- Release Notes and Announcements
- Release Notes
- Announcements
- Announcement on Optimization of Instance Storage Capacity, IOPS, and I/O Bandwidth
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Sales Suspension of Some General Specifications
- Announcement on Some APIs Integrated with CAM Authentication
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Change of Part of Parameters
- Announcement on Update of Database Audit Feature
- Announcement on Authentication of a Newly Added API Interface of Database Audit
- Announcement on Change of Public Network Linkage
- TDSQL-C for MySQL Audit Service Update
- Announcement on Supplementary Charge for Clusters with Pay-as-You-Go Storage Billing Mode
- Announcement on New APIs Integrated with CAM Permissions
- Announcement on the Release of New Version of Database Proxy
- Emergency Fix for Certain Monitoring Metrics
- Monitoring Metric Optimization
- Change to Database Audit Resource ID
- Ops Change
- Storage Price Adjustment Notification
- Product Introduction
- Kernel Features
- Purchase Guide
- Getting Started
- Database Audit
- Serverless Service
- Operation Guide
- Switching Cluster Page View in Console
- Database Connection
- Instance Management
- Configuration Adjustment
- Cluster Management
- Scaling Instance
- Database Proxy
- Database Proxy Overview
- Use Limits
- Database Proxy Kernel Features
- Managing Database Proxy
- Enabling Database Proxy
- Setting Database Proxy Address
- Modifying or Deleting Connection Addresses
- Viewing and Changing the Access Policy
- Rebalancing the Load
- Transaction Split Feature
- Access Mode
- Adjusting Database Proxy Configuration
- Switching Database Proxy Network
- Viewing Database Proxy Monitoring Data
- Disabling Database Proxy
- Automatic Read/Write Separation
- Connection Pool Feature
- Other Features
- Account Management
- Database Management
- Database Management Tool
- Columnar Storage Index (CSI)
- Parameter Configuration
- Multi-AZ Deployment
- Backup and Restoration
- Operation Log
- Data Migration
- Parallel Query
- Database Security and Encryption
- Monitoring and Alarms
- Basic SQL Operations
- Connecting to TDSQL-C for MySQL Through SCF
- Tag
- Practical Tutorial
- Classified Protection Practice for Database Audit of TDSQL-C for MySQL
- Upgrading Database Version from MySQL 5.7 to 8.0 Through DTS
- Usage Instructions for TDSQL-C MySQL
- New Version of Console
- Implementing Multiple RO Groups with Multiple Database Proxy Connection Addresses
- Strengths of Database Proxy
- Selecting Billing Mode for Storage Space
- Creating Remote Disaster Recovery by DTS
- Creating VPC for Cluster
- Data Rollback
- Solution to High CPU Utilization
- How to Authorize Sub-Users to View Monitoring Data
- White Paper
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- Billing APIs
- Instance APIs
- CloseClusterPasswordComplexity
- CopyClusterPasswordComplexity
- DescribeClusterDetail
- DescribeClusterPasswordComplexity
- ModifyClusterPasswordComplexity
- OpenClusterPasswordComplexity
- UpgradeClusterVersion
- UpgradeInstance
- SetRenewFlag
- OfflineCluster
- ModifyMaintainPeriodConfig
- IsolateInstance
- IsolateCluster
- DescribeMaintainPeriod
- DescribeInstanceSpecs
- DescribeClusters
- CreateClusters
- AddInstances
- OfflineInstance
- DescribeInstanceDetail
- DescribeClusterInstanceGrps
- DescribeInstances
- ActivateInstance
- ModifyInstanceName
- ModifyClusterName
- SearchClusterTables
- SearchClusterDatabases
- RestartInstance
- Multi-AZ APIs
- Account APIs
- Audit APIs
- Database Proxy APIs
- Backup and Restoration APIs
- Parameter Management APIs
- Performance Analysis APIs
- Serverless APIs
- ResourcePackage APIs
- Other APIs
- CloseWan
- CreateClusterDatabase
- DeleteClusterDatabase
- DescribeClusterDetailDatabases
- ModifyClusterDatabase
- OpenWan
- SwitchClusterVpc
- OpenReadOnlyInstanceExclusiveAccess
- OpenClusterReadOnlyInstanceGroupAccess
- ModifyDBInstanceSecurityGroups
- DescribeProjectSecurityGroups
- DescribeDBSecurityGroups
- SwitchProxyVpc
- DescribeFlow
- DescribeZones
- ModifyVipVport
- Data Types
- Error Codes
- FAQs
- Service Agreement
- TDSQL-C Policy
- General References
- Glossary
- Contact Us
- Release Notes and Announcements
- Release Notes
- Announcements
- Announcement on Optimization of Instance Storage Capacity, IOPS, and I/O Bandwidth
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Sales Suspension of Some General Specifications
- Announcement on Some APIs Integrated with CAM Authentication
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Change of Part of Parameters
- Announcement on Update of Database Audit Feature
- Announcement on Authentication of a Newly Added API Interface of Database Audit
- Announcement on Change of Public Network Linkage
- TDSQL-C for MySQL Audit Service Update
- Announcement on Supplementary Charge for Clusters with Pay-as-You-Go Storage Billing Mode
- Announcement on New APIs Integrated with CAM Permissions
