- Release Notes and Announcements
- Product Introduction
- Purchase Guide
- Getting Started
- Access Management
- Preparations
- Data Migration
- Databases Supported by Data Migration
- Cross-Account TencentDB Instance Migration
- Migrating to MySQL
- Migrating to MariaDB
- Migrating to TDSQL-C for MySQL
- Migrating to TDSQL MySQL
- Migrating to PostgreSQL
- Migrating to MongoDB
- Migrating to SQL Server
- Migrating to TencentDB for Redis
- Offline Migration of MySQL Data
- Advanced Migration Operations
- Task Management
- Data Sync
- Databases Supported by Data Sync
- Cross-Account TencentDB Instance Sync
- Synchronize to PostgreSQL
- Sync into Tencent Cloud
- Sync from Tencent Cloud
- Advanced Sync Operations
- Task Management
- Task Status Description
- Viewing Task
- Starting Task
- Retrying Task (MySQL)
- Verifying Task
- Stopping Task
- Pausing Task
- Resuming Task
- Resetting Task
- Deleting Task
- Changing Configuration
- Transition from Pay-as-You-Go to Monthly Subscription
- Terminating/Returning Instance
- Renewing Task
- Deisolating Task
- Deleting Instance
- Viewing Log
- Deleting Task
- Data Subscription (Kafka Edition)
- Databases Supported by Data Subscription
- Creating Data Subscription Task
- Data Consumption
- Creating Consumer Group
- Managing Consumer Group
- Consuming MySQL Data
- Consuming MongoDB Data
- Consuming TDSQL for PostgreSQL Data
- Consuming Subscribed Data with Kafka Client (Protobuf)
- Consuming Subscribed Data with Kafka Client (Avro)
- Consuming Subscribed Data with Kafka Client (JSON)
- Consuming Subscribed Data with Flink Client (Avro)
- Consuming Data with Flink
- Advanced Subscription Operations
- Task Management
- Data Migration (OldDTS)
- Data Subscription (OldDTS)
- Fix for Verification Failure
- Check Item Overview
- Check Items of MySQL/MariaDB/Percona/TDSQL-C for MySQL/TDSQL for MySQL
- MongoDB Check Items
- PostgreSQL Check Items
- TDSQL for PostgreSQL
- Redis/Tendis
- SQL Server
- Database Connection Check
- Source Database Existence Check
- Target Database Existence Check
- Peripheral Check
- Migration Network Check
- Version Check
- Source Instance Permission Check
- Account Conflict Check
- Partial Database Parameter Check
- Source Instance Parameter Check
- Source Instance Type (Master or Replica)
- Parameter Configuration Conflict Check
- Target Database Content Conflict Check
- Target Database Space Check
- Target Database Load Check
- Local Disk Space Check
- Binlog Parameter Check
- Oplog Check
- Foreign Key Dependency Check
- View Check
- Advanced Object Check
- Incremental Migration Precondition Check
- Extension/Plugin Compatibility Check
- Source Database Balancer Check
- Source Database Node Role Check
- ShardKey Check
- Warning Item Check
- DLL Ring Sync Check for Single Database/Table Object
- DLL Sync Conflict Check for Single Database/Table Object in the Same Target
- Level-2 Subpartitioned Table Check
- Primary Key Check
- DDL Check for Tables to Be Migrated
- System Database Conflict Check
- Table Structure Check for Source and Target Instances
- InnoDB Table Check
- Migration Object Dependency Check
- Constraint Check
- Cutover Description
- Monitoring and Alarms
- Ops Management
- DTS-DBbridge
- Best Practices
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- (NewDTS) Data Migration APIs
- DescribeMigrationJobs
- DescribeMigrationDetail
- CreateMigrationService
- ModifyMigrationJob
- CreateMigrateCheckJob
- DescribeMigrationCheckJob
- SkipCheckItem
- StartMigrateJob
- StopMigrateJob
- ResumeMigrateJob
- RecoverMigrateJob
- ModifyMigrateName
- ModifyMigrateJobSpec
- IsolateMigrateJob
- DestroyMigrateJob
- DescribeMigrateDBInstances
- CompleteMigrateJob
- PauseMigrateJob
- ContinueMigrateJob
- Data Sync APIs
- ModifySyncJobConfig
- CreateModifyCheckSyncJob
- DescribeModifyCheckSyncJobResult
- StartModifySyncJob
- DescribeSyncJobs
- CreateSyncJob
- ConfigureSyncJob
- CreateCheckSyncJob
- SkipSyncCheckItem
- DescribeCheckSyncJobResult
- StartSyncJob
- StopSyncJob
- ResumeSyncJob
- ResizeSyncJob
- RecoverSyncJob
- IsolateSyncJob
- DestroySyncJob
- PauseSyncJob
- ContinueSyncJob
- Data Consistency Check APIs
- Data Types
- Error Codes
- DTS API 2018-03-30
- SDK Documentation
- FAQs
- Error Handling (NewDTS)
- Error Handling (OldDTS)
- Service Agreement
- Release Notes and Announcements
- Product Introduction
- Purchase Guide
- Getting Started
- Access Management
- Preparations
- Data Migration
- Databases Supported by Data Migration
- Cross-Account TencentDB Instance Migration
- Migrating to MySQL
- Migrating to MariaDB
- Migrating to TDSQL-C for MySQL
- Migrating to TDSQL MySQL
