Selecting a different primary replica

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Updated at May 5, 2025

If a cluster has several replicas, you can select a different primary replica (master) as required.

Switching takes on average less than a minute. The cluster may be unavailable for writing for several seconds while switching is taking place.

For more information about selecting a different primary replica, see the MongoDB documentation.

Management console

CLI

REST API

gRPC API

Go to the folder page and select Managed Service for MongoDB.
Click the cluster name and open the Hosts tab.
Click in the PRIMARY host row and select Step down.

If you do not have the Yandex Cloud CLI yet, install and initialize it.

The folder specified when creating the CLI profile is used by default. To change the default folder, use the yc config set folder-id <folder_ID> command. You can specify a different folder using the --folder-name or --folder-id parameter.

To change a cluster's primary replica, run the command:

yc managed-mongodb hosts stepdown <current_primary_replica_name> \
   --name=<cluster_name>

You can request the name of the shard primary replica with the list of cluster hosts and the cluster name, with the list of clusters in the folder.

Get an IAM token for API authentication and put it into the environment variable:
```
export IAM_TOKEN="<IAM_token>"
```

Use the Cluster.StepdownHosts method and send the following request, e.g., via cURL:

curl \
    --request POST \
    --header "Authorization: Bearer $IAM_TOKEN" \
    --header "Content-Type: application/json" \
    --url 'https://mdb.api.cloud.yandex.net/managed-mongodb/v1/clusters/<cluster_ID>:stepdownHosts' \
    --data '{
             "hostNames": [
                "<current_primary_replica_name>"
             ]
            }'

You can get the cluster ID with the list of clusters in the folder, and the name of the shard primary replica, with the list of cluster hosts.

View the server response to make sure the request was successful.

Get an IAM token for API authentication and put it into the environment variable:
```
export IAM_TOKEN="<IAM_token>"
```
Clone the cloudapi repository:
```
cd ~/ && git clone --depth=1 https://github.com/yandex-cloud/cloudapi
```
Below, we assume the repository contents are stored in the ~/cloudapi/ directory.

Use the ClusterService.StepdownHosts call and send the following request, e.g., via gRPCurl:

grpcurl \
    -format json \
    -import-path ~/cloudapi/ \
    -import-path ~/cloudapi/third_party/googleapis/ \
    -proto ~/cloudapi/yandex/cloud/mdb/mongodb/v1/cluster_service.proto \
    -rpc-header "Authorization: Bearer $IAM_TOKEN" \
    -d '{
         "cluster_id": "<cluster_ID>",
         "host_names": [
            "<current_primary_replica_name>"
         ]
        }' \
    mdb.api.cloud.yandex.net:443 \
    yandex.cloud.mdb.mongodb.v1.ClusterService.StepdownHosts

You can get the cluster ID with the list of clusters in the folder, and the name of the shard primary replica, with the list of cluster hosts.

View the server response to make sure the request was successful.

Selecting a different primary replica

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