trinodb/trino

DFs received by coordinator are unacked

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#5,429 opened on Oct 6, 2020

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 (2 comments) (0 reactions) (0 assignees)Java (2,678 forks)batch import
good first issue

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Description

Currently, coordinator fetches DF delta between local version and worker version. Coordinator sends it's local version as part of DF request. Worker is free to remove stored DFs based on coordinator local version. However, coordinator does not acknowledge received DFs until next DF is available. Therefore workers can keep DFs locally longer then needed.

This can be resolved by worker artificially bumping DFs version until there are still unacknowledged DFs

Contributor guide

Research direction
Investigate the DF (data fragment) version management between coordinator and worker. Understand how the coordinator's local version is used and why workers do not receive acknowledgements. Look into the codebase for DF request/response handling and version bumping logic.
Tech stack
java
Domain
backenddistributed systemsdatabase
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
JavaDistributed systems
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45