FAQ about Yandex StoreDoc

General questionsGeneral questions

• What is Yandex StoreDoc?

• What is Yandex StoreDoc's share of database management and maintenance work?

• Not sure when to use Yandex StoreDoc or VMs with databases?

• What is a database host and database cluster?

• How do I get started with Yandex StoreDoc?

• 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?

• Which Yandex StoreDoc version does Yandex StoreDoc use?

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

• Is database host backup enabled by default?

• When are backups performed? Is a database cluster available during a backup?

• Can I change the retention period of automatic backups?

• What metrics and processes can be tracked using monitoring?

• How do I set up an alert that triggers as soon as a certain percentage of disk space has been used up?

Questions about Yandex StoreDocQuestions about Yandex StoreDoc

• Why should I use Yandex StoreDoc in Yandex StoreDoc rather than my own VM-based installation?

• What happens to a cluster if one of its hosts fails?

• Can I deploy a Yandex StoreDoc cluster in multiple availability zones?

• What is the backup procedure for Yandex StoreDoc clusters?

• How does replication work for Yandex StoreDoc?

• What limitations are there for Yandex StoreDoc clusters?

• Why is the cluster slow even though the computing resources are not used up?

• How do I get access to the local.oplog.rs service collection?

• Can I connect to cluster hosts via SSH or get superuser permissions on hosts?

• What should I do if I get the revocation check error when using PowerShell to obtain an SSL certificate?

General questionsGeneral questions

What is Yandex StoreDoc?What is Yandex StoreDoc?

Yandex StoreDoc is a solution that helps you create, operate, and scale Yandex StoreDoc databases in the cloud.

With Yandex StoreDoc, you can:

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

Yandex StoreDoc takes over time-consuming Yandex StoreDoc infrastructure administration tasks:

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

You work with a Yandex StoreDoc database cluster as if it were a regular database in your local infrastructure This allows you to manage internal database settings to meet your app requirements.

What is Yandex StoreDoc's share of database management and maintenance work?What is Yandex StoreDoc's share of database management and maintenance work?

When you create clusters, Yandex StoreDoc allocates resources, installs the DBMS, and creates databases.

For all created and running databases, Yandex StoreDoc automatically creates backups and applies fixes and updates.

Yandex StoreDoc also provides data replication between database hosts (both inside and between availability zones) and automatically switches the load over to a backup replica in the event of a failure.

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 Yandex StoreDoc or VMs running databases?Not sure whether to use Yandex StoreDoc or VMs running databases?

Yandex Cloud offers two ways to work with databases:

• Yandex StoreDoc: Enables you to operate template databases without needing to manage their 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, and so on.

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 with dedicated computing resources and reserved storage capacity.

A database cluster is one or more database hosts with the option to configure replication.

How do I get started with Yandex StoreDoc?How do I get started with Yandex StoreDoc?

Yandex StoreDoc is available to all registered Yandex Cloud users.

To create a database cluster in Yandex StoreDoc, you need to define its settings:

• Host class (performance parameters, such as CPUs, RAM, etc.).
• Disk type and size (reserved in full when creating a cluster).
• Network your cluster will be connected to.
• Number of hosts for the cluster and the availability zone for each of them.

For detailed instructions, see Getting started with Yandex StoreDoc.

How many database hosts does a cluster support?How many database hosts does a cluster support?

The minimum number of hosts per cluster depends on the following:

• Selected platform and host class.
• Selected disk type.

The maximum number of hosts in a cluster is only limited by the requested computing resources and the size of the storage for the cluster.

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 Yandex StoreDoc databases using standard DBMS methods.

Learn more about connecting to clusters here.

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 Yandex StoreDoc, maintenance implies:

• Automatic installation of DBMS updates and fixes for DB hosts (including disabled clusters).
• Changes to the host class and storage size.
• Other Yandex StoreDoc maintenance activities.

For more information, see Maintenance.

Which Yandex StoreDoc version does Yandex StoreDoc use?Which Yandex StoreDoc version does Yandex StoreDoc use?

Yandex StoreDoc supports Yandex StoreDoc versions 6.0 and 7.0.

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 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?

One month after the database version becomes deprecated, Yandex StoreDoc automatically sends email notifications to the owners of DB clusters created with this version.

New hosts can no longer be created using deprecated DBMS versions. Database clusters are automatically upgraded to the next supported version seven days after notification for minor versions and one month after notification for major versions. Deprecated major versions are going to be upgraded even if you have disabled automatic updates.

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

In Yandex StoreDoc, the usage cost is calculated based on the following:

• 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 based on the pricing policy.
• Database host uptime in hours. Partial hours are rounded up to the nearest whole hour. You can find the cost per hour for each host class in the Pricing policy section.

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 from the management console. All you need to do is choose a different host class for the required cluster.

The cluster settings update within 30 minutes. This period may also include other cluster maintenance activities, such as installing updates.

Is database host backup enabled by default?Is database host backup enabled by default?

Yes, backup is enabled by default. For Yandex StoreDoc, a full backup is performed once a day with the possibility to restore it to any saved backup.

By default, backups are stored for seven days.

When are backups created? Is a database cluster available during backup?When are backups created? Is a database cluster available during backup?

