Summary
Chaos Labs provides recommendations for the token rate limit configuration on the Ethereum <> Arbitrum lane.
Motivation
The purpose of configuring a rate limit at this stage is to establish a structure that meets technical, interim, and migrative needs. This involves setting the rate limit based on current user transfer behaviors and the historical clustering of transfer volumes within defined time windows, such that observed user behavior is not hindered during this timeframe while a conservative rate allows the system to provide enough buffer for extreme technical scenarios.
Based on this necessity, to establish the rate limit, the token pool capacity can be set at the 95th percentile of historical GHO cross-chain transfer sizes, which is approximately 300,000 GHO. The refill rate, on the other hand, is calculated by examining GHO bridge volumes within a rolling time window to ensure typical GHO bridge volumes remain unaffected. The accompanying chart illustrates GHO bridge volume percentiles over various rolling windows, showing that maximum bridge volume stabilizes at around 1.5 million GHO between 1.5 and 7 hours of aggregation. This implies that GHO bridging volumes are sporadic, with no more than 1.5 million GHO bridged in aggregate within a 7-hour window.
Consequently, the refill rate can be configured based on the peak bridging volume within a 7-hour window, yielding a per-hour refill rate of 215,000 GHO and a per-second rate of 60 GHO.
Specification
| Lane | Token Pool Rate Limit Capacity | Refill Rate |
|---|---|---|
| Ethereum → Arbitrum | 300,000 | 60 p/s |
| Arbitrum → Ethereum | 300,000 | 60 p/s |