- Migrating to PostgreSQL
- Migrating to MongoDB
- Migrating to SQL Server
- Migrating to TencentDB for Redis
- Offline Migration of MySQL Data
- Advanced Migration Operations
- Task Management
- Data Sync
- Databases Supported by Data Sync
- Cross-Account TencentDB Instance Sync
- Synchronize to PostgreSQL
- Sync into Tencent Cloud
- Sync from Tencent Cloud
- Advanced Sync Operations
- Task Management
- Task Status Description
- Viewing Task
- Starting Task
- Retrying Task (MySQL)
- Verifying Task
- Stopping Task
- Pausing Task
- Resuming Task
- Resetting Task
- Deleting Task
- Changing Configuration
- Transition from Pay-as-You-Go to Monthly Subscription
- Terminating/Returning Instance
- Renewing Task
- Deisolating Task
- Deleting Instance
- Viewing Log
- Deleting Task
- Data Subscription (Kafka Edition)
- Databases Supported by Data Subscription
- Creating Data Subscription Task
- Data Consumption
- Creating Consumer Group
- Managing Consumer Group
- Consuming MySQL Data
- Consuming MongoDB Data
- Consuming TDSQL for PostgreSQL Data
- Consuming Subscribed Data with Kafka Client (Protobuf)
- Consuming Subscribed Data with Kafka Client (Avro)
- Consuming Subscribed Data with Kafka Client (JSON)
- Consuming Subscribed Data with Flink Client (Avro)
- Consuming Data with Flink
- Advanced Subscription Operations
- Task Management
- Data Migration (OldDTS)
- Data Subscription (OldDTS)
- Fix for Verification Failure
- Check Item Overview
- Check Items of MySQL/MariaDB/Percona/TDSQL-C for MySQL/TDSQL for MySQL
- MongoDB Check Items
- PostgreSQL Check Items
- TDSQL for PostgreSQL
- Redis/Tendis
- SQL Server
- Database Connection Check
- Source Database Existence Check
- Target Database Existence Check
- Peripheral Check
- Migration Network Check
- Version Check
- Source Instance Permission Check
- Account Conflict Check
- Partial Database Parameter Check
- Source Instance Parameter Check
- Source Instance Type (Master or Replica)
- Parameter Configuration Conflict Check
- Target Database Content Conflict Check
- Target Database Space Check
- Target Database Load Check
- Local Disk Space Check
- Binlog Parameter Check
- Oplog Check
- Foreign Key Dependency Check
- View Check
- Advanced Object Check
- Incremental Migration Precondition Check
- Extension/Plugin Compatibility Check
- Source Database Balancer Check
- Source Database Node Role Check
- ShardKey Check
- Warning Item Check
- DLL Ring Sync Check for Single Database/Table Object
- DLL Sync Conflict Check for Single Database/Table Object in the Same Target
- Level-2 Subpartitioned Table Check
- Primary Key Check
- DDL Check for Tables to Be Migrated
- System Database Conflict Check
- Table Structure Check for Source and Target Instances
- InnoDB Table Check
- Migration Object Dependency Check
- Constraint Check
- Cutover Description
- Monitoring and Alarms
- Ops Management
- DTS-DBbridge
- Best Practices
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- (NewDTS) Data Migration APIs
- DescribeMigrationJobs
- DescribeMigrationDetail
- CreateMigrationService
- ModifyMigrationJob
- CreateMigrateCheckJob
- DescribeMigrationCheckJob
- SkipCheckItem
- StartMigrateJob
- StopMigrateJob
- ResumeMigrateJob
- RecoverMigrateJob
- ModifyMigrateName
- ModifyMigrateJobSpec
- IsolateMigrateJob
- DestroyMigrateJob
- DescribeMigrateDBInstances
- CompleteMigrateJob
- PauseMigrateJob
- ContinueMigrateJob
- Data Sync APIs
- ModifySyncJobConfig
- CreateModifyCheckSyncJob
- DescribeModifyCheckSyncJobResult
- StartModifySyncJob
- DescribeSyncJobs
- CreateSyncJob
- ConfigureSyncJob
- CreateCheckSyncJob
- SkipSyncCheckItem
- DescribeCheckSyncJobResult
- StartSyncJob
- StopSyncJob
- ResumeSyncJob
- ResizeSyncJob
- RecoverSyncJob
- IsolateSyncJob
- DestroySyncJob
- PauseSyncJob
- ContinueSyncJob
- Data Consistency Check APIs
- Data Types
- Error Codes
- DTS API 2018-03-30
- SDK Documentation
- FAQs
- Error Handling (NewDTS)
- Error Handling (OldDTS)
- Service Agreement
Check Details
row_format in the source database table cannot be FIXED.The values of the
lower_case_table_names variable in both the source and target databases must be the same.The
max_allowed_packet parameter of the target database must be set to 4 MB or above.The
connect_timeout variable of the source database must be above 10.In migration from MySQL/TDSQL for MySQL/TDSQL-C to MySQL, if a time-consuming SQL statement is running on the source database, a warning will be reported, with the content being "A time-consuming SQL statement is running on the source database, which may cause table locks. Please try again later or process the SQL statement on the source database".
