DataWeave System Properties

DataWeave supports several system properties. To use these properties in application development and deployments, see System Properties.

Property Description

com.mulesoft.dw.buffer.memory.monitoring

Experimental: When set to true, logs a message each time a slot from the memory pool is taken or released. The behavior is useful for troubleshooting. com.mulesoft.dw.buffer.memory.monitoring supports an experimental feature that is subject to change or removal from future versions of DataWeave.

  • Type: Boolean

  • Default: false

com.mulesoft.dw.buffersize

Sets the size (in bytes) of in-memory input and output buffers that DataWeave uses to retain processed inputs and outputs. DataWeave stores payloads that exceed this size in temporary files dw-buffer-index-${count}.tmp and dw-buffer-output-${count}.tmp. See DataWeave Memory Management.

  • Type: Number (in bytes)

  • Default: 8192 bytes (8 KB)

com.mulesoft.dw.coercionexception.verbose

By default, adds to coercion exceptions more information about data that fails to coerce. When this property is set to false, DataWeave does not display the additional metadata.

  • Type: Boolean

  • Default: true

com.mulesoft.dw.date_minus_back_compatibility

Restores the Add and Subtract Time behaviors that changed in 2.3.0 when this property is set to true.

  • Type: Boolean

  • Default: false

For example, consider the following DataWeave script:

%dw 2.0
output application/dw
---
|2019-10-01| - |2018-09-23|
  • In DataWeave 2.3.0, the expression returns PT8952H.

  • In DataWeave 2.2.0, the expression returns P1Y8D.

com.mulesoft.dw.directbuffer.disable

Controls whether DataWeave uses off-heap memory (the default) or heap memory. DataWeave uses off-heap memory for internal buffering, which can cause issues on systems that have only a small amount of memory. See DataWeave Memory Management.

  • Type: Boolean

  • Default: false

com.mulesoft.dw.dump_files

Experimental: Dumps the input context and the failing script into a folder when this property is set to true. This behavior enables you to track the failing script and the data that makes the script fail, which is particularly useful for verifying that the received input data is valid. Incorrect scripts often fail when an upstream component generates invalid data.

  • Type: Boolean

  • Default: false

com.mulesoft.dw.dump_files is an experimental feature that is subject to change or removal from future versions of DataWeave. See Troubleshooting a Failing DataWeave Script.

com.mulesoft.dw.dump_folder

Experimental: Specifies the path in which to dump files when com.mulesoft.dw.dump_files is set to true.

  • Type: String

  • Default: java.io.tmpdir (system property value)

com.mulesoft.dw.dump_folder is an experimental feature that is subject to change or removal from future versions of DataWeave. See Troubleshooting a Failing DataWeave Script.

com.mulesoft.dw.error_value_length

Sets the maximum length of exception messages to display to the user. The message is truncated to the maximum length. This setting is useful for avoiding long exception messages.

  • Type: Number

  • Default: 80

com.mulesoft.dw.indexsize

Sets the maximum size (in bytes) of the page in memory that indexed readers use.

  • Type: Number

  • Default: 1572864 (1.5 MB)

com.mulesoft.dw.max_memory_allocation

Sets the size (in bytes) of each slot in the off-heap memory pool.

  • Type: Number (in bytes)

  • Default: 1572864 (1.5 MB)

com.mulesoft.dw.memory_pool_size

Sets the number of slots in the memory pool. DataWeave buffers use off-heap memory from a pool, up to a defined size (com.mulesoft.dw.memory_pool_size * com.mulesoft.dw.max_memory_allocation). DataWeave allocates the remainder using heap memory. See DataWeave Memory Management.

  • Type: Number

  • Default: 60

com.mulesoft.dw.multipart.defaultContentType

Sets the default Content-Type to use on parts of the multipart/* format when a Content-Type is not specified. See also, the multipart reader property defaultContentType. Introduced in DataWeave 2.3 (2.3.0-20210720) for the August 2021 release of Mule 4.3.0-20210719.

  • Type: String

  • Default: application/octet-stream

com.mulesoft.dw.valueSelector.selectsAlwaysFirst

When set to set to true, returns the first occurrence of an element (even if the element appears more than once). Enabling this behavior degrades performance.

  • Type: Boolean

  • Default: false

The following example illustrates the behavior that is controlled by this property. (Assume that the DataWeave script acts on the XML input.)

XML input:
<root>
  <users>
     <user>
       <lname>chibana</lname>
       <name>Shoki</name>
     </user>
     <user>
       <name>Shoki</name>
       <name>Tomo</name>
     </user>
  </users>
</root>
DataWeave script:
%dw 2.0
output application/json
---
{
    shokis: payload.root.users.*user map $.name
}
  • If com.mulesoft.dw.valueSelector.selectsAlwaysFirst is set to true, the script returns the following output:

    {
      "shokis": [
        "Shoki",
        "Shoki"
      ]
    }
  • If com.mulesoft.dw.valueSelector.selectsAlwaysFirst is set to false, the script returns the following output:

    {
      "shokis": [
        "Shoki",
        "Tomo"
      ]
    }

com.mulesoft.dw.stacksize

Sets the maximum size of the stack. When a function recurses too deeply, DataWeave throws an error, such as Stack Overflow. Max stack is 256.

  • Type: Number

  • Default: 256

com.mulesoft.dw.xml.supportDTD

Controls whether DTD handling is enabled or disabled. When this property is set to false, DataWeaves skips processing of both internal and external subsets. Note that the default for this property changed from true to false in Mule version 4.3.0-20210427, which includes the May, 2021 patch of DataWeave version 2.3.0.

  • Type: Boolean

  • Default: false

com.mulesoft.dw.track.cursor.close

When set to true, tracks the stack trace from which the CursorProvider#close() method is called. Use this property for troubleshooting, for example, if CursorProvider#openCursor() is called on a cursor that is already closed.

  • Type: Boolean

  • Default: false

com.mulesoft.dw.verbose

Displays filtered stack traces when this property is set to true. Does not display stack traces when set to false.

  • Type: Boolean

  • Default: false

Was this article helpful?

💙 Thanks for your feedback!

Edit on GitHub