[Yandex Cloud documentation](../../index.md) > [Yandex Managed Service for ClickHouse®](../index.md) > [Step-by-step guides](index.md) > Clusters > Maintenance

# ClickHouse® cluster maintenance

You can manage [maintenance](../concepts/maintenance.md) of a Yandex Managed Service for ClickHouse® cluster.

## Getting a list of maintenance jobs {#list-maintenance}

1. Navigate to **Managed Service for ClickHouse**.
1. Click the name of your cluster and select the **Maintenance** tab.

To view maintenance jobs with a specific status, click **Status** above the maintenance list and select the status you want from the drop-down menu. You can also find a maintenance job by its ID or job name using the search field above the list.

Click an ID to see how the maintenance job affects cluster availability. Look up **Task details** to see how the maintenance job affects users.

## Getting maintenance-related cluster logs {#maintenance-logs}

1. Navigate to **Managed Service for ClickHouse**.
1. Click the name of your cluster and select the **Maintenance** tab.
1. Click the ID of the maintenance job you need.
1. Click **Task logs**.

## Postpone the planned maintenance {#postpone-planned-maintenance}

Maintenance jobs with the **Planned** status have a specific scheduled date and time specified in the **Start date** column. You can reschedule them to a new date and time if needed.

{% list tabs group=instructions %}

- Management console {#console}

    To reschedule maintenance for a new date and time:

    1. Navigate to **Managed Service for ClickHouse**.
    1. Click the name of your cluster and select the **Maintenance** tab.
    1. Click ![image](../../_assets/console-icons/ellipsis.svg) next to the maintenance job with the **Planned** status.
    1. In the drop-down menu, select ![image](../../_assets/console-icons/arrow-uturn-cw-right.svg) **Postpone**.
    1. In the window that opens:
        * To postpone the maintenance until the next available window, click **Next window** and then **Reschedule**.
        * To reschedule maintenance to a specific UTC date and time, click **Choose date (UTC)**, then select a new date and time interval and click **Reschedule**.

- CLI {#cli}

    If you do not have the Yandex Cloud CLI yet, [install and initialize it](../../cli/quickstart.md#install).

    The folder used by default is the one specified when [creating](../../cli/operations/profile/profile-create.md) the CLI profile. To change the default folder, use the `yc config set folder-id <folder_ID>` command. You can also specify a different folder for any command using `--folder-name` or `--folder-id`. If you access a resource by its name, the search will be limited to the default folder. If you access a resource by its ID, the search will be global, i.e., through all folders based on access permissions.

    To reschedule maintenance for a new date and time:

    1. See the description of the CLI command for rescheduling maintenance :

        ```bash
        yc managed-clickhouse cluster reschedule-maintenance --help
        ```

    1. To reschedule maintenance to the next available window, run this command using the `next-available-window` reschedule type. To reschedule to a specific date and time, use the `specific-time` reschedule type:

        ```bash
        yc managed-clickhouse cluster reschedule-maintenance <cluster_name_or_ID> \
           --reschedule-type <reschedule_type> \
           --delayed-until <timestamp>
        ```

        The timestamp must be in one of the following formats:
        * [RFC-3339](https://www.ietf.org/rfc/rfc3339.txt)
        * `HH:MM:SS`
        * Maintenance time offset in hours and minutes.

        For example, `2006-01-02T15:04:05Z`, `15:04:05`, `2h`, or `3h30m ago`. With the `next-available-window` reschedule type, you do not need to specify `--delayed-until`.

        You can get the cluster name and ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

- REST API {#api}

    To reschedule maintenance for a new date and time:

    1. [Get an IAM token for API authentication](../api-ref/authentication.md) and put it into an environment variable:

        ```bash
        export IAM_TOKEN="<IAM_token>"
        ```

    1. Call the [Cluster.RescheduleMaintenance](../api-ref/Cluster/rescheduleMaintenance.md) method, e.g., via the following [cURL](https://curl.se/) request:

        ```bash
        curl \
        --request POST \
        --header "Authorization: Bearer $IAM_TOKEN" \
        --header "Content-Type: application/json" \
        --url 'https://mdb.api.cloud.yandex.net/managed-clickhouse/v1/clusters/<cluster_ID>:rescheduleMaintenance' \
        --data '{
                    "rescheduleType": <reschedule_type>,
                    "delayedUntil": <timestamp>
                }'
        ```

        Where `rescheduleType` is the reschedule type that can be one of the  following values:

        * `NEXT_AVAILABLE_WINDOW`: Postpone maintenance until the next available window.
        * `SPECIFIC_TIME`: Move the maintenance to a specific date and time.

