TiDB Cloud Serverless Limitations and Quotas

TiDB Cloud Serverless works with almost all workloads that TiDB supports, but there are some feature differences between TiDB Self-Managed or TiDB Cloud Dedicated clusters and TiDB Cloud Serverless clusters. This document describes the limitations of TiDB Cloud Serverless.

We are constantly filling in the feature gaps between TiDB Cloud Serverless and TiDB Cloud Dedicated. If you require these features or capabilities in the gap, use TiDB Cloud Dedicated or contact us for a feature request.

Limitations

Audit logs

Database audit logging is currently unavailable.

Connection

Only Public Endpoint and Private Endpoint can be used. You cannot use VPC Peering to connect to TiDB Cloud Serverless clusters.
No IP Access list support.

Encryption

Data persisted in your TiDB Cloud Serverless cluster is encrypted using the encryption tool provided by the cloud provider that manages your cluster. However, TiDB Cloud Serverless does not provide any additional optional measures for protecting data at-rest on disks beyond infrastructure-level encryption.
Using customer-managed encryption keys (CMEK) is currently unavailable.

Maintenance window

Maintenance window is currently unavailable.

Monitoring and diagnosis

Third-party Monitoring integrations are currently unavailable.
Built-in Alerting is currently unavailable.
Key Visualizer is currently unavailable.
Index Insight is currently unavailable.

Self-service upgrades

TiDB Cloud Serverless is a fully managed deployment of TiDB. Major and minor version upgrades of TiDB Cloud Serverless are handled by TiDB Cloud and therefore cannot be initiated by users.

Stream data

Changefeed is not supported for TiDB Cloud Serverless currently.
Data Migration is not supported for TiDB Cloud Serverless currently.

Time to live (TTL)

In TiDB Cloud Serverless, the TTL_JOB_INTERVAL attribute for a table is fixed at 15m and cannot be modified. This means that TiDB Cloud Serverless schedules a background job every 15 minutes to clean up expired data.

Others

Transaction can not last longer than 30 minutes.
For more details about SQL limitations, refer to Limited SQL Features.

Usage quota

For each organization in TiDB Cloud, you can create a maximum of five free clusters by default. To create more TiDB Cloud Serverless clusters, you need to add a credit card and create scalable clusters for the usage.

For the first five TiDB Cloud Serverless clusters in your organization, whether they are free or scalable, TiDB Cloud provides a free usage quota for each of them as follows:

Row-based storage: 5 GiB
Columnar storage: 5 GiB
Request Units (RUs): 50 million RUs per month

The Request Unit (RU) is a unit of measurement used to track the resource consumption of a query or transaction. It is a metric that allows you to estimate the computational resources required to process a specific request in the database. The request unit is also the billing unit for TiDB Cloud Serverless service.

Once a cluster reaches its usage quota, it immediately denies any new connection attempts until you increase the quota or the usage is reset upon the start of a new month. Existing connections established before reaching the quota will remain active but will experience throttling.

To learn more about the RU consumption of different resources (including read, write, SQL CPU, and network egress), the pricing details, and the throttled information, see TiDB Cloud Serverless Pricing Details.

If you want to create a TiDB Cloud Serverless cluster with an additional quota, you can select the scalable cluster plan and edit the spending limit on the cluster creation page. For more information, see Create a TiDB Cloud Serverless cluster.

After creating a TiDB Cloud Serverless cluster, you can still check and edit the spending limit on your cluster overview page. For more information, see Manage Spending Limit for TiDB Cloud Serverless Clusters.