Troubleshooting
Modifying the row_format parameter in the source database
If the value of
row_format in a database table is FIXED, an error will be reported when the storage length of each row of the table exceeds the limit. Therefore, you need to change the value of row_format to DYNAMIC so that the storage length of each row varies by the content length.If a similar error occurs, fix it as follows:
1. Log in to the source database.
2. Set
row_format to DYNAMIC.alter table table_name row_format = DYNAMIC;
3. Check whether the configuration takes effect.
show table status like 'table_name'\\G;
The system will display a result similar to the following:
mysql> show table status like 'table_name'\\G;*************************** 1. row ***************************Name: table_nameEngine: InnoDBVersion: 10Row_format: DynamicRows: 5......1 row in set (0.00 sec)
4. Run the verification task again.
Making lower_case_table_names have the same value in source and target databases
lower_case_table_names sets the letter case sensitivity in MySQL. It has the following valid values:
Windows and macOS environments are case-insensitive, but Linux environments are case-sensitive. To ensure the compatibility between different operating systems, you need to use the same letter case sensitivity rule.0: The name of a stored table is in the specified letter case and is case-sensitive during comparison.1: The name of a stored table is in lowercase on the disk and is case-insensitive during comparison.2: The name of a stored table is in the specified letter case and is in lowercase during comparison.If a similar error occurs, set the parameter in the source and target databases to the same value as follows:
1. Log in to the source database.
2. Check the values of
lower_case_table_names in the source and target databases.show variables like '%lower_case_table_names%';
3. Modify the
my.cnf configuration file of the source database as follows:Note
The default path of the
my.cnf configuration file is /etc/my.cnf, subject to the actual conditions.lower_case_table_names = 1
4. Run the following command to restart the database:
[$Mysql_Dir]/bin/mysqladmin -u root -p shutdown[$Mysql_Dir]/bin/safe_mysqld &
5. Check whether the configuration takes effect.
show variables like '%lower_case_table_names%';
The system will display a result similar to the following:
mysql> show variables like '%lower_case_table_names%';+------------------------+-------+| Variable_name | Value |+------------------------+-------+| lower_case_table_names | 1 |+------------------------+-------+1 row in set (0.00 sec)
6. Run the verification task again.
Modifying the max_allowed_packet parameter in the target database
max_allowed_packet is the maximum size of a packet that can be transferred. If its value is too large, more memory will be used, causing packet losses and the inability to capture the SQL statements of large exception event packets. If its value is too small, program errors may occur, causing backup failures and frequent sending/receiving of network packets, which compromises the system performance.If a similar error occurs, fix it as follows:
1. Log in to the target database.
2. Modify the
max_allowed_packet parameter.set global max_allowed_packet = 4*1024*1024;
3. Check whether the configuration takes effect.
show global variables like '%max_allowed_packet%';
The system will display a result similar to the following:
mysql> show global variables like '%max_allowed_packet%';+------------------------+---------+| Variable_name | Value |+------------------------+---------+| max_allowed_packet | 4194304 |+------------------------+---------+1 row in set (0.00 sec)
4. Run the verification task again.
Modifying the connect_timeout variable in the source database
connect_timeout is the database connection timeout, and a connection request will be denied if the connection duration is greater than the value of connect_timeout. If the value of connect_timeout is too small, the database will be frequently disconnected, which will impact the database processing efficiency. Therefore, we recommend that you set a value greater than 10 for this parameter.If a similar error occurs, fix it as follows:
1. Log in to the source database.
2. Modify the
connect_timeout parameter.set global connect_timeout = 10;
3. Check whether the configuration takes effect.
show global variables like '%connect_timeout%';
The system will display a result similar to the following:
mysql> show global variables like '%connect_timeout%';+------------------------+---------+| Variable_name | Value |+------------------------+---------+| connect_timeout | 10 |+------------------------+---------+1 row in set (0.00 sec)
4. Run the verification task again.
Yes
No
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