Prioritization Fee function enabling

[tao-stones]

Problem

User should be able to land their transactions even when leaders are loaded or required write accounts are highly contended, if willing to bid for the access of the limited resources.

This is a subset of #23211 to zoom in Priority Fee function rollout;

Project Transaction Prioritization tracks tasks.

Proposed Solution

Allow users to pay prioritization_fee via compute_budget instruction. The transaction with highest prioritization_fee has highest priority to be considered by leader for block inclusion.

prioritization_fee is defined as micro-lamport per compute-unit that user wants to pay for the transactions. For example, if a transaction's compute_budget instruction specifies priority_fee as 1,000 micro-lamports per cu, and requested_cu as 100,000 CUs, this transaction will be prioritized with 1,000 as priority-fee, and be charged for a priority-fee of (1,000 micro-lamport/cu * 100,000 cu = 0.1 lamport). The priority-fee will be accounted into transaction total-fee (alone with signature fee, write lock fee, compute fee).

This schema encourages dev to request accurate CU (to lower total_fee), and allows users willing to pay to prioritize their transactions.

V0 Rollout Progress

• Rework banking stage to support prioritization of buffered packets, Rework BankingStage to support prioritization of buffered packets #24613

• Banking stage prioritize transactions based on compute_budget instruction's priority-fee, not feature gated. Prioritize transactions in banking stage by their compute unit price #25178 in v1.10.15

• Updated prioritization fee calculations for instructions that use the ComputeBudget::SetComputeUnitPrice instruction. Prioritize transactions in banking stage by their compute unit price #25178 in v1.10.15 (feature gated Feature Gate: Support SetComputeUnitPrice compute budget instruction #25050)

• To avoid forward queue being saturated by transactions to hot accounts, transactions should be forwarded by account bucket in priority order. forward packets by prioritization in desc order #25406

• RPC supports user query for min priority_fee to land transactions in recent blocks, and min priority_fee to write to accounts. Need an RPC api to estimate the fee user should pay #26561

• CLI supports use of priority-fee, Cli support compute_unit_price #26464

• Update docs on how to use this function, update compute budget docs #26014

• Create doc about the fee model as whole, Document the fee model implemented #26615

• Active feature on testnet and devnet

  • Feature Gate: Support SetComputeUnitPrice compute budget instruction #25050

• active feature on mainnet-beta

  • Feature Gate: Support SetComputeUnitPrice compute budget instruction #25050

V1 tasks:

• Add ability to filter transactions pre-sigverify when accounts hit write-compute limit, Add ability to filter transactions pre-sigverify when accounts hit write-compute limit #24657

• High priority transactions should be retried more often, Rework banking_stage retry logic to retry high priority transactions more often #26015

• Add a transaction prioritization API to the JavaScript library (@solana/web3.js), Add a transaction prioritization API to the JavaScript library (@solana/web3.js) solana-web3.js#1099

[bluto658]

Why not alter the transaction model to not only take into account absolute compute, but also if the compute can be parallelized?

[steveluscher]

@taozhu-chicago, would you like to add a task for me here to add a transaction prioritization API to the JavaScript library (@solana/web3.js)?

[tao-stones]

@taozhu-chicago, would you like to add a task for me here to add a transaction prioritization API to the JavaScript library (@solana/web3.js)?

Added, issue solana-labs/solana-web3.js#1099; It is also tracked in project https://github.com/solana-labs/solana/projects/73