multi: Implement DCP0010 subsidy consensus vote. #2848

davecgh · 2021-12-13T11:11:07Z

This requires #2847.

This implements the agenda for voting on the modified subsidy split defined in DCP0010 along with consensus tests.

In particular, once the vote has passed and is active, the PoW subsidy will be 10% of the block reward and the PoS subsidy will be 80%. The Treasury subsidy will remain at 10%.

In terms of the overall effects, this includes updates to:

The validation logic for votes, coinbases, and overall block subsidy
Enforcement when considering candidate votes for acceptance to the mempool, relaying, and inclusion into block templates
Mining template generation
The output of the getblocksubsidy RPC

Also note that this does not implement the block version bump that will ultimately be needed by the mining code since there are multiple consensus votes gated behind it and will therefore be done separately.

The following is an overview of the changes:

Introduce a convenience function for determining if the vote passed and is now active
Add new methods to blockchain/standalone for calculating the work and stake vote subsidies according to either the original or modified values per a provided flag
Modify vote validation to enforce the new stake vote subsidy in accordance with the state of the vote
Modify coinbase validation to enforce the new work subsidy in accordance with the state of the vote
Modify block validation logic to enforce the total overall subsidy in accordance with the state of the vote
Add tests for determining if the agenda is active for both mainnet and testnet
Add tests for getblocksubsidy RPC
Add tests to ensure proper behavior for the modified subsidy splits as follows:
- Ensure new blockchain validation semantics are enforced once the agenda is active
- Ensure mempool correctly accepts and rejects votes in accordance with the state of the vote

blockchain/standalone/subsidy.go

blockchain/standalone/subsidy_test.go

matheusd · 2021-12-14T13:46:27Z

blockchain/standalone/subsidy_test.go

+	}
+
+	// Ensure the total calculated subsidy is the expected value.
+	const expectedTotalSubsidy = 2100000000015952


So the net result is an increase in total issuance of 215k atoms.

Estimated. Yes. The reason is that fewer atoms are lost due to truncation.

rstaudt2

Going to do more testing and another thorough review, but so far, everything is looking good to me.

blockchain/agendas_test.go

blockchain/standalone/subsidy.go

rstaudt2 · 2021-12-14T17:38:33Z

blockchain/validate.go

+			// Subsidy aligns with the height being voting on, not with the
+			// height of the current block.
+			voteSubsidy := b.subsidyCache.CalcStakeVoteSubsidyV2(node.height-1,
+				isSubsidySplitEnabled)


I double-checked and confirmed that there are no other locations using the CalcWorkSubsidy or CalcStakeVoteSubsidy versions of these functions (other than tests and internally to the subsidy code).

internal/mining/mining.go

dnldd

Will run some simnet tests later, looking good overall.

dnldd · 2021-12-15T09:03:44Z

Can't mine past SVH on simnet so far. Getting this error from the wallet.

2021-12-15 08:59:00.823 [ERR] WLLT: Failed to send one or more votes: dcrd.PublishTransactions: rejected transaction ef0e9658ef997c1ec41c2781a52281b45124f038a1be325dbdc6795bbb70fb90: vote subsidy input value of 2970297029 is not 7920792079

davecgh · 2021-12-15T09:05:36Z

Can't mine past SVH on simnet so far. Getting this error from the wallet.

Yes, that is expected because the agenda is active and your wallet isn't updated to calculate the new required vote subsidy. You'll either have to wait for wallet to be updated or just modify it yourself to call the new methods with the agenda active.

dnldd · 2021-12-15T09:06:27Z

Thought as much, thanks. Will update the wallet.

davecgh · 2021-12-15T17:07:49Z

I updated the first commit to include a few more tests so it includes all of the test vectors that are in the DCP.

blockchain/standalone/subsidy_test.go

chappjc · 2021-12-15T17:34:18Z

blockchain/thresholdstate.go

+	deploymentVer, ok := b.deploymentVers[deploymentID]
+	if !ok {
+		return true, nil


This looks like boilerplate from the other methods, but I'm not clear what this implies. Not found means it was not in chaincfg.Params.Deployments, which means:

"voting is not enabled for this network" as described in isLNFeaturesAgendaActive. Like simnet where it is always active?

This deployment is ancient history, removed from Params.Deployments, and thus passed? Presumably the plan is if an agenda fails then all the related code that would look for it would also be removed if it is also removed from Params.Deployments.

Yes on number 1. For number 2, in the case of failure, yes, that's correct. In the case of success though, the idea is that the code would be changed so that the historical activation points for mainnet/testnet are added and then these methods would turn into "if that historical activation point is an ancestor of a given block, it's active, otherwise, it's not".

EDIT: I should also note that Matheus and I have discussed previously that it would probably be nicer to add a flag to the deployments for specifying whether or not it should always be considered active instead of the current approach of "active if voting is not enabled for this network due to lack of a definition for the deployment". I am planning to do that at some point.

This adds two new exported functions to the subsidy cache in blockchain/standalone to calculate calculate the work and stake vote subsidies according to either the original or modified values defined in DCP0010 per a provided flag along with tests to ensure expected behavior. It should be noted that the values for the modified split are hard coded as opposed to using the subsidy in order to avoid the need for a major module bump that would be required if the subsidy params interface were changed. The values are the same for all networks, so no additional logic is necessary on a per-network basis.

