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LocalFile

Local file sink connector

Description

Output data to local file.

Key features

By default, we use 2PC commit to ensure exactly-once

Options

name type required default value
path string yes -
file_name_expression string no "${transactionId}"
file_format string no "text"
filename_time_format string no "yyyy.MM.dd"
field_delimiter string no '\001'
row_delimiter string no "\n"
partition_by array no -
partition_dir_expression string no "${k0}=${v0}/${k1}=${v1}/.../${kn}=${vn}/"
is_partition_field_write_in_file boolean no false
sink_columns array no When this parameter is empty, all fields are sink columns
is_enable_transaction boolean no true
batch_size int no 1000000
common-options no -

path [string]

The target dir path is required.

file_name_expression [string]

file_name_expression describes the file expression which will be created into the path. We can add the variable ${now} or ${uuid} in the file_name_expression, like test_${uuid}_${now}, ${now} represents the current time, and its format can be defined by specifying the option filename_time_format.

Please note that, If is_enable_transaction is true, we will auto add ${transactionId}_ in the head of the file.

file_format [string]

We supported as the following file types:

text csv parquet orc json

Please note that, The final file name will ends with the file_format's suffix, the suffix of the text file is txt.

filename_time_format [string]

When the format in the file_name_expression parameter is xxxx-${now} , filename_time_format can specify the time format of the path, and the default value is yyyy.MM.dd . The commonly used time formats are listed as follows:

Symbol Description
y Year
M Month
d Day of month
H Hour in day (0-23)
m Minute in hour
s Second in minute

See Java SimpleDateFormat for detailed time format syntax.

field_delimiter [string]

The separator between columns in a row of data. Only needed by text and csv file format.

row_delimiter [string]

The separator between rows in a file. Only needed by text and csv file format.

partition_by [array]

Partition data based on selected fields

partition_dir_expression [string]

If the partition_by is specified, we will generate the corresponding partition directory based on the partition information, and the final file will be placed in the partition directory.

Default partition_dir_expression is ${k0}=${v0}/${k1}=${v1}/.../${kn}=${vn}/. k0 is the first partition field and v0 is the value of the first partition field.

is_partition_field_write_in_file [boolean]

If is_partition_field_write_in_file is true, the partition field and the value of it will be write into data file.

For example, if you want to write a Hive Data File, Its value should be false.

sink_columns [array]

Which columns need be write to file, default value is all of the columns get from Transform or Source. The order of the fields determines the order in which the file is actually written.

is_enable_transaction [boolean]

If is_enable_transaction is true, we will ensure that data will not be lost or duplicated when it is written to the target directory.

Please note that, If is_enable_transaction is true, we will auto add ${transactionId}_ in the head of the file.

Only support true now.

batch_size [int]

The maximum number of rows in a file. For SeaTunnel Engine, the number of lines in the file is determined by batch_size and checkpoint.interval jointly decide. If the value of checkpoint.interval is large enough, sink writer will write rows in a file until the rows in the file larger than batch_size. If checkpoint.interval is small, the sink writer will create a new file when a new checkpoint trigger.

common options

Sink plugin common parameters, please refer to Sink Common Options for details.

Example

For text file format

LocalFile {
    path = "/tmp/hive/warehouse/test2"
    field_delimiter = "\t"
    row_delimiter = "\n"
    partition_by = ["age"]
    partition_dir_expression = "${k0}=${v0}"
    is_partition_field_write_in_file = true
    file_name_expression = "${transactionId}_${now}"
    file_format = "text"
    sink_columns = ["name","age"]
    filename_time_format = "yyyy.MM.dd"
    is_enable_transaction = true
}

For parquet file format

LocalFile {
    path = "/tmp/hive/warehouse/test2"
    partition_by = ["age"]
    partition_dir_expression = "${k0}=${v0}"
    is_partition_field_write_in_file = true
    file_name_expression = "${transactionId}_${now}"
    file_format = "parquet"
    sink_columns = ["name","age"]
    filename_time_format = "yyyy.MM.dd"
    is_enable_transaction = true
}

For orc file format

LocalFile {
    path = "/tmp/hive/warehouse/test2"
    partition_by = ["age"]
    partition_dir_expression = "${k0}=${v0}"
    is_partition_field_write_in_file = true
    file_name_expression = "${transactionId}_${now}"
    file_format = "orc"
    sink_columns = ["name","age"]
    filename_time_format = "yyyy.MM.dd"
    is_enable_transaction = true
}

Changelog

2.2.0-beta 2022-09-26

  • Add Local File Sink Connector

2.3.0-beta 2022-10-20

  • [BugFix] Fix the bug of incorrect path in windows environment (2980)
  • [BugFix] Fix filesystem get error (3117)
  • [BugFix] Solved the bug of can not parse '\t' as delimiter from config file (3083)

Next version

  • [BugFix] Fixed the following bugs that failed to write data to files (3258)

    • When field from upstream is null it will throw NullPointerException
    • Sink columns mapping failed
    • When restore writer from states getting transaction directly failed

  • [Improve] Support setting batch size for every file (3625)