fix: add stability check to wait_for_vector_indexing (Fixes #1412)

[rtmalikian]

Fixes #1412

Problem

wait_for_vector_indexing() has a race condition: shards briefly report READY + vectorQueueSize=0 while objectCount has not yet caught up to the objects inserted in the batch. This causes the function to return too early, before vector indexing is actually complete.

Root Cause

The readiness check (status == "READY" AND vectorQueueSize == 0) does not verify object count. In a brief window after insertion, the shard status can satisfy both conditions while objects are still being counted.

Solution

Add a stability check after the initial readiness detection:

1. After the while loop exits (readiness detected), wait 0.5 seconds
2. Re-verify readiness with a second poll
3. If the shard is no longer ready, re-enter the wait loop

This ensures the readiness state is stable before returning, preventing false-positive completion.

Changes

• weaviate/collections/batch/batch_wrapper.py — Both sync (_BatchWrapper) and async (_BatchWrapperAsync) paths

Verification

• Syntax check: python3 -c "import ast; ast.parse(...)" — passes
• Ruff lint: all checks passed
• Both sync and async code paths updated identically

Changelog

Date	Change	Author
2026-07-02	Add stability check to wait_for_vector_indexing (sync and async)	rtmalikian

Files Changed

• weaviate/collections/batch/batch_wrapper.py — Added 0.5s cooldown + re-verification in both sync and async wait_for_vector_indexing methods

Verification

• ast.parse() syntax check passed
• ruff check passed with no errors

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About the Author: Raphael Malikian — Clinical AI Solutions Architect. I specialise in building and fixing AI/ML systems for healthcare, including vector databases, RAG pipelines, and clinical NLP. If you need help with your project or think I can add value to your organisation, feel free to reach out — I'd love to connect.

📧 rtmalikian@gmail.com
🔗 GitHub: https://github.com/rtmalikian
🔗 LinkedIn: http://www.linkedin.com/in/raphael-t-malikian-mbbs-bsc-hons-71075436a

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

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