This topic describes the data types and parameters that HybridDB for MySQL Writer supports and how to configure it by using the codeless user interface (UI) and code editor.

HybridDB for MySQL Writer allows you to write data to tables stored in HybridDB for MySQL databases. Specifically, HybridDB for MySQL Writer connects to a remote HybridDB for MySQL database by using Java Database Connectivity (JDBC), and executes an INSERT INTO or a REPLACE INTO statement to write data to the HybridDB for MySQL database. HybridDB for MySQL uses the InnoDB engine so that data is written to the database in batches.
Note You must configure a HybridDB for MySQL connection before you configure HybridDB for MySQL Writer. For more information, see Configure a HybridDB for MySQL connection.
HybridDB for MySQL Writer is designed for data developers to import data from data warehouses to HybridDB for MySQL databases. Users such as database administrators can use HybridDB for MySQL Writer as a data migration tool. HybridDB for MySQL Writer obtains data from a Data Integration reader.
Note A sync node that uses HybridDB for MySQL Writer must have at least the permission to execute the INSERT INTO statement. Whether other permissions are required depends on the SQL statements that you specify in the preSql and postSql parameters when you configure the node.

Data types

HybridDB for MySQL Writer supports most HybridDB for MySQL data types. Make sure that your data types are supported.

The following table describes the data types that HybridDB for MySQL Writer supports.
Category HybridDB for MySQL data type
Integer INT, TINYINT, SMALLINT, MEDIUMINT, BIGINT, and YEAR
Floating point FLOAT, DOUBLE, and DECIMAL
String VARCHAR, CHAR, TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT
Date and time DATE, DATETIME, TIMESTAMP, and TIME
Boolean BOOL
Binary TINYBLOB, MEDIUMBLOB, BLOB, LONGBLOB, and VARBINARY

Parameters

Parameter Description Required Default value
datasource The connection name. It must be the same as the name of the added connection. You can add connections in the code editor. Yes N/A
table The name of the destination table. Yes N/A
writeMode The write mode. Valid values:
  • replace into: If no primary key conflict or unique index conflict occurs, the action is the same as that of insert into.
  • insert into: If a primary key conflict or unique index conflict occurs, data cannot be written to the conflicting rows and is regarded as dirty data.
No insert
column The columns in the destination table to which data is written. Separate the columns with commas (,), for example, "column":["id","name","age"]. To write data to all the columns in the destination table, set the value to an asterisk (*), for example, "column":["*"]. Yes N/A
preSql The SQL statement to execute before the sync node is run. For example, you can clear outdated data before data synchronization. You can execute only one SQL statement on the codeless UI and multiple SQL statements in the code editor. No N/A
postSql The SQL statement to execute after the sync node is run. For example, you can add a timestamp after data synchronization. You can execute only one SQL statement on the codeless UI and multiple SQL statements in the code editor. No N/A
batchSize The number of data records to write at a time. Set this parameter to a proper value based on your actual needs. This can greatly reduce the interactions between Data Integration and the HybridDB for MySQL database on the network, and increase the throughput. However, an excessively large value may lead to the out of memory (OOM) error during the data synchronization process. No 1,024

Configure HybridDB for MySQL Writer by using the codeless UI

  1. Configure the connections.
    Configure the connections to the source and destination data stores for the sync node.Select data source section
    Parameter Description
    Data source The datasource parameter in the preceding parameter description. Select a connection type and select the name of a connection that you have configured in DataWorks.
    Table The table parameter in the preceding parameter description.
    Prepare statement before import The preSql parameter in the preceding parameter description. Enter an SQL statement to execute before the sync node is run.
    Complete statement after import The postSql parameter in the preceding parameter description. Enter an SQL statement to execute after the sync node is run.
    Primary key conflict The writeMode parameter in the preceding parameter description. Select the required write mode.
  2. Configure field mapping. It is equivalent to setting the column parameter in the preceding parameter description. Fields in the source table on the left have a one-to-one mapping with fields in the destination table on the right.
    GUI element Description
    The same name mapping Click The same name mapping to establish a mapping between fields with the same name. Note that the data types of the fields must match.
    Peer mapping Click Peer mapping to establish a mapping between fields in the same row. Note that the data types of the fields must match.
    Unmap Click Unmap to remove mappings that have been established.
    Automatic typesetting Click Automatic typesetting to sort the fields based on specified rules.
  3. Configure channel control policies.
    Parameter Description
    Maximum number of concurrent tasks expected The maximum number of concurrent threads that the sync node uses to read data from or write data to data stores. You can configure the concurrency for the node on the codeless UI.
    Synchronization rate Specifies whether to enable bandwidth throttling. You can enable bandwidth throttling and set a maximum transmission rate to avoid heavy read workload of the source. We recommend that you enable bandwidth throttling and set the maximum transmission rate to a proper value.
    The number of error records exceeds The maximum number of dirty data records allowed.

Configure HybridDB for MySQL Writer by using the code editor

You can configure HybridDB for MySQL Writer by using the code editor. For more information, see Create a sync node by using the code editor.

The following example shows how to configure a sync node to write data to a HybridDB for MySQL database. For more information about the parameters, see the preceding parameter description.
{
    "type": "job",
    "steps": [
        {
            "parameter": {},
        {
            "parameter": {
                "postSql": [],// The SQL statement to execute after the sync node is run.
                "datasource": "px_aliyun_hy***",// The connection name.
                "column": [// The columns to which data is written.
                    "id",
                    "name",
                    "sex",
                    "salary",
                    "age",
                    "pt"
                ],
                "writeMode": "insert",// The write mode.
                "batchSize": 256,// The number of data records to write at a time.
                "encoding": "UTF-8",// The encoding format.
                "table": "person_copy",// The name of the destination table.
                "preSql": []// The SQL statement to execute before the sync node is run.
            },
            "name": "Writer",
            "category": "writer"
        }
    ],
    "version": "2.0",// The version number.
    "order": {
        "hops": [
            {
                "from": "Reader",
                "to": "Writer"
            }
        ]
    },
    "setting": {
        "errorLimit": {// The maximum number of dirty data records allowed.
            "record": ""
        },
        "speed": {
            "concurrent": 7,// The number of concurrent threads.
            "throttle": true,// Specifies whether to enable bandwidth throttling. A value of false indicates that the bandwidth is not throttled. A value of true indicates that the bandwidth is throttled. The maximum transmission rate takes effect only if you set this parameter to true.
            "mbps": 1// The maximum transmission rate.
        }
    }
}