--- title: Limitations and Quotas of TiDB Cloud Starter and Essential summary: Learn about the limitations of TiDB Cloud Starter. aliases: ['/tidbcloud/serverless-tier-limitations'] --- # Limitations and Quotas of TiDB Cloud Starter and Essential TiDB Cloud Starter and Essential work with almost all workloads that TiDB supports, but there are some feature differences compared with TiDB Self-Managed or TiDB Cloud Dedicated clusters. This document describes the limitations of TiDB Cloud Starter and TiDB Cloud Essential. We are constantly filling in the feature gaps between TiDB Cloud Starter/Essential and TiDB Cloud Dedicated. If you require these features or capabilities in the gap, use [TiDB Cloud Dedicated](/tidb-cloud/select-cluster-tier.md#tidb-cloud-dedicated) or [contact us](https://www.pingcap.com/contact-us/?from=en) for a feature request. ## Limitations ### Audit logs - [Database audit logging](/tidb-cloud/essential-database-audit-logging.md) is currently unavailable for TiDB Cloud Starter clusters. ### Connection - Only [Public Endpoint](/tidb-cloud/connect-via-standard-connection-serverless.md) and [Private Endpoint](/tidb-cloud/set-up-private-endpoint-connections-serverless.md) can be used. You cannot use [VPC Peering](/tidb-cloud/set-up-vpc-peering-connections.md) to connect to TiDB Cloud Starter or TiDB Cloud Essential clusters. - No [Firewall Rules](/tidb-cloud/configure-serverless-firewall-rules-for-public-endpoints.md) support for Private Endpoint. - Your database client connections might be terminated unexpectedly if they remain open for more than 30 minutes. This can occur when a TiDB server shuts down, restarts, or undergoes maintenance, potentially causing application disruptions. To avoid this issue, configure a maximum connection lifetime. It is recommended to start with 5 minutes and increase it gradually if it affects tail latency. For more information, see [Recommended settings for connection pools](/develop/dev-guide-connection-parameters.md#connection-pools-and-connection-parameters). > **Note:** > > Due to a [limitation of AWS Global Accelerator](https://docs.aws.amazon.com/global-accelerator/latest/dg/introduction-how-it-works.html#about-idle-timeout), the idle timeout for a Public Endpoint connection on AWS is 340 seconds. For the same reason, you cannot use TCP keep-alive packets to keep the connection open. ### Encryption - Data persisted in your TiDB Cloud Starter or TiDB Cloud Essential cluster is encrypted using the encryption tool provided by the cloud provider that manages your cluster. For TiDB Cloud Starter (with spending limit > 0) and TiDB Cloud Essential clusters, an optional second layer of encryption is available during the cluster creation process, providing an additional level of security beyond the default encryption at rest. - Using [customer-managed encryption keys (CMEK)](/tidb-cloud/tidb-cloud-encrypt-cmek-aws.md) is currently unavailable. ### Maintenance window - [Maintenance window](/tidb-cloud/configure-maintenance-window.md) is currently unavailable. ### Monitoring and diagnosis - [Third-party Monitoring integrations](/tidb-cloud/third-party-monitoring-integrations.md) are currently unavailable. - [Built-in Alerting](/tidb-cloud/monitor-built-in-alerting.md) is currently unavailable. - [Key Visualizer](/tidb-cloud/tune-performance.md#key-visualizer) is currently unavailable. ### Self-service upgrades - TiDB Cloud Starter and TiDB Cloud Essential are fully managed deployments of TiDB. Major and minor version upgrades of TiDB Cloud Starter and TiDB Cloud Essential are handled by TiDB Cloud and therefore cannot be initiated by users. ### Stream data - [Changefeed](/tidb-cloud/changefeed-overview.md) is not supported for TiDB Cloud Starter and TiDB Cloud Essential currently. - [Data Migration](/tidb-cloud/migrate-from-mysql-using-data-migration.md) is not supported for TiDB Cloud Starter and TiDB Cloud Essential currently. ### Time to live (TTL) - In TiDB Cloud Starter and TiDB Cloud Essential, the [`TTL_JOB_INTERVAL`](/time-to-live.md#ttl-job) attribute for a table is fixed at `15m` and cannot be modified. This means that TiDB Cloud Starter and TiDB Cloud Essential schedule 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](/tidb-cloud/limited-sql-features.md). ## Usage quota For each organization in TiDB Cloud, you can create a maximum of five [free TiDB Cloud Starter clusters](/tidb-cloud/select-cluster-tier.md#starter) by default. To create more TiDB Cloud Starter clusters, you need to add a credit card and [set a monthly spending limit](/tidb-cloud/manage-serverless-spend-limit.md) for the usage. For the first five TiDB Cloud Starter clusters in your organization, 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)](/tidb-cloud/tidb-cloud-glossary.md#request-unit-ru): 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 Starter service. Once a cluster reaches its usage quota, it immediately denies any new connection attempts until you [increase the quota](/tidb-cloud/manage-serverless-spend-limit.md#update-spending-limit) 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 Starter Pricing Details](https://www.pingcap.com/tidb-cloud-starter-pricing-details/). If you want to create a TiDB Cloud Starter cluster with an additional quota, you can set the monthly spending limit on the cluster creation page. For more information, see [Create a TiDB Cloud Starter cluster](/tidb-cloud/create-tidb-cluster-serverless.md). After creating a TiDB Cloud Starter 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 Starter Clusters](/tidb-cloud/manage-serverless-spend-limit.md).