HiveJdbc

DBC Hive Source Connector

Support Hive Version​

• Definitely supports 3.1.3 and 3.1.2, other versions need to be tested.

Key Features​

• batch

• stream

• exactly-once

• column projection

• parallelism

• support user-defined split

supports query SQL and can achieve projection effect.

Description​

Read external data source data through JDBC.

Supported DataSource Info​

Datasource	Supported versions	Driver	Url
Hive	Different dependency version has different driver class.	org.apache.hive.jdbc.HiveDriver	jdbc:hive2://localhost:10000/default

Data Type Mapping​

Hive Data Type	Nexus Data Type
BOOLEAN	BOOLEAN
TINYINT SMALLINT	SHORT
INT INTEGER	INT
BIGINT	LONG
FLOAT	FLOAT
DOUBLE DOUBLE PRECISION	DOUBLE
DECIMAL(x,y) NUMERIC(x,y) (Get the designated column's specified column size.<38)	DECIMAL(x,y)
DECIMAL(x,y) NUMERIC(x,y) (Get the designated column's specified column size.>38)	DECIMAL(38,18)
CHAR VARCHAR STRING	STRING
DATE	DATE
DATETIME TIMESTAMP	TIMESTAMP
BINARY ARRAY INTERVAL MAP STRUCT UNIONTYPE	Not supported yet

Source Options​

Name	Type	Required	Default	Description
url	String	Yes	-	The URL of the JDBC connection. Refer to a case: jdbc:hive2://localhost:10000/default
driver	String	Yes	-	The jdbc class name used to connect to the remote data source, if you use Hive the value is org.apache.hive.jdbc.HiveDriver.
user	String	No	-	Connection instance user name
password	String	No	-	Connection instance password
query	String	Yes	-	Query statement
connection_check_timeout_sec	Int	No	30	The time in seconds to wait for the database operation used to validate the connection to complete
partition_column	String	No	-	The column name for parallelism's partition, only support numeric type,Only support numeric type primary key, and only can config one column.
partition_lower_bound	BigDecimal	No	-	The partition_column min value for scan, if not set Nexus will query database get min value.
partition_upper_bound	BigDecimal	No	-	The partition_column max value for scan, if not set NExus will query database get max value.
partition_num	Int	No	job parallelism	The number of partition count, only support positive integer. default value is job parallelism
fetch_size	Int	No	0	For queries that return a large number of objects,you can configure the row fetch size used in the query toimprove performance by reducing the number database hits required to satisfy the selection criteria. Zero means use jdbc default value.
common-options		No	-	Source plugin common parameters, please refer to Source Common Options for details
useKerberos	Boolean	No	no	Whether to enable Kerberos, default is false
kerberos_principal	String	No	-	When use kerberos, we should set kerberos principal such as 'test_user@xxx'.
kerberos_keytab_path	String	No	-	When use kerberos, we should set kerberos principal file path such as '/home/test/test_user.keytab' .
krb5_path	String	No	/etc/krb5.conf	When use kerberos, we should set krb5 path file path such as '/nexus/krb5.conf' or use the default path '/etc/krb5.conf '.

Tips​

If partition_column is not set, it will run in single concurrency, and if partition_column is set, it will be executed in parallel according to the concurrency of tasks , When your shard read field is a large number type such as bigint( and above and the data is not evenly distributed, it is recommended to set the parallelism level to 1 to ensure that the data skew problem is resolved

Task Example​

Simple:​

This example queries type_bin 'table' 16 data in your test "database" in single parallel and queries all of its fields. You can also specify which fields to query for final output to the console.

# Defining the runtime environment
env {
  parallelism = 2
  job.mode = "BATCH"
}
source{
    Jdbc {
        url = "jdbc:hive2://localhost:10000/default"
        driver = "org.apache.hive.jdbc.HiveDriver"
        connection_check_timeout_sec = 100
        query = "select * from type_bin limit 16"
    }
}

transform {
    # If you would like to get more information about how to configure nexus and see full list of transform plugins,
    # please go to transform page

sink {
    Console {}
}

Parallel:​

Read your query table in parallel with the shard field you configured and the shard data You can do this if you want to read the whole table

source {
    Jdbc {
        url = "jdbc:hive2://localhost:10000/default"
        driver = "org.apache.hive.jdbc.HiveDriver"
        connection_check_timeout_sec = 100
        # Define query logic as required
        query = "select * from type_bin"
        # Parallel sharding reads fields
        partition_column = "id"
        # Number of fragments
        partition_num = 10
    }
}

Parallel Boundary:​

It is more efficient to specify the data within the upper and lower bounds of the query It is more efficient to read your data source according to the upper and lower boundaries you configured

source {
    Jdbc {
        url = "jdbc:hive2://localhost:10000/default"
        driver = "org.apache.hive.jdbc.HiveDriver"
        connection_check_timeout_sec = 100
        # Define query logic as required
        query = "select * from type_bin"
        partition_column = "id"
        # Read start boundary
        partition_lower_bound = 1
        # Read end boundary
        partition_upper_bound = 500
        partition_num = 10
    }
}