        The timestamp must be in [RFC-3339](https://www.ietf.org/rfc/rfc3339.txt) format, e.g., `2006-01-02T15:04:05Z`. When selecting the `NEXT_AVAILABLE_WINDOW` reschedule type, you do not need to specify `delayedUntil`.

        You can get the cluster ID from the [folder’s cluster list](cluster-list.md#list-clusters).

    1. Check the [server response](../api-ref/Cluster/rescheduleMaintenance.md#yandex.cloud.operation.Operation) to make sure your request was successful.

- gRPC API {#grpc-api}

    1. [Get an IAM token for API authentication](../api-ref/authentication.md) and put it into an environment variable:

        ```bash
        export IAM_TOKEN="<IAM_token>"
        ```

    1. Clone the [cloudapi](https://github.com/yandex-cloud/cloudapi) repository:
       
       ```bash
       cd ~/ && git clone --depth=1 https://github.com/yandex-cloud/cloudapi
       ```
       
       Below, we assume that the repository contents reside in the `~/cloudapi/` directory.
    1. Call the [ClusterService.RescheduleMaintenance](../api-ref/grpc/Cluster/rescheduleMaintenance.md) method, e.g., via the following [gRPCurl](https://github.com/fullstorydev/grpcurl) request:

        ```bash
        grpcurl \
          -format json \
          -import-path ~/cloudapi/ \
          -import-path ~/cloudapi/third_party/googleapis/ \
          -proto ~/cloudapi/yandex/cloud/mdb/clickhouse/v1/cluster_service.proto \
          -rpc-header "Authorization: Bearer $IAM_TOKEN" \
          -d '{
                "cluster_id": "<cluster_ID>",
                "reschedule_type": <reschedule_type>,
                "delayed_until": <timestamp>
              }' \
          mdb.api.cloud.yandex.net:443 \
          yandex.cloud.mdb.clickhouse.v1.ClusterService.RescheduleMaintenance
        ```

        Where `reschedule_type` is the reschedule type that can be one of the following values:

        * `NEXT_AVAILABLE_WINDOW`: Move the maintenance to the nearest window.
        * `SPECIFIC_TIME`: Move the maintenance to a specific date and time.

        The timestamp must be in [RFC-3339](https://www.ietf.org/rfc/rfc3339.txt) format, e.g., `2006-01-02T15:04:05Z`. When selecting the `NEXT_AVAILABLE_WINDOW` reschedule type, you do not need to specify `delayed_until`.

        You can get the cluster ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

    1. Check the [server response](../api-ref/grpc/Cluster/rescheduleMaintenance.md#yandex.cloud.mdb.clickhouse.v1.Cluster) to make sure your request was successful.

{% endlist %}

## Starting scheduled maintenance immediately {#exec-planned-maintenance}

If necessary, you can run a maintenance job with the **Planned** status immediately, prior to the time specified in the **Start date** column.

{% list tabs group=instructions %}

- Management console {#console}

    To run a scheduled cluster maintenance job immediately:

    1. Navigate to **Managed Service for&nbsp;ClickHouse**.
    1. Click the name of your cluster and select the **Maintenance** tab.
    1. Click ![image](../../_assets/console-icons/ellipsis.svg) next to the maintenance job you need.
    1. In the drop-down menu, select ![image](../../_assets/console-icons/triangle-right.svg) **Carry out now**.

- CLI {#cli}

    If you do not have the Yandex Cloud CLI yet, [install and initialize it](../../cli/quickstart.md#install).

    The folder used by default is the one specified when [creating](../../cli/operations/profile/profile-create.md) the CLI profile. To change the default folder, use the `yc config set folder-id <folder_ID>` command. You can also specify a different folder for any command using `--folder-name` or `--folder-id`. If you access a resource by its name, the search will be limited to the default folder. If you access a resource by its ID, the search will be global, i.e., through all folders based on access permissions.

