This page provides information about the DR Bucket Render Channel in V-Ray for Blender.
Overview
The Distributed Rendering Bucket Render Channel renders an image with each bucket shown in a different color, and a short text on each bucket naming the machine that rendered it. A bucket is a region of an image that is being rendered. The render setup must be set to use the Bucket image sampler, which divides the rendering process into render buckets. This render element is useful for assessing machine performance or for troubleshooting a distributed rendering process.
UI Path: ||V-Ray Node Editor|| > World > Render Channels > Utility > V-Ray DR Bucket

Properties
See the Render Channels page to find out where you can find these properties.
Channel Name – Customizable name for the render channel.
Enable Deep Output – Specifies whether to include this render channel in deep images.
Text Alignment – Sets the alignment of the machine name that is displayed on each bucket.