feat: consider tenure block fullness for transaction fee estimations

[rafaelcr]

Modifies the Stacks core fee estimator proxy to follow this algorithm:

• If the current and recent tenure costs are not full, always return the minimum transaction fee
• If tenures start receiving transactions but do not yet reach a 90% fullness in any dimension, keep returning the minimum fee
• Once a dimension exceeds 90% based on a weighted average of past tenures, use the Stacks core estimation (with a configured multiplier)
• If at any time the current tenure has at least 5 blocks and less than 50% utilization, return to minimum fees

All previous numbers are configurable via ENV:

# Enables the enhanced transaction fee estimator that will alter results for `POST
# /v2/fees/transaction`.
STACKS_CORE_FEE_ESTIMATOR_ENABLED=0

# Multiplier for all fee estimations returned by Stacks core. Must be between 0.0 and 1.0.
STACKS_CORE_FEE_ESTIMATION_MODIFIER=1.0

# How many past tenures the fee estimator will look at to determine if there is a fee market for
# transactions.
STACKS_CORE_FEE_PAST_TENURE_FULLNESS_WINDOW=5

# Percentage at which past tenure cost dimensions will be considered "full".
STACKS_CORE_FEE_PAST_DIMENSION_FULLNESS_THRESHOLD=0.9

# Percentage at which current cost tenures will be considered "busy" in order to determine if we
# should check previous tenures for a fee market.
STACKS_CORE_FEE_CURRENT_DIMENSION_FULLNESS_THRESHOLD=0.5

# Minimum number of blocks the current tenure must have in order to check for "busyness".
STACKS_CORE_FEE_CURRENT_BLOCK_COUNT_MINIMUM=5

[codecov]

Codecov Report

Attention: Patch coverage is 88.07339% with 13 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/api/routes/core-node-rpc-proxy.ts	85.71%	13 Missing ⚠️

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[github-actions]

Vercel deployment URL: https://stacks-blockchain-qurhv694h-hirosystems.vercel.app 🚀

[diwakergupta]

How are you testing this @rafaelcr ?

[rafaelcr]

Thanks for the review @diwakergupta !

How are you testing this @rafaelcr ?

Once logic is verified by Brice/core team I will add unit tests simulating different tenure fullness scenarios. Once merged, we'll follow the same procedure we did for the initial fee estimation proxy (deploy to testnet and validate before moving deployment to mainnet)

[obycode]

This looks good. I noted a couple of thoughts.

It may also be nice to take the current tenure into account, so that it would react quickly when the traffic dies down after a surge. This could be something really simple/naive like, if the current tenure has at least 5 blocks and all cost dimensions are < 50% of the limit, then use the min fee.

[rafaelcr]

@obycode @diwakergupta can you take another look? Easiest is to follow the unit test scenarios starting here: https://github.com/hirosystems/stacks-blockchain-api/pull/2203/files#diff-22bb01d2b4337f97428b33c9aed8d5d87611b43381a61b04611f26606f50c94fR203

Thanks

[obycode]

I'll leave the details of the SQL queries for someone else to review, but everything else looks great!

[obycode]

What do you think about always including the minimum fee in this response, along with the estimated fee, so that wallets could easily include that in their UI? I think this would be nice from a user perspective, if I have a low priority transaction that I'd like to get included whenever, I just want to pay the min fee.

[rafaelcr]

@obycode that's a good idea. Would this be the first value of the 3 estimations returned by core? (it always returns an array of 3 estimations)

[obycode]

@obycode that's a good idea. Would this be the first value of the 3 estimations returned by core? (it always returns an array of 3 estimations)

Looks like it is just "low", "medium", and "high", but low is not necessarily the minimum fee, but I think it could be fine if we just take over the "low" for this minimum value. I guess we should check with the wallets.

[rafaelcr]

@obycode sounds good. I think we can make that tweak in a next PR once we've touched base with them.

[blockstack-devops]

🎉 This PR is included in version 8.6.0-beta.1 🎉

The release is available on:

• npm package (@beta dist-tag)
• GitHub release

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[blockstack-devops]

🎉 This PR is included in version 8.6.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