- Announcement on the Release of New Version of Database Proxy
- Emergency Fix for Certain Monitoring Metrics
- Monitoring Metric Optimization
- Change to Database Audit Resource ID
- Ops Change
- Storage Price Adjustment Notification
- Product Introduction
- Kernel Features
- Purchase Guide
- Getting Started
- Database Audit
- Serverless Service
- Operation Guide
- Switching Cluster Page View in Console
- Database Connection
- Instance Management
- Configuration Adjustment
- Cluster Management
- Scaling Instance
- Database Proxy
- Database Proxy Overview
- Use Limits
- Database Proxy Kernel Features
- Managing Database Proxy
- Enabling Database Proxy
- Setting Database Proxy Address
- Modifying or Deleting Connection Addresses
- Viewing and Changing the Access Policy
- Rebalancing the Load
- Transaction Split Feature
- Access Mode
- Adjusting Database Proxy Configuration
- Switching Database Proxy Network
- Viewing Database Proxy Monitoring Data
- Disabling Database Proxy
- Automatic Read/Write Separation
- Connection Pool Feature
- Other Features
- Account Management
- Database Management
- Database Management Tool
- Columnar Storage Index (CSI)
- Parameter Configuration
- Multi-AZ Deployment
- Backup and Restoration
- Operation Log
- Data Migration
- Parallel Query
- Database Security and Encryption
- Monitoring and Alarms
- Basic SQL Operations
- Connecting to TDSQL-C for MySQL Through SCF
- Tag
- Practical Tutorial
- Classified Protection Practice for Database Audit of TDSQL-C for MySQL
- Upgrading Database Version from MySQL 5.7 to 8.0 Through DTS
- Usage Instructions for TDSQL-C MySQL
- New Version of Console
- Implementing Multiple RO Groups with Multiple Database Proxy Connection Addresses
- Strengths of Database Proxy
- Selecting Billing Mode for Storage Space
- Creating Remote Disaster Recovery by DTS
- Creating VPC for Cluster
- Data Rollback
- Solution to High CPU Utilization
- How to Authorize Sub-Users to View Monitoring Data
- White Paper
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- Billing APIs
- Instance APIs
- CloseClusterPasswordComplexity
- CopyClusterPasswordComplexity
- DescribeClusterDetail
- DescribeClusterPasswordComplexity
- ModifyClusterPasswordComplexity
- OpenClusterPasswordComplexity
- UpgradeClusterVersion
- UpgradeInstance
- SetRenewFlag
- OfflineCluster
- ModifyMaintainPeriodConfig
- IsolateInstance
- IsolateCluster
- DescribeMaintainPeriod
- DescribeInstanceSpecs
- DescribeClusters
- CreateClusters
- AddInstances
- OfflineInstance
- DescribeInstanceDetail
- DescribeClusterInstanceGrps
- DescribeInstances
- ActivateInstance
- ModifyInstanceName
- ModifyClusterName
- SearchClusterTables
- SearchClusterDatabases
- RestartInstance
- Multi-AZ APIs
- Account APIs
- Audit APIs
- Database Proxy APIs
- Backup and Restoration APIs
- Parameter Management APIs
- Performance Analysis APIs
- Serverless APIs
- ResourcePackage APIs
- Other APIs
- CloseWan
- CreateClusterDatabase
- DeleteClusterDatabase
- DescribeClusterDetailDatabases
- ModifyClusterDatabase
- OpenWan
- SwitchClusterVpc
- OpenReadOnlyInstanceExclusiveAccess
- OpenClusterReadOnlyInstanceGroupAccess
- ModifyDBInstanceSecurityGroups
- DescribeProjectSecurityGroups
- DescribeDBSecurityGroups
- SwitchProxyVpc
- DescribeFlow
- DescribeZones
- ModifyVipVport
- Data Types
- Error Codes
- FAQs
- Service Agreement
- TDSQL-C Policy
- General References
- Glossary
- Contact Us
Feature Overview
During execution of a DML statement, if a metadata lock (MDL) is held, it will block DDL operations for the corresponding table and then block all subsequent DML statements, possibly consuming a large amount of thread resources. To prevent this case, TDSQL-C for MySQL introduces a Nonblocking DDL mechanism, protecting the system from being stalled by DDL operations waiting for MDL locks. When a DDL operation is blocked by a DML statement, subsequent DML statements will not further get blocked due to waiting for an MDL lock.
Supported Versions
The kernel version should be 3.1.15 or later for TXSQL 8.0.
Applicable Scenarios
It is applicable to scenarios where an MDL lock held during execution of a DML statement may block DDL operations for the corresponding table and then block all subsequent DML statements.
Use Instructions
Parameter Name | Dynamic | Type | Default Value | Valid Values/Value Range | Description |
txsql_nonblock_ddl | yes | bool | false | true/false | Whether to enable the Nonblocking DDL feature. |
txsql_nonblock_ddl_retry_times | yes | ulong | 1 | 0-ulong_max | Retry count after a DDL operation is blocked by an MDL lock. The default value is 1. |
txsql_nonblock_ddl_retry_interval | yes | ulong | 2 | 0-ulong_max | Retry interval after a DDL operation is blocked by an MDL lock. The default value is 2s. |
Note:
Some uncommon DDL operations may not be covered. In these scenarios, if a DDL operation is blocked by a DML statement, the system will directly return
Lock wait timeout.
Yes
No
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