General questions about Managed Service for ClickHouse®

• What is Managed Service for ClickHouse®?

• What is ClickHouse® used for? Which DBMS should I select?

• What is the role of Managed Service for ClickHouse® in database management and maintenance?

• Not sure whether to use Managed Service for ClickHouse® or VMs running databases?

• What is a database host and database cluster?

• How do I get started with Managed Service for ClickHouse®?

• How many database hosts can be in a cluster?

• How can I access a running database host?

• How many clusters can I create within a single cloud?

• How are database clusters maintained?

• How do I edit external dictionaries?

• Which ClickHouse® version does Managed Service for ClickHouse® use?

• Which ClickHouse® version should I choose?

• What happens when a new DBMS version is released?

• What happens when a DBMS version becomes deprecated?

• How do you calculate usage cost for a database host?

• How much does it cost to use my cluster?

• How can I change the computing resources and storage size for a database cluster?

• How can I fix the no permission error when attaching a service account to a cluster?

• How do I get the logs of my activity in the Yandex Cloud services?

What is Managed Service for ClickHouse®?What is Managed Service for ClickHouse®?

Managed Service for ClickHouse® is a solution that helps you create, operate, and scale ClickHouse® databases in the cloud.

With Managed Service for ClickHouse®, you can:

• Create a database with performance tailored to your needs.
• Scale your database compute and dedicated storage capacity as needed.
• Get database logs.

Managed Service for ClickHouse® takes over time-consuming administrative tasks in ClickHouse®:

• Monitors your resource consumption.
• Automatically backs up your databases.
• Ensures fault tolerance through automatic failover to standby replicas.
• Keeps your DBMS software up to date.

You work with a Managed Service for ClickHouse® database cluster just like with your regular local database. Thus, you can manage internal database settings to meet your application requirements.

What is ClickHouse® used for? Which DBMS should I select?What is ClickHouse® used for? Which DBMS should I select?

ClickHouse® is designed primarily for analytics (OLAP) and only supports adding and reading data. You can update data but with certain limitations. For other purposes, you might want to use another DBMS.

What is the role of Managed Service for ClickHouse® in database management and maintenance?What is the role of Managed Service for ClickHouse® in database management and maintenance?

When you create clusters, Managed Service for ClickHouse® allocates resources, installs the DBMS, and creates databases.

For all created and running databases, Managed Service for ClickHouse® automatically creates backups as well as applies DBMS patches and updates.

Furthermore, Managed Service for ClickHouse® ensures data replication across database hosts, both within and across availability zones, with automatic failover to a standby replica if a failure occurs.

Be mindful of what is what is controlled by the service, and what by the Yandex Cloud customer. Understanding these control zones will help you use your cloud resources effectively and avoid potential database-related problems. For more information, see Zones of control between managed database (MDB) service users and Yandex Cloud.

Not sure whether to use Managed Service for ClickHouse® or VMs running databases?Not sure whether to use Managed Service for ClickHouse® or VMs running databases?

Yandex Cloud offers two ways to work with databases:

• With Managed Service for ClickHouse®, you can use template databases, with no administrative effort required.
• With Yandex Compute Cloud virtual machines, you can create and customize your own databases. This approach allows you to use any database management system, connect to databases over SSH, and many more.

What is a database host and database cluster?What is a database host and database cluster?

A database host is a cloud-based isolated database environment with dedicated computing resources and reserved storage capacity.

A database cluster consists of one or more database hosts with configurable replication across them.

How do I get started with Managed Service for ClickHouse®?How do I get started with Managed Service for ClickHouse®?

Managed Service for ClickHouse® is available to all registered Yandex Cloud users.

Before creating a database cluster in Managed Service for ClickHouse®, you need to decide on its configuration:

• Host class that will determine your computing power, i.e., vCPUs, RAM, and more.
• Storage size (fully reserved when creating the cluster).
• Network for your cluster.
• Number of hosts in your cluster and availability zone for each host.

For more information, see Getting started.

How many database hosts can be in a cluster?How many database hosts can be in a cluster?

The minimum number of hosts in a cluster depends on the following:

• Storage type:

  • At least three hosts for non-replicated SSDs (network-ssd-nonreplicated).

  • At least two hosts for local SSDs (local-ssd).

