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DataWeave Memory Management

When processing large files through DataWeave in Mule, there are a few things you can set up to fine-tune how much memory will be used up and when.

Memory vs Disk Usage

DataWeave uses the system’s memory as a buffer while processing a transformation unless a certain threshold is exceeded, in which case it resorts to using the system’s hard disk as a buffer. By default, this threshold is set at 1572864 bytes, but this value may be changed. The value refers to memory usage of each individual Transform component, not to an aggregate of all the ones in the project.

To change the threshold value at which memory is no longer used as a buffer, you must add a system property com.mulesoft.dw.buffersize and assign it the number (in bytes) of your new threshold. System properties may be defined in several ways. See system properties for more details and more ways you can set these.

The value you assign to this property affects your entire Mule application, affecting each instance of the Transform component individually.

Please note that for Mule runtime versions 3.8.3 and older, all indexed readers can process payloads with a maximum limit of 2 GB. Also, the text length for a single field can not be larger than 1 MB (this applies for CSV, JSON and XML).