[SAMZA-353] Support assigning the same SSP to multiple tasknames

• Type: Bug
• Status: Reopened
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.8.0
• Component/s: container
• Labels: design
• Assignee: Unassigned
• Reporter: Jakob Homan
• Created: 25/Jul/14 21:32
• Updated: 18/Nov/15 19:24

Description

Post SAMZA-123, it is possible to add the same SSP to multiple tasknames, although currently we check for this and error out if this is done. We should think through the implications of having the same SSP appear in multiple tasknames and support this if it makes sense.

This could be used as a broadcast stream that's either added by Samza itself to each taskname, or individual groupers could do this as makes sense. Right now the container maintains a map of SSP to TaskInstance and delivers the ssp to that task instance. With this change, we'd need to change the map to SSP to Set[TaskInstance] and deliver the message to each TI in the set.

Issue Links

• depends upon: SAMZA-123 Move topic partition grouping to the AM and generalize
• incorporates: SAMZA-676 Implement Broadcast Stream
• is related to: SAMZA-402 Provide a "shared state" store among StreamTasks
• is related to: SAMZA-406 Hot standby containers
• is related to: SAMZA-423 Add document store to Samza
• relates to: SAMZA-569 Make message offsets ordered set within a system stream partition