Create an origin pool

An origin pool groups the servers that can answer for a hostname, such as the web servers in one data centre, with a health check on each. Create one pool per group of servers, then a load balancer that answers a hostname from your pools.

• The domain's DNS must be hosted on Coritan. If the Load balancing tab says No DNS zone, add the domain first.
• Each origin needs a public IPv4 or IPv6 address. Coritan refuses private and reserved addresses.

1. In the dashboard, go to Websites, open the domain and select the Load balancing tab.
2. Under Origin pools, select New pool….
3. Enter a Name that no other pool in the zone has, such as eu-origins. A Description is optional.
4. Choose the Algorithm: Weighted round-robin shares queries by weight, and Failover (by priority) answers from the origin with the lowest priority number (Choosing an origin inside a pool).
5. If a load balancer will use proximity steering, choose the pool's Primary location, the Coritan location nearest its origins.
6. Fill in the first origin under Origins:
   • Address: the server's public IP address, such as 203.0.113.10.
   • Weight: from 1 to 100, for Weighted round-robin.
   • Priority: 0 or more, for Failover (by priority). The lowest number answers first.
7. Choose the origin's Health check and fill in its fields:
   • HTTP or HTTPS: the Path to ask for, such as /healthz, and the Port if it is not 80 for HTTP or 443 for HTTPS.
   • TCP connect: the Port to connect to. Without one, Coritan connects to port 80.
   • Timeout (s): how long the origin has to answer.
8. Select Add origin for each other server, and fill it in the same way. Coritan ignores an origin card with no address.
9. Select Create pool.

Coritan checks every origin that has a health check once a minute, whatever its Every (s) says. The pool's TTL (s) and Session affinity do not change a load balancer's answers, which use the load balancer's own (How DNS load balancing works).

Open the pool's actions menu and select Run health checks. Coritan checks every origin in the pool that has a health check, and the badge beside each origin shows its new status.

• To change a pool or its origins, open the pool's actions menu and select Edit pool…, make the change, then select Save pool. To remove an origin, select the × on its card before you save.
• To stop an origin answering without removing it, turn off Enabled on its card. The scheduled checks skip a disabled origin.
• To stop every load balancer answering from a pool, turn off its Enabled switch in the table, or Pool enabled in the pool's dialog. The load balancers skip it until you turn it back on.
• To delete a pool, open its actions menu, select Delete pool…, type the pool's name and select Delete pool. First remove it from every load balancer that lists it: the dialog names them, and Coritan refuses to delete a pool that one still uses.

The dashboard confirms Pool "eu-origins" created., and the pool appears under Origin pools with its origins and a Health badge such as 2 of 2 healthy. The badge counts the enabled origins that are healthy, or not yet checked.

Pool saved, but could not save 1 origin.

Coritan saved the pool but refused an origin. The dialog stays open and says why for each one; correct the origin and select Save pool again.

health-check target targets a private or reserved network

The origin's address is private or reserved, such as 10.0.0.5. Use the server's public address.

A members require an IPv4 address or AAAA members require an IPv6 address

An origin keeps the address family it was created with. To move it from IPv4 to IPv6, remove it and add a new origin.

Pool name already exists in this zone

Another pool in the zone has that name. Choose a different one.

Pool is referenced by a load balancer; remove it from maps/default/fallback first

A load balancer still lists the pool as a default pool, the fallback pool or in a rule. Edit each load balancer the dialog names, remove the pool, then delete it.

Origin pool limit reached (50) or LB member limit reached (20)

A zone holds up to 50 pools, and a pool up to 20 origins. Delete what you no longer need, or split the origins across pools.

An origin stays unhealthy

Read why in the origin's last_error from the API, such as HTTP 404 (With the API). The check must get a status from 200 to 399 for its path at the origin's IP address. An HTTPS check fails on a certificate that does not include the IP address, so use HTTP or TCP connect for such an origin.

• How DNS load balancing works
• Create a load balancer
• Load balancing reference

Create a pool in zone 42. algorithm is weighted_rr or failover, and primary_location_code is a location code such as the ones the Primary location list shows:

curl -X POST https://api.coritan.com/api/v1/dns/zones/42/pools \
  -H "Authorization: Bearer $CORITAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "eu-origins", "description": "Web servers in Frankfurt", "algorithm": "weighted_rr"}'

The answer is 201 with the pool, which has no origins yet:

{
  "id": 7,
  "zone_id": 42,
  "name": "eu-origins",
  "description": "Web servers in Frankfurt",
  "hostname": null,
  "algorithm": "weighted_rr",
  "ttl": 30,
  "session_affinity": "none",
  "primary_location_code": null,
  "enabled": true,
  "members": [],
  "healthy_members": 0,
  "total_members": 0,
  "created_at": "2026-09-25T09:30:00Z",
  "updated_at": "2026-09-25T09:30:00Z"
}

Add an origin to the pool. Set address_type to AAAA for an IPv6 address; it is A when you leave it out. health_mode is none, http, https or tcp:

curl -X POST https://api.coritan.com/api/v1/dns/zones/42/pools/7/members \
  -H "Authorization: Bearer $CORITAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"address": "203.0.113.10", "weight": 10, "health_mode": "http", "health_path": "/healthz", "health_timeout_s": 5}'

The answer is 201 with the origin. Its health_status is unknown until the first check, or healthy when it has no check. last_check_at and last_error record the latest check.

Run a check now with POST /api/v1/dns/zones/42/pools/7/members/31/health-check, which answers with the origin and its new health_status.

The other calls:

The same calls also work under /api/v1/dns/zones/42/lb-pools, for older clients. A pool created with a hostname also gets a load balancer for that name, with steering off and the pool as its default and fallback pool.