    To run a scheduled cluster maintenance job immediately:

    1. See the description of the CLI command for rescheduling maintenance :

        ```bash
        yc managed-clickhouse cluster reschedule-maintenance --help
        ```

    1. Run this command using the `immediate` reschedule type:

        ```bash
        yc managed-clickhouse cluster reschedule-maintenance <cluster_name_or_ID> \
           --reschedule-type immediate
        ```

        You can get the cluster name and ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

- REST API {#api}

    To run a scheduled cluster maintenance job immediately:

    1. [Get an IAM token for API authentication](../api-ref/authentication.md) and put it into an environment variable:

       ```bash
       export IAM_TOKEN="<IAM_token>"
       ```

    1. Call the [Cluster.RescheduleMaintenance](../api-ref/Cluster/rescheduleMaintenance.md) method, e.g., via the following [cURL](https://curl.se/) request:

        ```bash
        curl \
        --request POST \
        --header "Authorization: Bearer $IAM_TOKEN" \
        --header "Content-Type: application/json" \
        --url 'https://mdb.api.cloud.yandex.net/managed-clickhouse/v1/clusters/<cluster_ID>:rescheduleMaintenance' \
        --data '{
                    "rescheduleType": "IMMEDIATE"
                }'
        ```

        You can get the cluster ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

    1. Check the [server response](../api-ref/Cluster/rescheduleMaintenance.md#yandex.cloud.operation.Operation) to make sure your request was successful.

- gRPC API {#grpc-api}

    1. [Get an IAM token for API authentication](../api-ref/authentication.md) and put it into an environment variable:

        ```bash
        export IAM_TOKEN="<IAM_token>"
        ```

    1. Clone the [cloudapi](https://github.com/yandex-cloud/cloudapi) repository:
       
       ```bash
       cd ~/ && git clone --depth=1 https://github.com/yandex-cloud/cloudapi
       ```
       
       Below, we assume that the repository contents reside in the `~/cloudapi/` directory.
    1. Call the [ClusterService.RescheduleMaintenance](../api-ref/grpc/Cluster/rescheduleMaintenance.md) method, e.g., via the following [gRPCurl](https://github.com/fullstorydev/grpcurl) request:

        ```bash
        grpcurl \
          -format json \
          -import-path ~/cloudapi/ \
          -import-path ~/cloudapi/third_party/googleapis/ \
          -proto ~/cloudapi/yandex/cloud/mdb/clickhouse/v1/cluster_service.proto \
          -rpc-header "Authorization: Bearer $IAM_TOKEN" \
          -d '{
                "cluster_id": "<cluster_ID>",
                "reschedule_type": "IMMEDIATE"
              }' \
          mdb.api.cloud.yandex.net:443 \
          yandex.cloud.mdb.clickhouse.v1.ClusterService.RescheduleMaintenance
        ```

        You can get the cluster ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

    1. Check the [server response](../api-ref/grpc/Cluster/rescheduleMaintenance.md#yandex.cloud.mdb.clickhouse.v1.Cluster) to make sure your request was successful.

{% endlist %}

## Configuring a maintenance window {#set-maintenance-window}

By default, maintenance can be scheduled for any time. You can choose a specific day of the week and hour to schedule maintenance. For example, you can choose the time when the cluster is least busy.

{% note warning %}

If a scheduled maintenance does not fall within the new interval, it will be automatically canceled.

{% endnote %}

{% list tabs group=instructions %}

- Management console {#console}

    1. Navigate to **Managed Service for&nbsp;ClickHouse**.
    1. Click the name of your cluster and select the **Maintenance** tab.
    1. Click ![image](../../_assets/console-icons/calendar.svg) **Configure the maintenance window**.
    1. In the window that opens:
        * To allow maintenance at any time, select **At any time**, which is also the default option.
        * To allow weekly maintenance at a specific time, select **By schedule** and specify the weekday and hour in UTC.

- CLI {#cli}

    If you do not have the Yandex Cloud CLI yet, [install and initialize it](../../cli/quickstart.md#install).

    The folder used by default is the one specified when [creating](../../cli/operations/profile/profile-create.md) the CLI profile. To change the default folder, use the `yc config set folder-id <folder_ID>` command. You can also specify a different folder for any command using `--folder-name` or `--folder-id`. If you access a resource by its name, the search will be limited to the default folder. If you access a resource by its ID, the search will be global, i.e., through all folders based on access permissions.

