What are the billable items and billing rules when you use the serverless feature of PolarDB for MySQL - PolarDB

This topic describes the billable items and billing rules of the serverless feature provided by PolarDB for MySQL.

Billable items

Note

The fees of a serverless-enabled cluster with defined specifications include the fees of the common cluster with defined specifications and the serverless feature. For more information about the fees of a common cluster with defined specifications, see Billable items.

Billable item	Description
Compute nodes	Serverless compute nodes include the primary node and read-only nodes. Serverless compute nodes are scaled in units of 0.5 PolarDB Capacity Units (PCUs). The billing duration is accurate to the second, and bills are generated per hour based on PCUs. The hourly bill is calculated by using the following formula: (Sum of PCUs per second/3600) × Hourly price of PCUs The bill of a compute node depends on the region where the node is deployed and the usage duration.
Storage space	Storage space is used to store cluster data files, index files, log files, and temporary files. Log files include online and archived logs. You are charged for the amount of storage space that you use. The storage space amount for which you are charged depends on the volume of stored data and the length of time for which the data is retained. Note Fees for serverless storage usage can be offset by storage plans. For more information about billing rules, see What are storage plans.
Backup storage space (only charged after the free quota is reached)	Backup files consume storage space. PolarDB provides a free storage quota for backup files. If the actual storage capacity that you use exceeds the quota, you are charged for the excess storage capacity consumed by backup files. The backup storage amount for which you are charged depends on the size of data backup files and the length of time for which the files are retained.
SQL Explorer (optional)	The SQL Explorer feature provides value-added capabilities, such as security auditing and performance diagnostics. After you enable this feature, you are charged for the amount of storage space consumed by audit logs. The storage space amount for which you are charged depends on the size of audit logs and the length of time for which the logs are retained.

Note

If the serverless feature runs as expected, you are charged for the preceding billable items.
If the serverless feature becomes unavailable, you are not charged for compute nodes. However, you are charged for storage space, backup storage space, and SQL Explorer (optional).

Billing rules

Compute nodes

Compute nodes are billed in PCUs. One PCU is approximately equal to 1 core and 2 GB of memory and 0.5 PCUs are approximately equal to 0.5 cores and 1 GB of memory. Compute nodes are scaled in units of 0.5 PCUs. If more current PCUs are used by a node, more PCUs are added or removed in the scaling. Compute nodes are billed on an hourly basis. The following table describes the billing details.

Table 2. Hourly prices of a pay-as-you-go PCU
Billable item	Regions in the Chinese mainland	US (Silicon Valley)	Indonesia (Jakarta)	Germany (Frankfurt)	India (Mumbai)	US (Virginia)	Japan (Tokyo)	Philippines (Manila)	Thailand (Bangkok)	South Korea (Seoul)	Singapore	Malaysia (Kuala Lumpur)	China (Hong Kong)	UK (London)	Australia (Sydney)
Compute nodes	USD 0.0611	USD 0.0947	USD 0.1069	USD 0.1038	USD 0.0916	USD 0.0794	USD 0.0977	USD 0.1069	USD 0.1069	USD 0.0977	USD 0.1160	USD 0.1160	USD 0.1160	USD 0.1160	USD 0.1160

The hourly fees of compute nodes are calculated by using the following formula: [Unit price of PCUs × (Minimum number of read-only nodes + 1 primary node) × Minimum number of PCUs per node] to [Unit price of PCUs × (Maximum number of read-only nodes + 1 primary node) × Maximum number of PCUs per node].

Storage space

For serverless clusters, a serverless architecture is used for storage. Therefore, you do not need to specify the storage capacity when you purchase clusters. The storage capacity is automatically increased when the amount of data increases. You are charged only for the storage that you use. For more information about billing rules, see Pay-as-you-go.
For serverless-enabled clusters with defined specifications, the storage space uses the storage of common clusters with defined specifications. For more information about billing rules, see Pay-as-you-go and Subscription.

Note

Fees for the usage of storage resources can be offset by storage plans. For more information about billing rules, see What are storage plans.

Backup storage space

The serverless feature supports level-1 backup, level -2 backup, and log backup. For more information about billing rules, see Billing rules for backup storage that exceeds the free quota.

️SQL Explorer

You are charged for SQL Explorer only after the SQL Explorer feature is enabled. For more information about how to enable SQL Explorer, see SQL Explorer and Audit. For more information about billing rules, see Billing rules of SQL Explorer (optional).