1. Apache Flume - Official Vendor Documentation:
Source: Apache Flume 1.11.0 User Guide.
Reference: In the section titled "Multiplexing the Flow", the documentation states: "Flume supports multiplexing the flow from a source to one or more channels. This is achieved using a channel selector that can be configured for a source. The selector can inspect the Event headers to send the event to a specific channel or a set of channels... The multiplexing channel selector is used to do this. It works by matching a header value against a configured mapping of values."
Location: This can be found under the "Flume User Guide" -> "Configuration" -> "Multiplexing the Flow" section of the official Apache Flume project documentation.
2. Huawei FusionInsight - Official Vendor Documentation:
Source: Huawei FusionInsight HD Flume Component Guide.
Reference: The guide details the configuration of a Flume agent, including the source's channel selector. It provides examples for setting the selector.type to multiplexing and then defining selector.mapping. properties. For instance, agent.sources.r1.selector.mapping.state = c1 would route events with a header key 'state' and value 'CA' to channel c1. This directly confirms that data streams can be sent to different channels based on header information.
Location: Typically found in the "Component Guide" or "Administrator Guide" for the Flume service within the FusionInsight HD documentation set, under the chapter for Flume configuration.
3. University Courseware:
Source: University of California, Berkeley - CS 186/286, Introduction to Database Systems (Big Data Lectures).
Reference: Lecture materials on data ingestion tools often cover the Flume architecture. Slides and notes explain the role of the Source, Channel, and Sink, and specifically highlight the function of the Channel Selector. The Multiplexing Selector is presented as the mechanism for content-based routing, where "content" refers to the event's headers. A typical diagram shows a single source fanning out to multiple channels, with the decision logic based on event.header.get('key').
Location: Course materials for Big Data or Distributed Systems modules, often available publicly through the university's computer science department website.