General questions about Managed Service for ClickHouse®

• What is Managed Service for ClickHouse®?

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

• What part of database management and maintenance is Managed Service for ClickHouse® responsible for?

• Which tasks are best addressed using Managed Service for ClickHouse®, and which using VMs with databases?

• What is a database host and database cluster?

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

• How many database hosts can there be in one cluster?

• How can I access a running DB host?

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

• How are DB 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 connecting a service account to the cluster?

• How do I get the logs of my actions in the services?

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

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

With Managed Service for ClickHouse®, you can:

• Create a database with the required performance characteristics.
• Scale processing power and storage dedicated for your databases as needed.
• Get database logs.

Managed Service for ClickHouse® takes on time-consuming ClickHouse® infrastructure administration tasks:

• Monitors resource usage.
• Automatically creates DB backups.
• Provides fault tolerance through automatic failover to backup replicas.
• Keeps database software updated.

You interact with database clusters in Managed Service for ClickHouse® the same way you interact with regular databases in your local infrastructure. This allows you to manage internal database settings to meet your app 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 limitations. For other purposes, you might want to use other managed DB services.

What part of database management and maintenance is Managed Service for ClickHouse® responsible for?What part of database management and maintenance is Managed Service for ClickHouse® responsible for?

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

For the created and running databases, Managed Service for ClickHouse® automatically creates backups and applies fixes and updates to the DBMS.

Managed Service for ClickHouse® also allows you to replicate data between database hosts (both within and across availability zones) and automatically routes the load to a backup replica in the event of a failure.

Which tasks are best addressed using Managed Service for ClickHouse®, and which using VMs with databases?Which tasks are best addressed using Managed Service for ClickHouse®, and which using VMs with databases?

Yandex Cloud offers two ways to work with databases:

• Managed Service for ClickHouse® allows you to operate template databases with no need to worry about administration.
• Yandex Compute Cloud virtual machines allow you to create and configure your own databases. This approach allows you to use any database management systems, access databases via SSH, etc.

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

A database host is an isolated database environment in the cloud infrastructure with dedicated computing resources and reserved data storage.

A database cluster is one or more database hosts between which you can configure replication.

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 any registered Yandex Cloud user.

To create a database cluster in Managed Service for ClickHouse®, you need to define its parameters:

• Host class (performance characteristics, such as CPUs, RAM, etc.).
• Storage size (reserved to the full extent when you create a cluster).
• Network your cluster will be connected to.
• Number of hosts for the cluster and the availability zone for each host.

For more information, see Getting started.

How many database hosts can there be in one cluster?How many database hosts can there be in one cluster?

The minimum number of hosts depends on the selected type of storage:

• 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:

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

The maximum number of hosts per cluster is subject to the limits in place.

For more information, see Quotas and limits.

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

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

Learn more about connecting to clusters.

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

For more information on MDB technical and organizational limitations, see Quotas and limits.

How are DB clusters maintained?How are DB clusters maintained?

In Managed Service for ClickHouse®, maintenance implies:

• Automatic installation of DBMS updates and revisions for DB hosts (including disabled clusters).
• Changes to 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 the 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 some of the 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 the affected DB clusters are notified of expected work times and DB 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 on a deprecated version of ClickHouse® are updated according to the versioning policy.

Owners of the affected DB clusters are notified of expected work times and DB 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 parameters:

• Selected host class.
• Size of the storage reserved for the database host.
• Size of the database cluster backups. Backup size equal to the storage size is free of charge. Backup storage that exceeds this size is charged at special rates.
• Number of hours of database host operation. Partial hours are rounded to an integer value. You can find the cost per hour for each host class in the Pricing policy section.

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

In the management console, go to the folder page, select Managed Service for ClickHouse, and click the appropriate cluster. On the right side of the screen, you will see the cluster usage cost per month. For more information, see 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 change computing resources and storage size in the management console. All you need to do is choose a different host class for the required cluster.

The cluster characteristics change within 30 minutes. During this period, other maintenance activities may also be enabled for the cluster, such as installing updates.

How can I fix the no permission error when connecting a service account to the cluster?How can I fix the no permission error when connecting a service account to the 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 the logs of what I do when I work with Yandex Cloud?Can I get the logs of what I do when I work with Yandex Cloud?

Yes, you can request information about operations with your resources from Yandex Cloud. For more information, see Data requests.

ClickHouse® is a registered trademark of ClickHouse, Inc.