Scale a Deployment¶

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Considerations
Examples

You can scale your replica set and sharded cluster deployments up or down to match your desired configuration. Scaling up increases the number of members and/or shards in the deployment, thereby improving your deployment’s redundancy and availability. The scale of your deployment is configured in its corresponding custom resource.

Scale a Replica Set

To scale your replica set deployment, set the spec.members setting to the desired number of replica set members. To learn more about replication, see Replication in the MongoDB manual.

Scale a Sharded Cluster

To scale your sharded cluster deployment, set the following settings as desired:

Setting	Description
`spec.shardCount`	Number of shards in the sharded cluster.
`spec.mongodsPerShardCount`	Number of members per shard.
`spec.mongosCount`	Number of Shard Routers.
`spec.configServerCount`	Number of members in the Config Server.

To learn more about sharded cluster configurations, see Sharded Cluster Components in the MongoDB manual.

Considerations¶

The Kubernetes Operator does not support modifying deployment types. For example, you cannot convert a standalone deployment to a replica set. To modify the type of a deployment, we recommend the following procedure:
1. Create the new deployment with the desired configuration.
2. Back up the data from your current deployment.
3. Restore the data from your current deployment to the new deployment.
4. Test your application connections to the new deployment as needed.
5. Once you have verified that the new deployment contains the required data and can be reached by your application(s), bring down the old deployment.
For MongoDB 4.4 deployments using MongoDB Enterprise Kubernetes Operator v1.7.0 and earlier, you can increase or decrease the number of members in a replica set or a sharded cluster by only one member at a time.
Example

To scale a replica set from three members to five members, you must:
1. Change the value of the spec.members setting from 3 to 4.
2. Reapply the configuration to Kubernetes.
3. Change the value of the spec.members setting from 4 to 5.
4. Reapply the configuration to Kubernetes.

Examples¶

Select the desired tab based on the deployment configuration you want to scale:

Replica Set
Sharded Cluster

Consider a replica set resource with the following custom resource:

copy

---
apiVersion: mongodb.com/v1
kind: MongoDB
metadata:
  name: <my-replica-set>
spec:
  members: 3
  version: 4.2.2-ent
  opsManager:
    configMapRef:
      name: <configMap.metadata.name>
            # Must match metadata.name in ConfigMap file
  credentials: <mycredentials>
  type: ReplicaSet
  persistent: true
...

To scale up this replica set and add more members:

Adjust the spec.members setting to the desired number of members:

Important

For MongoDB 4.4 deployments using MongoDB Enterprise Kubernetes Operator v1.7.0 and earlier, you can increase or decrease the number of members in a replica set by only one member at a time.

copy

---
apiVersion: mongodb.com/v1
kind: MongoDB
metadata:
  name: <my-secure-replica-set>
spec:
  members: 4
  version: 4.2.2-ent
  opsManager:
    configMapRef:
      name: <configMap.metadata.name>
  credentials: <mycredentials>
  type: ReplicaSet
  persistent: true
...

Reapply the configuration to Kubernetes:
copy
```
kubectl apply -f <repl-set-config>.yaml
```

Consider a sharded cluster resource with the following custom resource:

copy

---
apiVersion: mongodb.com/v1
kind: MongoDB
metadata:
  name: <my-sharded-cluster>
spec:
  shardCount: 2
  mongodsPerShardCount: 3
  mongosCount: 2
  configServerCount: 3
  version: 4.2.2-ent
  opsManager:
    configMapRef:
      name: <configMap.metadata.name>
            # Must match metadata.name in ConfigMap file
  credentials: <mycredentials>
  type: ShardedCluster
  persistent: true
...

To scale up this sharded cluster:

Adjust the following settings to the desired values:

Important

For MongoDB 4.4 deployments, you can increase or decrease the number of members in a sharded cluster by only one member at a time.

copy

---
apiVersion: mongodb.com/v1
kind: MongoDB
metadata:
  name: <my-secure-sharded-cluster>
spec:
  shardCount: 3
  mongodsPerShardCount: 3
  mongosCount: 3
  configServerCount: 4
  version: 4.2.2-ent
  opsManager:
    configMapRef:
      name: <configMap.metadata.name>
  credentials: <mycredentials>
  type: ShardedCluster
  persistent: true
...

Reapply the configuration to Kubernetes:

copy

kubectl apply -f <sharded-cluster-config>.yaml

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