mimblewimble/grin

Initial txhashset download (request it from a fast peer)

Open

#3083 opened on Oct 4, 2019

View on GitHub
 (1 comment) (0 reactions) (0 assignees)Rust (4,876 stars) (991 forks)batch import
enhancementhelp wanted

Description

Related - #3082 (initial header sync)

If we track "fast" peers during the initial header sync it might make sense to use this information when deciding which peer to request the txhashset.zip from.

This zip file includes the full kernel set and the current UTXO set and is approx 425MB currently.

Right now we arbitrarily choose a random peer to download this zip file from and if we get a slow peer then the initial sync is painfully slow. If we uses some better heuristics we would be far more likely to get "lucky" and download it in a reasonable period of time (and reliably).

Contributor guide

Tech stack
rust
Domain
backendblockchainperformance
Issue type
feature
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.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Familiarity with Grin's peer trackingUnderstanding of initial header sync (issue #3082)Rust programming knowledge
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
Examine the initial header sync implementation in `src/sync/header sync.rs` and how peers are tracked there. Look at the current peer selection logic for downloading txhashset.zip in `src/sync/body sync.rs`. Consider adding a field to track peer download speed and use that to select the fastest peer for the zip download, similar to how header sync tracks fast peers. Test the heuristic with different network conditions.