Yandex Managed Service for Valkey™ storage

Yandex Managed Service for Valkey™ allows you to use network and local storage drives for database clusters. Network drives are based on network blocks, which are virtual disks in the Yandex Cloud infrastructure. Local disks are physically located on the database host servers.

When creating a cluster, you can select the following disk types for data storage:

• Network SSDs (network-ssd): Balanced solution. Such disks are slower than local SSD storage, but, unlike local disks, they ensure data integrity if Yandex Cloud hardware fails.

• Non-replicated SSDs (network-ssd-nonreplicated): Network SSDs with enhanced performance achieved by eliminating redundancy.

  This disk type is only available for Intel Cascade Lake and Intel Ice Lake. For a list of host classes and their respective platforms, see Valkey™ host classes.

  The storage size can only be increased in 93 GB increments.

• Ultra high-speed network SSDs with three replicas (network-ssd-io-m3): Network disks with the same performance characteristics as non-replicated ones. This disk type provides redundancy.

  Such disks can be increased in size only in 93 GB increments.

• Local SSDs (local-ssd): Disks with the best performance.

  The size of such a storage can be increased:

  • For Intel Broadwell and Intel Cascade Lake: Only in 100 GB increments.
  • For Intel Ice Lake: In 368 GB increments only.

  For a list of host classes and their respective platforms, see Valkey™ host classes.

  For clusters with hosts residing in the ru-central1-d availability zone, local SSD storage is not available if using Intel Cascade Lake.

Selecting disk type when creating a clusterSelecting disk type when creating a cluster

The number of hosts you can create together with a Valkey™ cluster depends on the disk type you select and whether you enabled sharding:

Sharded clusters with the local-ssd disk type and only one host per shard are not considered fault-tolerant. You cannot create such a cluster.

For more information about limits on the number of hosts per cluster or shard, see Quotas and limits.

Disk space managementDisk space management

When the storage is 100% full, cluster hosts automatically switch to read-only mode. In this mode, data write requests fail. To release the cluster from read-only mode, increase the storage size or contact support.

Monitoring the transition to read-only modeMonitoring the transition to read-only mode

To monitor the cluster storage utilization percentage, set up alerts in Yandex Monitoring:

1. Navigate to the folder dashboard and select Monitoring.

2. Create a notification channel.

3. Create an alert with the following properties:

4. Metrics: Set the following metric parameters:

   • Cloud.
   • Folder.
   • Yandex Managed Service for Valkey™.
   • disk.free_bytes label.
   • Yandex Managed Service for Valkey™ cluster of interest. You can get the cluster name and ID with the list of clusters in the folder.

5. Alert condition: Set the condition for free disk space usage to trigger the alert:

   • Aggregation function: Minimum (minimum metric value for the period).
   • Comparison function: Less than or equals.
   • Warning: 90 (90 % of storage size).
   • Alarm: 95 (95 % of storage size).
   • Evaluation window: Preferred metric update period.
   • Evaluation delay: Preferred time shift backward, in seconds. It allows to keep the alert from triggering when multiple metrics are specified and collected at different intervals. To learn more about the calculation delay, see this Yandex Monitoring guide.

6. Notifications: Add the previously created notification channel.

Automatic increase of storage sizeAutomatic increase of storage size

Automatic increase of storage size prevents situations where free disk space has been used up and hosts have switched to read-only mode. The storage size increases upon reaching the specified threshold percentage of the total capacity. There are two thresholds:

• Scheduled increase threshold: When reached, the storage size increases during the next maintenance window. If this threshold is set, configure the maintenance schedule.
• Immediate increase threshold: When reached, the storage size increases immediately.

You can use either one or both thresholds. If you set both, make sure the immediate increase threshold is higher than the scheduled one.

If the specified threshold is reached, the storage size increases differently depending on disk type:

• For network SSDs, by the higher of the two values: 20 GB or 20% of the current disk size.

• For non-replicated SSDs and ultra high-speed network SSDs with three replicas, by 93 GB.

• For local SSDs:

  • Intel Broadwell and Intel Cascade Lake, by 100 GB.
  • Intel Ice Lake, by 368 GB.

If the threshold is reached again, the storage size will be automatically increased until it reaches the specified maximum. After that, you can specify a new maximum storage size manually.

You can configure automatic increase of storage size when creating or updating a cluster.

Disk encryptionDisk encryption

When creating or restoring a cluster from a backup, you can encrypt the storage disk with a custom KMS key. To encrypt a disk of an already created cluster, disable encryption, or encrypt a disk with a different key, create a backup of the cluster and restore it with the new settings.

To create an encrypted disk, you need the kms.keys.user role or higher.

If you deactivate the key used to encrypt a disk, access to the data will be suspended until you reactivate the key.

Use casesUse cases

• Using a Yandex Managed Service for Valkey™ cluster as a PHP session storage
• Migrating a database from a third-party Valkey™ cluster