The backup window is an interval during which a full daily backup of the DB cluster is performed. The backup window is from 01:00 to 05:00 (UTC+3).

Clusters remain fully accessible during the backup window.

Can I change the retention period for automatic backups?Can I change the retention period for automatic backups?

You can set the retention period for automatic backups when creating or modifying a cluster.

What metrics and processes can be monitored?What metrics and processes can be monitored?

For all DBMS types, you can monitor:

• CPU, memory, network, or disk usage, in absolute terms.
• Memory, network, and disk usage as a percentage of the set limits for the relevant cluster host class.
• Amount of data in a DB cluster and the remaining free space in your data storage.

For DB hosts, you can monitor metrics specific to their type of DBMS. For example, for Yandex StoreDoc, you can track:

• Number of queries per second.
• Disk space used.
• Number of connections, etc.

Monitoring can be performed with a minimum granularity of five seconds.

How do I set up an alert that triggers as soon as a certain percentage of disk space has been used up?How do I set up an alert that triggers as soon as a certain percentage of disk space has been used up?

Create an alert with the disk.used_bytes metric in Yandex Monitoring. This metric shows the disk space usage in the Yandex StoreDoc cluster.

For disk.used_bytes, use notification thresholds. The recommended values are as follows:

• Alarm: 90% of disk space
• Warning: 70% of disk space

Thresholds are set in bytes only. For example, the recommended values for a 100 GB disk are as follows:

• Alarm: 96636764160 bytes (90%)
• Warning: 75161927680 bytes (70%)

Questions about Yandex StoreDocQuestions about Yandex StoreDoc

Why should I use Yandex StoreDoc in Yandex StoreDoc rather than my own VM-based installation?Why should I use Yandex StoreDoc in Yandex StoreDoc rather than my own VM-based installation?

Yandex StoreDoc automates routine database maintenance:

• Quick DB deployment with the required available resources.
• Data backup.
• Regular software updates.
• Ensuring DB cluster fault tolerance.
• Database usage monitoring and statistics.

What happens to a cluster if one of its hosts fails?What happens to a cluster if one of its hosts fails?

If there are more than one replica in the database cluster, it will continue working if a host fails.

The only way data may be lost is if the cluster's only host fails.

Can I deploy a Yandex StoreDoc cluster in multiple availability zones?Can I deploy a Yandex StoreDoc cluster in multiple availability zones?

Yes. A database cluster may consist of hosts that reside in different availability zones and even different availability regions.

What is the backup procedure for Yandex StoreDoc clusters?What is the backup procedure for Yandex StoreDoc clusters?

Backups are created every 24 hours and retained for seven days. You can only restore data as of the backup creation time.

How does replication work for Yandex StoreDoc?How does replication work for Yandex StoreDoc?

Yandex StoreDoc uses the standard Yandex StoreDoc replication mechanism: if a cluster has more than one active host, one of them is automatically selected as the primary server to handle write requests.

What limitations are there for Yandex StoreDoc database clusters?What limitations are there for Yandex StoreDoc database clusters?

For more info on limitations in Yandex StoreDoc, see the Quotas and limits section.

Why is my cluster slow even though there are still some computing resources to spare?Why is my cluster slow even though there are still some computing resources to spare?

Your storage may have insufficient maximum IOPS and bandwidth to process the current number of requests. In this case, throttling occurs, which degrades the entire cluster performance.

The maximum IOPS and bandwidth values increase by a fixed value when the storage size increases by a certain step. The step and increment values depend on the disk type:

To increase the maximum IOPS and bandwidth values and make throttling less likely, increase the storage size when updating your cluster.

If you are using the network-hdd storage type, consider switching to network-ssd or network-ssd-nonreplicated by restoring the cluster from a backup.

How do I get access to the local.oplog.rs service collection?How do I get access to the local.oplog.rs service collection?

To grant a user read access to oplog, assign them the mdbReplication role in the admin database. Do it by executing the following command in the Yandex Cloud CLI:

yc managed-mongodb user update <username> \
  --cluster-name <cluster_name> \
  --permission database=admin,role=mdbReplication,role=<other_role>,... \
  --permission database=<other_DB_name>,role=<role>,...

To avoid deleting user roles that are already assigned, list both the existing and new roles in the command.

Can I connect to cluster hosts over SSH or get superuser privileges on hosts?Can I connect to cluster hosts over SSH or get superuser privileges on hosts?

You cannot connect to hosts via SSH. This is done for the sake of security and user cluster fault tolerance because direct changes inside a host can render it completely inoperable.

What should I do if I get a revocation check error when using PowerShell to obtain an SSL certificate?What should I do if I get a revocation check error when using PowerShell to obtain an SSL certificate?

Here is the full text of the error:

curl: (35) schannel: next InitializeSecurityContext failed: Unknown error (0x80092012)
The revocation function was unable to check revocation for the certificate

This means, when connecting to the website, the service was unable to check whether or not its certificate was listed among revoked ones.

To fix this error:

• Make sure the corporate network settings do not block the check.

• Run the following command with the --ssl-no-revoke parameter:

   mkdir $HOME\.mongodb; curl.exe --ssl-no-revoke -o $HOME\.mongodb\root.crt https://storage.yandexcloud.net/cloud-certs/CA.pem