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[lake/lance] add Flink memory usage note#1909

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luoyuxia merged 3 commits into
apache:mainfrom
xx789633:lance_warn
Oct 31, 2025
Merged

[lake/lance] add Flink memory usage note#1909
luoyuxia merged 3 commits into
apache:mainfrom
xx789633:lance_warn

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@xx789633

@xx789633 xx789633 commented Oct 30, 2025

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Purpose

Linked issue: close #xxx

reference:
https://arrow.apache.org/docs/java/memory.html#why-arrow-uses-direct-memory

Brief change log

Tests

API and Format

Documentation


> **NOTE**: Fluss v0.8 only supports tiering log tables to Lance.

> **NOTE**: The Lance connector leverages Arrow Java library, which operates on off-heap memory. To prevent `java.lang.OutOfMemoryError: Direct buffer memory` error in Flink Task Manager, please increase the value of `taskmanager.memory.task.off-heap.size` in `<FLINK_HOME>/conf/config.yaml` to an appropriate size.

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what's the appropriate size? Any suggestion?

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I have updated this to a more concrete suggestion.


> **NOTE**: Fluss v0.8 only supports tiering log tables to Lance.

> **NOTE**: The Lance connector leverages Arrow Java library, which operates on off-heap memory. To prevent `java.lang.OutOfMemoryError: Direct buffer memory` error in Flink Task Manager, please increase the value of `taskmanager.memory.task.off-heap.size` in `<FLINK_HOME>/conf/config.yaml` to an appropriate size.

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what's the appropriate size? Any suggestion?

@luoyuxia luoyuxia requested a review from Copilot October 31, 2025 01:09

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Pull Request Overview

This PR adds a documentation note about configuring off-heap memory for the Lance connector to prevent OutOfMemoryError issues in Flink Task Manager.

  • Adds a new NOTE section explaining the Arrow Java library's off-heap memory requirements
  • Provides guidance on configuring taskmanager.memory.task.off-heap.size to avoid memory errors

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Comment thread website/docs/streaming-lakehouse/integrate-data-lakes/lance.md Outdated
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

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+1

@luoyuxia luoyuxia merged commit 613d354 into apache:main Oct 31, 2025
2 checks passed
wuchong pushed a commit that referenced this pull request Nov 2, 2025
Ugbot pushed a commit to Ugbot/fluss that referenced this pull request Apr 26, 2026
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3 participants