Root cause analysis scenario: Schema leak schema_leak

Applicable scenarios

This article is suitable for root cause analysis of Schema leak problems. It is based on the analysis of OceanBase database internal table data and logs to help locate the cause of Schema leaks.

Currently, OceanBase database V4.0.0.0 and later versions are supported. When using obdiag, you need to configure the cluster information in the ~/.obdiag/config.yml file according to your choice, or configure the cluster information through the --config option in the command.

Can import environment variables

Usage example

• Configure analysis scenarios, executed by default

  obdiag rca run --scene=schema_leak

• Configure the analysis scenario and specify the tenant ID

  obdiag rca run --scene=schema_leak --env tenant_id=1001

Analyze content

This scenario analyzes the following:

1. Schema version history: Check the history of Schema versions and analyze whether there is abnormal growth.
2. Schema refresh status: Analyze the status and frequency of Schema refresh.
3. Memory usage analysis: Check Schema-related memory usage.
4. Historical DDL operations: Analyze whether historical DDL operations cause Schema leaks.

Output results

After the analysis is completed, a diagnostic report will be generated, which includes:

• Root cause analysis results of Schema leaks
• Leak point location information
• Fix suggestions

Common reasons

Common causes of Schema leaks include:

• Frequent DDL operations lead to too many Schema versions.
• Schema refresh mechanism is abnormal.
• Long-running transactions prevent Schema recycling.
• Schema cannot be cleaned properly due to some bugs.

Solution suggestions

• Avoid too frequent DDL operations.
• Check for long-running transactions or sessions.
• If it is confirmed to be a bug, please upgrade to the fixed version or contact technical support.