The Transform Service performs transformations for Alfresco Content Service in docker containers providing greater scalability. Requests to the Transform Service are placed on a queue and processed asynchronously. Security is also improved by better isolation.
It is possible to turn on and off Local, Legacy and Transform Service transforms by setting Alfresco global properties. By default the Transform Service is disabled for the zip distribution but enabled for docker-compose and helm deployments.
Requests made to the V1 REST API for renditions make use of the RenditionService2 which supports asynchronous requests. A request may be made on one Alfresco node and the resulting transform from the Transform Service may be processed on a different node.
The RenditionService2 will use the Transform Service if it is available and is known to support the transformation specified in the RenditionDefinition2. If not, the service with fallback to the transformers performed locally by Alfresco Content Service.
For more information see Custom Transforms and Renditions.
The original RenditionService is now deprecated as it supports synchronous requests or requests that have callbacks that must be processed on the same node. It still exists and a number of existing calls that can be asynchronous without a callback been modified to use the RenditionService2 if there is an equivalent RenditionDefinition2.