2025 Q3 Besu¶

Project Health¶

Besu continues to demonstrate strong project health in Q3 2025, maintaining its position as a critical Ethereum execution client while advancing significant performance and stability improvements. The quarter saw continued focus on block creation reliability, caching optimizations for improved sync performance, and enhancements to the transaction pool management system.

Major Accomplishments This Quarter¶

Performance Under Non-Finality Conditions: A significant achievement in Q3 was the implementation of enhanced caching mechanisms for block headers, specifically designed to improve performance during non-finality conditions. The new --cache-last-block-headers flag allows operators to cache thousands of block headers independently from full block caching, significantly improving sync performance and reducing database load during chain reorganizations.

Block Creation Resilience: The team implemented comprehensive exception handling for block creation, addressing edge cases that previously caused block production failures. This included protection against unexpected runtime exceptions from plugins and internal components, with automatic rollback mechanisms to maintain clean state and continue block production.

Transaction Pool Enhancements: Q3 saw critical improvements to transaction pool management, including better handling of transaction selection timeouts, improved logging for transaction penalization, and separation of executor services for time-critical operations. These changes significantly improved block creation reliability under high load conditions.

Quarterly Release Summary¶

During Q3 2025, the Besu project released:

Besu 25.9.0 (September): Transaction pool optimizations and EthStats compatibility fixes
Additional point releases addressing security vulnerabilities and bug fixes

These releases included over 40 merged pull requests focusing on performance improvements, stability enhancements, and developer experience.

Questions/Issues for the TAC¶

The role of AI : What are other projects doing to define their expectations on how AI is best used?

Releases¶

Major Releases (Q3 2025)¶

25.9.0 - September 2025 - Fixed EthStats integration issues with block access list fields - Enhanced transaction pool executor management for block creation tasks - Improved handling of block creation timeouts before transaction evaluation - Added support for caching block headers during sync operations - Multiple stability improvements for consensus transitions

Point Releases and Patches¶

Multiple point releases were delivered throughout the quarter addressing critical issues, including: - Block creation failures under specific timeout conditions - ArrayIndexOutOfBoundsException during transaction selection - EthStats compatibility with new block structures

Overall Activity in the Past Quarter¶

Community Engagement¶

Discord and GitHub Activity: The Besu community maintained high engagement levels, with particular activity around performance optimization discussions and EIP-7928 implementation. The project saw contributions from new developers, including successful first-time contributions to core functionality.

Documentation and Developer Experience: Continued investment in improving contributor documentation, with specific focus on making complex areas like consensus mechanisms and EVM operations more accessible to new developers.

Cross-Client Collaboration: Active participation in Ethereum All Core Devs calls and coordination on upcoming protocol changes, particularly around block access lists and future hard fork preparations.

Technical Development¶

Performance Optimization Initiative: Significant progress on the performance roadmap, with focus on: - Memory-efficient caching strategies for headers, blocks and blobs - Optimized arithmetic operations for EVM execution - Transaction pool performance under high throughput conditions

Protocol Development: Active work on multiple EIPs: - EIP-7928 (Block Access Lists): Core implementation and testing - Engine API updates for new payload versions - Preparation for future Ethereum protocol upgrades

Enterprise and Private Network Features: Continued enhancements to QBFT consensus, including: - Message handling improvements for networks without direct peer connections - Support for consensus transitions in genesis configuration - Enhanced configuration options for block creation timeouts

Security and Stability¶

Security Response: Prompt addressing of security issues, with no critical vulnerabilities reported in production releases during Q3.

Current Plans¶

Q4 2025 Roadmap¶

EIP-7928 Completion: Finalize Block Access Lists implementation including:

Performance Milestones: Continue advancing toward Gigagas performance targets: - UInt256 arithmetic optimizations for all EVM operations - Serialization improvements via excising Tuweni data types from use.

ERA1 File Support: Complete implementation of ERA1 file export functionality, enabling better archival and data portability options for node operators.

Developer Experience: Focus on tooling and documentation: - Better error messages and logging throughout the codebase

Maintainer Diversity¶

The maintainer diversity challenge continues from Q2, with the project still having 21 active maintainers:

Consensys Software Inc.: 19 maintainers (~95%)
Kaleido: 1 maintainers (~5%)

While organizational diversity among maintainers remains limited, the project has seen increased diversity in contributors, with notable first-time contributions and ongoing participation from various organizations and individual developers.

Active Contributors¶

The project benefits from an expanding contributor base beyond the core maintainer group, with contributions from: - Academic institutions working on performance optimizations - Enterprise users contributing bug fixes and feature enhancements - Individual developers addressing good first issues - Cross-client developers ensuring compatibility

Project Adoption and Usage¶

Public Network Usage¶

Besu maintains its critical role in Ethereum's client diversity, continuing to hold approximately 16% of mainnet stake. This stable market share demonstrates the community's confidence in Besu's reliability and performance.

Institutional Confidence: Major staking providers continue to rely on Besu as part of their multi-client strategies, contributing to overall network resilience.

Enterprise and Private Networks¶

Financial Services Sector: Continued growth in financial services adoption, with institutions leveraging Besu's enterprise features for both pilot projects and production deployments.

Layer 2 Ecosystem: Expanding presence in the Layer 2 space, with Besu components integrated into various rollup infrastructures and serving as the execution layer for multiple scaling solutions.

Government and CBDC Initiatives: Sustained interest from central banks and government entities exploring digital currency solutions, with Besu's performance characteristics and enterprise features making it a preferred choice for proof-of-concept implementations.

This report covers the period July 1 - September 30, 2025. For additional information or clarification on any items in this report, please contact the Besu maintainer team through the project's official channels.