Sign InTry Free

Data Check in the Sharding Scenario

sync-diff-inspector supports data check in the sharding scenario. Assume that you use the TiDB Data Migration tool to replicate data from multiple MySQL instances into TiDB, you can use sync-diff-inspector to check upstream and downstream data.

For scenarios where the number of upstream sharded tables is small and the naming rules of sharded tables do not have a pattern as shown below, you can use Datasource config to configure table-0, set corresponding rules and configure the tables that have the mapping relationship between the upstream and downstream databases. This configuration method requires setting all sharded tables.

shard-table-replica-1

Below is a complete example of the sync-diff-inspector configuration.

# Diff Configuration. ######################### Global config ######################### # The number of goroutines created to check data. The number of connections between upstream and downstream databases are slightly greater than this value check-thread-count = 4 # If enabled, SQL statements is exported to fix inconsistent tables export-fix-sql = true # Only compares the table structure instead of the data check-struct-only = false ######################### Datasource config ######################### [data-sources.mysql1] host = "127.0.0.1" port = 3306 user = "root" password = "" route-rules = ["rule1"] [data-sources.mysql2] host = "127.0.0.1" port = 3306 user = "root" password = "" route-rules = ["rule2"] [data-sources.tidb0] host = "127.0.0.1" port = 4000 user = "root" password = "" ########################### Routes ########################### [routes.rule1] schema-pattern = "test" # Matches the schema name of the data source. Supports the wildcards "*" and "?" table-pattern = "table-[1-2]" # Matches the table name of the data source. Supports the wildcards "*" and "?" target-schema = "test" # The name of the schema in the target database target-table = "table-0" # The name of the target table [routes.rule2] schema-pattern = "test" # Matches the schema name of the data source. Supports the wildcards "*" and "?" table-pattern = "table-3" # Matches the table name of the data source. Supports the wildcards "*" and "?" target-schema = "test" # The name of the schema in the target database target-table = "table-0" # The name of the target table ######################### Task config ######################### [task] output-dir = "./output" source-instances = ["mysql1", "mysql2"] target-instance = "tidb0" # The tables of downstream databases to be compared. Each table needs to contain the schema name and the table name, separated by '.' target-check-tables = ["test.table-0"]

You can use table-rules for configuration when there are a large number of upstream sharded tables and the naming rules of all sharded tables have a pattern, as shown below:

shard-table-replica-2

Below is a complete example of the sync-diff-inspector configuration.

# Diff Configuration. ######################### Global config ######################### # The number of goroutines created to check data. The number of connections between upstream and downstream databases are slightly greater than this value. check-thread-count = 4 # If enabled, SQL statements is exported to fix inconsistent tables. export-fix-sql = true # Only compares the table structure instead of the data. check-struct-only = false ######################### Datasource config ######################### [data-sources.mysql1] host = "127.0.0.1" port = 3306 user = "root" password = "" [data-sources.mysql2] host = "127.0.0.1" port = 3306 user = "root" password = "" [data-sources.tidb0] host = "127.0.0.1" port = 4000 user = "root" password = "" ########################### Routes ########################### [routes.rule1] schema-pattern = "test" # Matches the schema name of the data source. Supports the wildcards "*" and "?" table-pattern = "table-*" # Matches the table name of the data source. Supports the wildcards "*" and "?" target-schema = "test" # The name of the schema in the target database target-table = "table-0" # The name of the target table ######################### Task config ######################### [task] output-dir = "./output" source-instances = ["mysql1", "mysql2"] target-instance = "tidb0" # The tables of downstream databases to be compared. Each table needs to contain the schema name and the table name, separated by '.' target-check-tables = ["test.table-0"]

Note

If test.table-0 exists in the upstream database, the downstream database also compares this table.

Was this page helpful?

Download PDFRequest docs changesAsk questions on DiscordEdit this page
Playground
New
One-stop & interactive experience of TiDB's capabilities WITHOUT registration.
Products
TiDB
TiDB Dedicated
TiDB Serverless
Pricing
Get Demo
Get Started
© 2023 PingCAP. All Rights Reserved.
Privacy Policy.