[SAMZA-2179] Move the StartpointVisitor abstraction to SystemAdmin interface.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2
• Assignee: Shanthoosh Venkataraman
• Reporter: Shanthoosh Venkataraman
• Created: 30/Apr/19 00:47
• Updated: 17/May/19 19:23
• Resolved: 17/May/19 19:23

Description

This patch is comprised of the following changes:

• Migrates the `StartpointVisitor` abstraction from `SystemConsumer` to `SystemAdmin`. Currently, startpoints are acted upon at the `SystemConsumer` layer. This patch enables resolving startpoint to the offset before starting off the downstream components of SamzaContainer. This provides easier integration path for Startpoint by not mandating that every component of SamzaContainer from OffsetManager, SystemConsumer, SystemConsumers etc to support startpoint semantics and avoids proliferation of Samza public API with startpoints.
• Moves the `KafkaStartpointVisitor` implementation from `KafkaSystemConsumer` to `KafkaSystemAdmin`. Reverts back the refactor done in `KafkaSystemConsumer` for startpoints.
• Moved the startpoint tests from `KafkaSystemConsumer` to `KafkaSystemAdmin`.
• Removes the `StartpointCustom`, which is not required for supporting any type of seek-back for I/O connectors.

Issue Links

• links to: GitHub Pull Request #1016