ERPC Releases a Durable Nonce Fanout Operation Guide to Fully Leverage SWQoS for Solana Transaction Submission
ERPC Releases a Durable Nonce Fanout Operation Guide to Fully Leverage SWQoS for Solana Transaction Submission
ERPC, operated by ELSOUL LABO B.V. (Headquarters: Amsterdam, the Netherlands; CEO: Fumitake Kawasaki) and Validators DAO, has released a new practical operation guide that explains how to fully leverage SWQoS (Stake weighted Quality of Service) to achieve both high success rates and low latency in Solana transaction submission.
This guide focuses on transaction submission architectures centered around ERPC’s SWQoS endpoints, and explains how to safely fan out the same transaction to multiple high-performance RPC endpoints. Concrete implementation examples using web3.js are provided, allowing developers to apply the approach directly in real-world environments.
The guide is available at the following URL:
https://erpc.global/en/doc/rpc/durable-nonce-send-transaction/
https://erpc.global/en/doc/rpc/durable-nonce-send-transaction/
Background: Structural Characteristics of Transaction Submission on Solana
In Solana, transaction submission is affected by continuously changing factors such as slot progression, leader scheduling, network routing, and node-level load conditions. As a result, it is not possible to predetermine which submission path will reach the leader the fastest.
This behavior is not caused by the quality of a specific RPC provider or submission service, but is a structural characteristic derived from Solana’s execution model itself. Consequently, designs that rely on a single RPC endpoint tend to face inherent limitations in both transaction success rate and latency.
The Role and Practical Positioning of SWQoS Endpoints
The SWQoS endpoints provided by ERPC enable transactions to be submitted into leader-assigned priority lanes based on Stake weighted Quality of Service. These priority lanes are allocated a significantly larger share of bandwidth (approximately 80%) compared to non-priority lanes (approximately 20%), and are applied at a stage earlier than Priority fee evaluation.
For this reason, SWQoS endpoints represent an important option for submitting high-value transactions. However, in real-world operations, even with SWQoS, a single submission path does not always become the fastest. Within the same slot, transient routing differences and uneven load distribution can allow other high-performance endpoints to process transactions first.
Limitations of Single-Path Designs and the Necessity of Fanout
Given these conditions, it becomes clear that predicting a single fastest path in advance is not an effective design approach. Instead, a fanout strategy—sending the same transaction simultaneously to multiple high-performance submission paths and accepting the one that is processed first—is a rational and robust solution.
By centering on SWQoS while combining it with other fast RPC endpoints, systems can become more resilient to slot-by-slot routing differences and load fluctuations.
Fundamental Challenges in Fanout Operations
At the same time, sending the same transaction across multiple submission paths introduces a critical challenge: without proper control, it is no longer guaranteed that the transaction will be executed only once. Uncontrolled fanout can result in unintended double execution or a breakdown in retry and resend logic.
Preventing these issues purely through application-level logic is difficult, and a protocol-level mechanism is required.
Durable Nonce as the Solution
Solana provides Durable Nonce as an official mechanism to address this problem. By using a nonce value in place of a recentBlockhash, Durable Nonce allows the same signed transaction to be sent across multiple submission paths while ensuring that only a single execution becomes valid on the network.
Durable Nonce therefore serves as a foundational technical component for safely implementing fanout-based transaction submission.
Positioning of This Guide
The newly released guide aims to explain transaction submission using Durable Nonce from an implementation-oriented perspective, rather than a purely theoretical one. It provides a comprehensive explanation of submission design that maximizes the effectiveness of SWQoS endpoints, covering everything from initial setup to daily operational workflows.
Key Topics Covered in the Guide
The guide organizes and explains several operationally critical points, including:
- Design of nonce authority and nonce accounts
- Correct instruction ordering, including nonceAdvance
- Operational constraints regarding the non-reusability of raw transactions
- Parallel submission to multiple RPC endpoints
- Confirmation design assuming Durable Nonce usage
- Safe transition patterns for subsequent transaction submissions
These topics are intended not only for proof-of-concept stages, but also for stable production deployments.
Practical Submission Architectures at ERPC
At ERPC, transaction submission architectures are designed around SWQoS as the core, while combining multiple high-performance RPC endpoints across different regions and routes. Avoiding dependence on a single region or submission path is a critical element of realistic Solana operations.
This guide can be directly applied to practical architectural decision-making in ERPC’s multi-region environment.
Intended Audience
This guide is intended for the following developers and teams:
- Developers handling high-frequency or high-value transactions
- Teams experiencing success rate or latency challenges with existing RPC submission setups
- Users who are already utilizing SWQoS endpoints or considering their adoption
Looking Ahead
ERPC will continue to improve its transaction submission infrastructure, including SWQoS, and will progressively publish operational knowledge gained from real-world deployments in the form of guides and code examples.
ERPC remains committed to supporting developers with a transaction submission platform that is not only fast, but also correct and operationally stable.
Usage and Consultation
For consultation on optimal submission architectures, region selection, or migration from existing designs, individual support is available via the Validators DAO official Discord.
- Validators DAO Official Discord: https://discord.gg/C7ZQSrCkYR
- ERPC Official Website: https://erpc.global/en
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