[Ulysses] Add validation for max_num_seqs divisibility by sp_size #234
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Fixes snowflakedb#175 When using Ulysses sequence parallelism, max_num_seqs must be divisible by ulysses_sequence_parallel_size. Previously, using a non-divisible value (e.g., --max-num-seqs=37 with --ulysses-sequence-parallel-size=4) would cause crashes or produce incorrect results. This change adds validation in VllmConfigPatch.__post_init__ that: - Checks if max_num_seqs is divisible by ulysses_sequence_parallel_size - Raises a clear ValueError with suggestions for valid values - Only validates when ulysses_sequence_parallel_size > 1 Also adds comprehensive unit tests for the validation logic. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <[email protected]>
yurekami
requested review from
sfc-gh-jrasley,
sfc-gh-mhidayetoglu,
sfc-gh-reyazda and
sfc-gh-yewang
as code owners
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
Fixes #175
When using Ulysses sequence parallelism,
max_num_seqsmust be divisible byulysses_sequence_parallel_size. Previously, using a non-divisible value (e.g.,--max-num-seqs=37with--ulysses-sequence-parallel-size=4) would cause crashes or produce incorrect results.Changes
_validate_ulysses_config()method inVllmConfigPatchthat validates divisibilityVllmConfig.__post_init__Error Message Example
When a user tries to start with
--max-num-seqs=37 --ulysses-sequence-parallel-size=4:Test plan
ValueErrorsp_size=1skips validation🤖 Generated with Claude Code