TimelyDataflow / TimelyDataflow/differential-dataflow

Small batches merge awkwardly

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Dominant language
Rust
Stars
3k
Forks
211
Avg merge
10h 42m
Merged PRs (30d)
34

Description

Because of timely dataflow's restrictions on single capabilities per message, we often end up with several very small batches and one large batch. This can lead to several merges between small and large batches, which is a fairly inefficient way to do things.

Relatively little is known about this, except that we spend a fair bit of time in merging, mostly allocating and dropping random bits of memory. If this is because of lots of skewed merges, we could look into scheduling merges in a different order that works to merge small batches together.

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Research direction

The issue names no files, tests, or entry points. Begin by profiling merge activity and allocation time to determine whether skewed batch sizes are responsible, then investigate whether a different merge order reduces inefficient small-to-large merges.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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