PolarDB for MySQL provides storage plans to reduce the storage costs of your clusters.
Storage plans
The storage capacity of PolarDB for MySQL is automatically scaled based on the amount of stored data. You do not need to manually specify the storage capacity. Fees are charged only for the used storage. The storage of each PolarDB for MySQL cluster is charged based on the data volume and retention period. If you require a larger storage capacity, such as 1,000 GB or more, we recommend that you purchase storage plans to reduce costs.
A storage plan is a subscription-based resource plan provided by PolarDB. You can use storage plans to offset fees for storage, level-1 backups that exceed the free quota, level-2 backups, log backups, and cold data storage. Storage plans can effectively reduce the costs, and the larger the specifications of the storage plans (capacity and duration), the more costs you save.
For example, a monthly storage plan costs 10% to 45% less than using the pay-as-you-go method for the storage of a cluster. The longer the duration of the storage plan, the higher the cost reduction. If you purchase annual storage plans, you can save an additional 15% off the monthly price.
Applicable storage and offset rules
A storage plan can offset the storage usage that uses the pay-as-you-go billing method, level-1 backups that exceed the free quota, level-2 backups, log backups, and cold data archiving.
For the storage that uses the pay-as-you-go billing method of a PolarDB Enterprise Edition cluster.
NoteStorage plans can offset only the storage that uses the pay-as-you-go billing method and cannot offset storage that uses the subscription billing method.
After your storage plans are exhausted, you are charged for the excess storage on a pay-as-you-go basis.
Storage type
Offset ratio
The storage capacity that is offset by every 1 GB of storage plan (Regions in the Chinese mainland)
The storage capacity that is offset by every 1 GB of storage plan (Regions outside the Chinese mainland)
PSL4 (Hot standby storage cluster enabled)
0.65
1.54 GB
1.54 GB
PSL4 (Hot standby storage cluster disabled)
0.325
3.08 GB
3.08 GB
PSL5 (Hot standby storage cluster enabled)
1
1 GB
1 GB
PSL5 (Hot standby storage cluster disabled)
0.5
2 GB
2 GB
For example, for a PSL4 cluster in a region of the Chinese mainland with hot standby storage cluster enabled, a 50-GB storage plan can be used to deduct a storage capacity of 76.92 GB (1/0.65 × 50). Excess storage usage over 76.92 GB is charged on a pay-as-you-go basis.
For the level-1 backups that exceeds the free quota of a PolarDB Enterprise Edition cluster.
Region type
Offset ratio
The level-1 backup storage that is offset by every 1 GB of storage plan
Regions in the Chinese mainland (PSL4)
0.41
1/0.41=2.44 GB
Regions in the Chinese mainland (PSL5)
0.617
1/0.617=1.62 GB
Regions outside the Chinese mainland (PSL4)
0.41
1/0.41=2.44 GB
Regions outside the Chinese mainland (PSL5)
0.617
1/0.617=1.62 GB
For example, you purchase a storage plan with a capacity of 100 GB and 50 GB is left after you offset the storage space (PSL5). Your cluster uses 50 GB of storage for level-1 backups (outside the free quota) in a Chinese mainland region. In this case, the storage plan automatically uses 31.25 GB (50/1.6=31.25) to offset the backup storage. As a result, the storage plan has 18.75 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the level-1 backups, you are charged for the excess storage usage on a pay-as-you-go basis.
For the level-2 backups of a PolarDB Enterprise Edition cluster.
Region type
Offset ratio
The level-2 backup storage that is offset by every 1 GB of storage plan
Regions in the Chinese mainland
0.043
1/0.043=23.26 GB
Regions outside the Chinese mainland
0.054
1/0.054=18.52 GB
For example, you purchase a storage plan with a capacity of 100 GB, and 50 GB is left after it offsets the data storage usage. Your cluster uses 50 GB of storage for level-2 backups in a Chinese mainland region. In this case, the storage plan automatically uses 2.15 GB (50/23.26) to offset the backup storage usage and the storage plan has 47.85 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the level-2 backups, you are charged for the excess storage usage on a pay-as-you-go basis.
For the log backups of a PolarDB Enterprise Edition cluster.