    1. See the description of the CLI command for updating the maintenance window:

        ```bash
        yc managed-clickhouse cluster update --help
        ```

    1. Run this command:

        ```bash
        yc managed-clickhouse cluster update <cluster_name_or_ID> \
           --maintenance-window type=<maintenance_type>,`
                               `day=<day_of_week>,`
                               `hour=<hour>
        ```

        Where `type` is the maintenance type:

        * `anytime`: Any time (default).
        * `weekly`: On a schedule. For this value, also specify the following:
            * `day`: Day of week, i.e., `MON`, `TUE`, `WED`, `THU`, `FRI`, `SAT`, or `SUN`.
            * `hour`: Sequence number of UTC hour interval, from `1` to `24`.
        
              > For example, `1` stands for the interval from `00:00` to `01:00`, and `5`, from `04:00` to `05:00`.

        You can get the cluster name and ID with the [list of clusters in the folder](cluster-list.md#list-clusters).


- Terraform {#tf}

    1. Open the current Terraform configuration file with the infrastructure plan.

        For more on how to create this file, see [Creating a cluster](cluster-create.md).

        For a complete list of configurable Managed Service for ClickHouse® cluster fields, see [this Terraform provider guide](../../terraform/resources/mdb_clickhouse_cluster.md).

    1. To set up the [maintenance window](../concepts/maintenance.md) that will also apply to stopped clusters, add the `maintenance_window` section to the cluster description:
       
       ```hcl
       resource "yandex_mdb_clickhouse_cluster_v2" "<cluster_name>" {
         ...
         maintenance_window {
           type = "<maintenance_type>"
           day  = "<day_of_week>"
           hour = <hour>
         }
         ...
       }
       ```
       
       Where:
       
       * `type`: Maintenance type. The possible values include:
           * `ANYTIME`: Any time.
           * `WEEKLY`: On a schedule.
       * `day`: Day of week for the `WEEKLY` type, i.e., `MON`, `TUE`, `WED`, `THU`, `FRI`, `SAT`, or `SUN`.
       * `hour`: Sequence number of UTC hour interval for the `WEEKLY` type, from `1` to `24`.
       
         > For example, `1` stands for the interval from `00:00` to `01:00`, and `5`, from `04:00` to `05:00`.

    1. Make sure the settings are correct.

        1. In the command line, navigate to the directory that contains the current Terraform configuration files defining the infrastructure.
        1. Run this command:
        
           ```bash
           terraform validate
           ```
        
           Terraform will show any errors found in your configuration files.

    1. Confirm updating the resources.

        1. Run this command to view the planned changes:
        
           ```bash
           terraform plan
           ```
        
           If you described the configuration correctly, the terminal will display a list of the resources to update and their parameters. This is a verification step that does not apply changes to your resources.
        
        1. If everything looks correct, apply the changes:
           1. Run this command:
        
              ```bash
              terraform apply
              ```
        
           1. Confirm updating the resources.
           1. Wait for the operation to complete.

        {% note warning "Timeouts" %}
        
        The Terraform provider sets the following timeouts for Managed Service for ClickHouse® cluster operations:
        
        * Creating a cluster, including by restoring from a backup: 60 minutes.
        * Updating a cluster: 90 minutes.
        * Deleting a cluster: 30 minutes.
        
        Operations exceeding the timeout are aborted.
        
        {% cut "How to change these limits" %}
        
        Add the `timeouts` section to your cluster description, such as the following:
        
        ```hcl
        resource "yandex_mdb_clickhouse_cluster_v2" "<cluster_name>" {
          ...
          timeouts = {
            create = "1h30m" # 1 hour 30 minutes
            update = "2h"    # 2 hours
            delete = "30m"   # 30 minutes
          }
        }
        ```
        
        {% endcut %}
        
        {% endnote %}


- REST API {#api}

    1. [Get an IAM token for API authentication](../api-ref/authentication.md) and put it into an environment variable:

        ```bash
        export IAM_TOKEN="<IAM_token>"
        ```

    1. Call the [Cluster.Update](../api-ref/Cluster/update.md) method, e.g., via the following [cURL](https://curl.se/) request:

        {% note warning %}
        
        The API method will assign default values to all the parameters of the object you are modifying unless you explicitly provide them in your request. To avoid this, list the settings you want to change in the `updateMask` parameter as a single comma-separated string.
        
