Scaling your ArangoDB deployment

The ArangoDB Kubernetes Operator allows easily scale the number of DB-Servers and Coordinators up or down as needed.

The scale up or down, change the number of servers in the custom resource.

E.g., change spec.dbservers.count from 3 to 4.

Then apply the updated resource using:

kubectl apply -f {your-arango-deployment}.yaml

Inspect the status of the custom resource to monitor the progress of the scaling operation.

Note: It is not possible to change the number of Agency servers after creating a cluster. Make sure to specify the desired number when creating CR first time.



When increasing the count, operator will try to create missing pods. When scaling up, make sure that you have enough computational resources / nodes, otherwise pod will be stuck in Pending state.


Scaling down is always done one server at a time.

Scale down is possible only when all other actions on ArangoDeployment are finished.

The internal process followed by the ArangoDB operator when scaling down is as follows:

  • It chooses a member to be evicted. First, it will try to remove unhealthy members or fall-back to the member with the highest deletion_priority (check Use deletion_priority to control scale-down order).
  • Making an internal calls, it forces the server to resign leadership. In case of DB servers it means that all shard leaders will be switched to other servers.
  • Wait until server is cleaned out from the cluster.
  • Pod finalized.

Use deletion_priority to control scale-down order

You can use .spec.deletion_priority field in ArangoMember CR to control the order in which servers are scaled down. Refer to ArangoMember API Reference for more details.