Region type
Offset ratio
The log backup storage that is offset by every 1 GB of storage plan
Regions in the Chinese mainland
0.043
1/0.043=23.26 GB
Regions outside the Chinese mainland
0.054
1/0.054=18.52 GB
For example, you purchase a storage plan with a capacity of 100 GB, and 50 GB is left after it offsets the data storage usage. Your cluster uses 50 GB of storage for log backups in a Chinese mainland region. In this case, the storage plan automatically uses 2.15 GB (50/23.26) to offset the backup storage usage and the storage plan has 47.85 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the log backups, you are charged for the excess storage usage on a pay-as-you-go basis.
For the OSS storage usage for cold data archiving of a PolarDB Enterprise Edition cluster.
Region type
Offset ratio
The OSS storage that is offset by every 1 GB of storage plan
Regions in the Chinese mainland
0.045
1/0.045=22.22 GB
Regions outside the Chinese mainland
0.045
1/0.045=22.22 GB
For example, you purchase a storage plan with a capacity of 100 GB, and 50 GB is left after it offsets the data storage usage. The cold data of your cluster occupies 50 GB of OSS storage space in a Chinese mainland region. In this case, the storage plan automatically uses 2.25 GB (50/22.22) to offset the backup usage of the cold data and the storage plan has 47.75 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the cold data storage, you are charged for additional storage space on a pay-as-you-go basis.
Offset order
Storage spaces are offset based on the following order:
PolarDB Enterprise Edition: Cluster storage usage (PSL5 and PSL4)> Level-1 backups that exceed the free quota> OSS cold data archiving> Level-2 backups> Log backups. If multiple clusters are of the same priority, the clusters are ordered based on the time at which they were created. The clusters that are created earlier take precedence.
Apply storage plans
PolarDB provides two billing methods for compute nodes: pay-as-you-go and subscription. The pricing of clusters varies based on the billing method used. For more information about how to apply storage plans to compute nodes that use these two billing methods, see the following topics:
Pricing of storage plans
This section describes the price comparison of different offset capacity under the two purchase schemes of unused storage plans and monthly storage plans.
Capacity (GB) | Regions in the Chinese mainland (USD/month) (1.7% to 47.0% lower compared with when storage plans are not used) | Regions outside the Chinese mainland (USD/month) (1.6% to 46.6% lower compared with when storage plans are not used) |
50 | 28 (No discount) | 31 (No discount) |
100 | 55 (approximately 1.7% off) | 61 (approximately 1.6% off) |
200 | 109 (approximately 2.7% off) | 121 (approximately 2.4% off) |
300 | 163 (approximately 3% off) | 182 (approximately 2.6% off) |
500 | 271 (approximately 3.2% off) | 302 (approximately 2.6% off) |
1,000 | 490 (approximately 12.5% off) | 550 (approximately 11.3% off) |
2,000 | 980 (approximately 12.5% off) | 1,090 (approximately 12.1% off) |
3,000 | 1,210 (approximately 28.0% off) | 1,340 (approximately 28.0% off) |
5,000 | 2,020 (approximately 28.0% off) | 2,230 (approximately 28.1% off) |
10,000 | 3,260 (approximately 41.8% off) | 3,630 (approximately 41.5% off) |
20,000 | 6,510 (approximately 41.9% off) | 7,250 (approximately 41.5% off) |
30,000 | 9,760 (approximately 42.0% off) | 10,870 (approximately 41.5% off) |
50,000 | 14,860 (approximately 47.0% off) | 16,550 (approximately 46.6% off) |
100,000 | 29,720 (approximately 47.0% off) | 33,110 (approximately 46.6% off) |
200,000 | 59,440 (approximately 47.0% off) | 66,220 (approximately 46.6% off) |
Purchase a storage plan
For more information about storage plans and how to purchase storage plans, see Purchase a storage plan.
- Storage plans can be used by all PolarDB for MySQL clusters in the regions that are specified by the Plan Type parameter. You can select Chinese Mainland or Outside Chinese Mainland.
- If the capacity of your storage plan is insufficient, you can purchase an additional storage plan or upgrade the storage plan. However, storage plans cannot be downgraded.
- If the amount of used storage exceeds the capacity of your storage plan, you are charged for the additional storage resources based on the pay-as-you-go billing method.
For example, assume that you have created three PolarDB for MySQL clusters that each requires 400 GB of storage. If you purchase a storage plan of 1,000 GB and these clusters share the storage plan, the storage resources used in excess of 200 GB are billed on a pay-as-you-go basis. For more information, see View the database storage usage.