        {% endnote %}

        ```bash
        curl \
          --request PATCH \
          --header "Authorization: Bearer $IAM_TOKEN" \
          --header "Content-Type: application/json" \
          --url 'https://mdb.api.cloud.yandex.net/managed-clickhouse/v1/clusters/<cluster_ID>' \
          --data '{
                    "updateMask": "maintenanceWindow",
                    "maintenanceWindow": {
                      "weeklyMaintenanceWindow": {
                        "day": "<day_of_week>",
                        "hour": "<hour>"
                      }
                    }
                  }'
        ```

        Where:

        * `updateMask`: Comma-separated string of settings to update.

            Here, we provide only one setting.

        * `maintenanceWindow`: [Maintenance](../concepts/maintenance.md) window settings, including for stopped clusters. In `maintenanceWindow`, provide one of these two parameters:

            * `anytime`: Maintenance can be scheduled for any time.
            * `weeklyMaintenanceWindow`: Maintenance can only be scheduled for a specific day of week and hour:

                * `day`: Day of week in `DDD` format, i.e., `MON`, `TUE`, `WED`, `THU`, `FRI`, `SAT`, or `SUN`.
                * `hour`: Time of day (UTC) in `HH` format, from `1` to `24`.

        You can get the cluster ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

    1. Check the [server response](../api-ref/Cluster/update.md#yandex.cloud.operation.Operation) to make sure your request was successful.

- gRPC API {#grpc-api}

    1. [Get an IAM token for API authentication](../api-ref/authentication.md) and put it into an environment variable:

        ```bash
        export IAM_TOKEN="<IAM_token>"
        ```

    1. Clone the [cloudapi](https://github.com/yandex-cloud/cloudapi) repository:
       
       ```bash
       cd ~/ && git clone --depth=1 https://github.com/yandex-cloud/cloudapi
       ```
       
       Below, we assume that the repository contents reside in the `~/cloudapi/` directory.
    1. Call the [ClusterService.Update](../api-ref/grpc/Cluster/update.md) method, e.g., via the following [gRPCurl](https://github.com/fullstorydev/grpcurl) request:

       {% note warning %}
       
       The API method will assign default values to all the parameters of the object you are modifying unless you explicitly provide them in your request. To avoid this, list the settings you want to change in the `update_mask` parameter as an array of `paths[]` strings.
       
       {% cut "Format for listing settings" %}
       
       ```yaml
       "update_mask": {
           "paths": [
               "<setting_1>",
               "<setting_2>",
               ...
               "<setting_N>"
           ]
       }
       ```
       
       {% endcut %}
       
       {% endnote %}

        ```bash
        grpcurl \
          -format json \
          -import-path ~/cloudapi/ \
          -import-path ~/cloudapi/third_party/googleapis/ \
          -proto ~/cloudapi/yandex/cloud/mdb/clickhouse/v1/cluster_service.proto \
          -rpc-header "Authorization: Bearer $IAM_TOKEN" \
          -d '{
                "cluster_id": "<cluster_ID>",
                "update_mask": {
                  "paths": ["maintenance_window"]
                },
                "maintenance_window": {
                  "weekly_maintenance_window": {
                    "day": "<day_of_week>",
                    "hour": "<hour>"
                  }
                }
              }' \
          mdb.api.cloud.yandex.net:443 \
          yandex.cloud.mdb.clickhouse.v1.ClusterService.Update
        ```

        Where:

        * `update_mask`: List of settings you want to update as an array of strings (`paths[]`).

            Here, we provide only one setting.

        * `maintenance_window`: [Maintenance](../concepts/maintenance.md) window settings, including for stopped clusters. In `maintenance_window`, provide one of these two parameters:

            * `anytime`: Maintenance can be scheduled for any time.
            * `weekly_maintenance_window`: Maintenance can only be scheduled for a specific day of week and hour:

                * `day`: Day of week in `DDD` format, i.e., `MON`, `TUE`, `WED`, `THU`, `FRI`, `SAT`, or `SUN`.
                * `hour`: Time of day (UTC) in `HH` format, from `1` to `24`.

        You can get the cluster ID with the [list of clusters in the folder](cluster-list.md#list-clusters).

    1. Check the [server response](../api-ref/grpc/Cluster/update.md#yandex.cloud.mdb.clickhouse.v1.Cluster) to make sure your request was successful.

{% endlist %}

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