# Add node even when seed is unreachable

**URL:** <https://forum.scylladb.com/t/add-node-even-when-seed-is-unreachable/1040>\
**Category:** ScyllaDB\
**Tags:** open-source\
**Created:** [November 27, 2023, 11:02am UTC](https://forum.scylladb.com/t/add-node-even-when-seed-is-unreachable/1040 "2023-11-27T11:02:19Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![ronharel](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.scylladb.com/ronharel/32/539_2.png) [@ronharel](https://forum.scylladb.com/u/ronharel)\
**Post date:** [November 27, 2023, 11:02am UTC](https://forum.scylladb.com/t/add-node-even-when-seed-is-unreachable/1040/1 "2023-11-27T11:02:19Z")

</div>

Hi,  
Is there any way to add a new node to the cluster even when one of it’s configured seeds isn’t reachable but the rest are? e.g. typo…

---

<div class="post-metadata">

**Author:** ![felipemendes](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.scylladb.com/felipemendes/32/11_2.png) [@felipemendes](https://forum.scylladb.com/u/felipemendes)\
**Post date:** [November 27, 2023, 12:37pm UTC](https://forum.scylladb.com/t/add-node-even-when-seed-is-unreachable/1040/2 "2023-11-27T12:37:01Z")

</div>

Let’s try it out…

```shell
% cat unreachable-seeds.yml 
version: "3"

services:
  scylla-node1:
    container_name: node1
    image: scylladb/scylla:5.2.10
    restart: always
    command: --seeds=node1 --smp 1 --memory 1G --overprovisioned 1 --api-address 0.0.0.0 --endpoint-snitch GossipingPropertyFileSnitch
    networks:
      - web
    volumes: 
      - ./cassandra-rackdc.properties:/etc/scylla/cassandra-rackdc.properties
    healthcheck:
      test: ["CMD-SHELL", "sh -c $(curl -s -X GET --header 'Accept: application/json' 'http://localhost:10000/storage_service/native_transport')"]
      interval: 30s
      timeout: 10s
      retries: 5

  scylla-node2:
    container_name: node2
    image: scylladb/scylla:5.2.10
    restart: always
    command: --seeds=node1 --smp 1 --memory 1G --overprovisioned 1 --api-address 0.0.0.0 --endpoint-snitch GossipingPropertyFileSnitch
    networks:
      - web
    volumes: 
      - ./cassandra-rackdc.properties:/etc/scylla/cassandra-rackdc.properties
    healthcheck:
      test: ["CMD-SHELL", "sh -c $(curl -s -X GET --header 'Accept: application/json' 'http://localhost:10000/storage_service/native_transport')"]
      interval: 30s
      timeout: 10s
      retries: 5
    depends_on:
      scylla-node1:
        condition: service_healthy

  scylla-node3:
    container_name: node3
    image: scylladb/scylla:5.2.10
    restart: always
    command: --seeds=172.17.0.155,172.22.0.156,node2,172.21.0.50,172.21.0.1 --smp 1 --memory 1G --overprovisioned 1 --api-address 0.0.0.0 --endpoint-snitch GossipingPropertyFileSnitch
    networks:
      - web
    volumes: 
      - ./cassandra-rackdc.properties:/etc/scylla/cassandra-rackdc.properties
    healthcheck:
      test: ["CMD-SHELL", "sh -c $(curl -s -X GET --header 'Accept: application/json' 'http://localhost:10000/storage_service/native_transport')"]
      interval: 30s
      timeout: 10s
      retries: 5
    depends_on:
      scylla-node2:
        condition: service_healthy

networks:
  web:
    driver: bridge

```

In the above configuration, **scylla-node3** has 4 invalid seeds: 3 from different subnets and unreachable, one from the local network (which is the GW), and node2 (the only valid entry). Note we haven’t specified an invalid FQDN here, as that would fail the DNS lookup.

```shell
% docker compose -f unreachable.yml up -d
[+] Running 2/3
 ⠿ Container node1 Healthy 32.0s
 ⠿ Container node2 Healthy 152.7s
 ⠿ Container node3 Started 153.0s

```

Then:

```shell
% docker exec -it node3 nodetool status
Datacenter: dc
==============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns Host ID Rack
UN 172.21.0.4 624 KB 256 ? 1c0dff39-e5f2-4960-98c4-e1838f6cf673 r1
UN 172.21.0.3 ? 256 ? 67088527-d288-4ee3-8e0c-7f1af9258669 r1
UN 172.21.0.2 260 KB 256 ? acaf2b17-c66a-4034-a083-644a775a931a r1

Note: Non-system keyspaces don't have the same replication settings, effective ownership information is meaningless

```

Hope it helps!

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<div class="post-metadata">

**Author:** ![ronharel](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.scylladb.com/ronharel/32/539_2.png) [@ronharel](https://forum.scylladb.com/u/ronharel)\
**Post date:** [November 27, 2023, 1:04pm UTC](https://forum.scylladb.com/t/add-node-even-when-seed-is-unreachable/1040/3 "2023-11-27T13:04:34Z")

</div>

Thats great, when I originally tried it I failed on DNS lookup which wasn’t obvious from the logs.  
Thanks!

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<div class="post-metadata">

**Author:** ![ronharel](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.scylladb.com/ronharel/32/539_2.png) [@ronharel](https://forum.scylladb.com/u/ronharel)\
**Post date:** [December 4, 2023, 12:26pm UTC](https://forum.scylladb.com/t/add-node-even-when-seed-is-unreachable/1040/4 "2023-12-04T12:26:48Z")

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I will quickly note for anyone visiting this topic in the future, that this is still a problem in the context of the first node of the cluster.  
see [this issue](https://github.com/scylladb/scylladb/issues/1679).