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Replacing a Dead Seed NodeCopy
Note
The seed concept in gossip has been removed.
A seed node is only used by a new node during startup to learn about the cluster topology. As a result, there’s no need
to replace the node configured with the seeds parameter in the scylla.yaml file.
In ScyllaDB, it is not possible to bootstrap a seed node. The following steps describe how to replace a dead seed node.
PrerequisitesCopy
Verify that the node is listed as a seed node in the scylla.yaml file by running the following command:
cat /etc/scylla/scylla.yaml | grep seeds:
If the dead node’s IP address is in the seeds list, it needs to be replaced.
ProcedureCopy
Perform steps 1-3 for all the nodes in the cluster:
Promote an existing node from the cluster to be a seed node by adding the node IP to the seed list in the
scylla.yamlfile in/etc/scylla/.Remove the dead node IP from the seeds providers list. See Remove a Seed Node from Seed List for instructions.
Restart the node in the cluster by running the following command:
sudo systemctl restart scylla-server
docker exec -it some-scylla supervisorctl restart scylla
(without restarting some-scylla container)
Note
This operation needs to be performed on all the nodes in the cluster. For this reason, you need to orchestrate the procedure so that only a small number of nodes are restarted simultaneously. Use
nodetool statusto verify that restarted nodes are online before restarting more nodes. If too many nodes are offline, the cluster may suffer temporary service degradation or outage.Replace the dead node using the dead node replacement procedure.
Your cluster should have more than one seed node, but it’s not allowed to define all the nodes in the cluster to be seed nodes.