[STORM-68] Need multiple output streams for a bolt in Trident

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: storm-core
• Assignee: Unassigned
• Reporter: James Xu
• Created: 14/Dec/13 06:03
• Updated: 09/Oct/15 00:06

Description

https://github.com/nathanmarz/storm/issues/638

Nathan suggested to open an issue for this:

Transactional Topologies gave us the flexibility to have multiple output streams from a bolt from which different downstreamer bolts can subscribe per bolt per stream; while in Trident, though the bolt can take multiple input streams, it is not possible (as per our understanding) to emit different streams. All downstreamer bolts have to subscribe to the same output stream from the bolt.
The only way to solve this in the current system is to tunnel multiple streams in the outgoing stream, which all downstreamers receive and then demultiplex it in each of those bolts and select whatever stream the bolt is interested in. This will have perf implications for our usecases which deals with good amount of traffic.

The discussion:
https://groups.google.com/forum/#!topic/storm-user/G8POD1Hb89I