo_middleware]
enable_proxy_headers_parsing = true

And 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.