The ThingWorx File Transfer Subsystem supports compression for file uploads performed using the Copy service. ThingWorx SCM and the eMessage Connector support Upload instructions for compressed files only.

In Axeda Platform, the configuration setting known as the "compression high threshold" (com.axeda.drm.scm.upload.compression-high-threshold) is sent down to the agent as part of the upload instruction. The compressionHighThreshold configuration setting for the eMessage Connector has a default value of 2,147,483,648 (2 GB). The eMessage Connector sends the value of this setting to the agent. The agent compresses the files to be uploaded so that it uploads only a single compressed file. As long as the total size of the files is less than the value of compressionHighThreshold, the agent compresses them and sends them as a single, tar.gz formatted file. Once uploaded to the SCM repository on the ThingWorx Platform, the tar.gz file can be extracted and used.

If multiple files are to be uploaded and their total size exceeds the compressionHighThreshold value, the agent does not compress them, even if the instruction tells the agent to compress them. For instructions that have a file specification that uses wild cards and for those with multiple file specifications, the instruction fails since multiple files cannot be transferred uncompressed.

If a single file to be uploaded exceeds the compressionHighThreshold, the agent sends the file uncompressed. This file is uploaded to the SCM repository on the ThingWorx platform, under <ThingName>/<deliveryTargetID>_<instructionOrdinal>/<uncompressed-file-name-as-in-agent>.