  • At least one host for the following disk types:

    • Network HDDs (network-hdd)
    • Network SSDs (network-ssd)
    • Ultra high-speed network SSDs with three replicas (network-ssd-io-m3)

• Cluster sharding. When sharding is enabled, you need to multiply the minimum number of hosts for the selected disk type by the number of shards.

  For more information on the features and limitations of sharding in ClickHouse®, see this article.

The maximum number of hosts per cluster cannot exceed the set limits.

For more information, see Quotas and limits.

How can I access a running database host?How can I access a running database host?

You can connect to Managed Service for ClickHouse® databases using conventional DBMS methods.

Learn more about connecting to clusters in this guide.

How many clusters can I create within a single cloud?How many clusters can I create within a single cloud?

To learn more about MDB technical and organizational limitations, see Quotas and limits.

How are database clusters maintained?How are database clusters maintained?

Maintenance in Managed Service for ClickHouse® includes:

• Automatic installation of DBMS updates and patches for all hosts, even disabled ones.
• Changes in the host class and storage size.
• Other Managed Service for ClickHouse® maintenance activities.

For more information, see Maintenance.

How do I edit external dictionaries?How do I edit external dictionaries?

To rename a dictionary, run this query:

RENAME DICTIONARY <dictionary_name> TO <new_name>

For other changes, use the update API method.

Which ClickHouse® version does Managed Service for ClickHouse® use?Which ClickHouse® version does Managed Service for ClickHouse® use?

Managed Service for ClickHouse® uses multiple latest stable versions of ClickHouse®. For more information, see ClickHouse® versioning policy.

Which ClickHouse® version should I choose?Which ClickHouse® version should I choose?

We recommend the latest available LTS version of ClickHouse®. For more information, see ClickHouse® versioning policy.

What happens when a new DBMS version is released?What happens when a new DBMS version is released?

When new minor versions are released, the cluster software is automatically updated after a short testing period.

Owners of affected database clusters are notified of an expected maintenance period and database availability in advance.

What happens when a DBMS version becomes deprecated?What happens when a DBMS version becomes deprecated?

When a DBMS version becomes deprecated, Managed Service for ClickHouse® automatically sends email notifications to the owners of database clusters created with this version.

New hosts can no longer be created using deprecated DBMS versions. Clusters running a deprecated ClickHouse® version are updated according to the versioning policy.

Owners of affected database clusters are notified of an expected maintenance period and database availability in advance.

How do you calculate usage cost for a database host?How do you calculate usage cost for a database host?

In Managed Service for ClickHouse®, the usage cost is calculated based on the following:

• Selected host class.
• Reserved storage capacity for the database host.
• Size of database cluster backups. You are not charged for storing backups up to your storage size. Additional backup storage is charged according to our pricing policy.
• Database host uptime in hours. Partial hours are rounded to the nearest whole hour. For the cost per hour of operation for each host class, see our pricing policy.

How much does it cost to use my cluster?How much does it cost to use my cluster?

In the management console, navigate to the folder dashboard, select Managed Service for ClickHouse, and click the cluster you need. On the right side of the screen, you will see the cluster usage cost per month. For more information, see our pricing policy.

How can I change the computing resources and storage size for a database cluster?How can I change the computing resources and storage size for a database cluster?

You can scale your computing resources and storage size directly in the management console by selecting a different host class for your cluster.

The cluster settings will update within 30 minutes. This window may also be used for other maintenance activities, such as installing updates.

How can I fix the no permission error when attaching a service account to a cluster?How can I fix the no permission error when attaching a service account to a cluster?

Error message:

ERROR: rpc error: code = PermissionDenied desc = you do not have permission to access the requested service account or service account does not exist

The error occurs in the following cases:

• You are creating or modifying a cluster and linking it to a service account.
• You are restoring a cluster linked to a service account from its backup.

To fix this error, assign your Yandex Cloud account the iam.serviceAccounts.user role or higher.

Does the service meet the requirements of the Russian Federation Federal Law 152-FZ on personal data?Does the service meet the requirements of the Russian Federation Federal Law 152-FZ on personal data?

Yes, it does. You can read the full security audit conclusion here.

Can I get logs of my operations in Yandex Cloud?Can I get logs of my operations in Yandex Cloud?

Yes, you can request information about operations with your resources from Yandex Cloud logs. Do it by contacting support.

ClickHouse® is a registered trademark of ClickHouse, Inc.