Empirical Blob Sidecar Hit Rate Based on Local EL’s Mempool

Abstract

This empirical study measures blob sidecar availability in Ethereum's execution layer (EL) mempool to assess the feasibility of distributed block building for reducing validator bandwidth requirements. Analyzing data from both pre- and post-Pectra periods (which increased blob targets from 3 to 6 and maximum from 6 to 9), the researchers found a high empirical blob hit-rate where 76.6% of engine API requests successfully retrieved all requested blob sidecars from the local EL mempool within 100 milliseconds, with 98% of partial responses missing only a single blob sidecar. The study reveals that most blob sidecars are already present in the EL by the time blocks are broadcast on the consensus layer, indicating that the network is currently generating significant redundant traffic in blob propagation. While this redundancy provides resilience, it also represents a bottleneck and inefficiency; the authors recommend exploring alternatives such as shifting blob sharding to the EL layer and implementing a "Blob mempool DHT" proposal to enable more efficient network resource utilization and reduce the time pressure on consensus layer blob broadcasting.