This adds a new munger to the test chain generator named ReplaceVoteSubsidies which modifies a block by replacing the subsidy of all votes contained in the block to a given value.

davecgh · 2021-12-16T01:32:49Z

Updated to remove the replace for chaincfg/v3 in favor of chaincfg/v3.1.1 now that is has been tagged.

rstaudt2

In addition to giving this another thorough review, I also tested the following scenarios in simnet (with dcrd updated to activate the agenda at a particular height and dcrwallet updated to use CalcStakeVoteSubsidyV2):

When the agenda is NOT active
- Votes are accepted with the original vote subsidy
- Votes are NOT accepted with the new vote subsidy (and therefore, blocks can't be mined)
- Blocks are NOT accepted with the new work subsidy (modified the mining code to test)
- Blocks are accepted with the original vote and work subsidy
When the agenda is active
- Votes are NOT accepted with the original vote subsidy (and therefore, blocks can't be mined)
- Votes are accepted with the new vote subsidy
- Blocks are NOT accepted with the original work subsidy (modified the mining code to test)
- Blocks are accepted with the new vote and work subsidy
Validated that disconnecting and reconnecting blocks across the agenda activation height works as expected

Looks good to me!

internal/mempool/mempool_test.go

This implements the agenda for voting on the modified subsidy split defined in DCP0010 along with consensus tests. In particular, once the vote has passed and is active, the PoW subsidy will be 10% of the block reward and the PoS subsidy will be 80%. The Treasury subsidy will remain at 10%. In terms of the overall effects, this includes updates to: - The validation logic for votes, coinbases, and overall block subsidy - Enforcement when considering candidate votes for acceptance to the mempool, relaying, and inclusion into block templates - Mining template generation - The output of the getblocksubsidy RPC Also note that this does not implement the block version bump that will ultimately be needed by the mining code since there are multiple consensus votes gated behind it and will therefore be done separately. The following is an overview of the changes: - Introduce a convenience function for determining if the vote passed and is now active - Add new methods to blockchain/standalone for calculating the work and stake vote subsidies according to either the original or modified values per a provided flag - Modify vote validation to enforce the new stake vote subsidy in accordance with the state of the vote - Modify coinbase validation to enforce the new work subsidy in accordance with the state of the vote - Modify block validation logic to enforce the total overall subsidy in accordance with the state of the vote - Add tests for determining if the agenda is active for both mainnet and testnet - Add tests for getblocksubsidy RPC - Add tests to ensure proper behavior for the modified subsidy splits as follows: - Ensure new blockchain validation semantics are enforced once the agenda is active - Ensure mempool correctly accepts and rejects votes in accordance with the state of the vote

This updates the simnet environment documentation to account for the different expected initial balances due to the subsidy split agenda since it is always active on simnet.

matheusd

Tested on simnet. Woop!

dnldd

Simnet testing looks good.

davecgh added this to the 1.7.0 milestone Dec 13, 2021

davecgh force-pushed the multi_dcp0010_subsidy_split branch 3 times, most recently from db87955 to b249403 Compare December 13, 2021 21:05

davecgh added the consensus changes Changes that involve modifying the consensus rules and thus are required to be gated behind a vote. label Dec 13, 2021

davecgh force-pushed the multi_dcp0010_subsidy_split branch 2 times, most recently from 999c545 to 923bc6a Compare December 14, 2021 06:23

davecgh changed the title ~~WIP: multi: Implement DCP0010 subsidy consensus vote.~~ multi: Implement DCP0010 subsidy consensus vote. Dec 14, 2021

davecgh marked this pull request as ready for review December 14, 2021 06:24

matheusd reviewed Dec 14, 2021

View reviewed changes

rstaudt2 reviewed Dec 14, 2021

View reviewed changes

davecgh force-pushed the multi_dcp0010_subsidy_split branch from 923bc6a to 01cd66f Compare December 14, 2021 18:29

dnldd reviewed Dec 14, 2021

View reviewed changes

davecgh force-pushed the multi_dcp0010_subsidy_split branch from 01cd66f to ba03567 Compare December 15, 2021 00:15

davecgh force-pushed the multi_dcp0010_subsidy_split branch from ba03567 to 5351006 Compare December 15, 2021 09:20

chappjc reviewed Dec 15, 2021

View reviewed changes

davecgh added 2 commits December 15, 2021 12:07

chaingen: Add vote subsidy munger.

c4d1094

This adds a new munger to the test chain generator named ReplaceVoteSubsidies which modifies a block by replacing the subsidy of all votes contained in the block to a given value.

davecgh force-pushed the multi_dcp0010_subsidy_split branch 2 times, most recently from a858c16 to ec0736c Compare December 16, 2021 01:31

rstaudt2 approved these changes Dec 16, 2021

View reviewed changes

internal/mempool/mempool_test.go Outdated Show resolved Hide resolved

davecgh added 2 commits December 16, 2021 12:26

docs: Update simnet env docs for subsidy split.

259b51b

This updates the simnet environment documentation to account for the different expected initial balances due to the subsidy split agenda since it is always active on simnet.

davecgh force-pushed the multi_dcp0010_subsidy_split branch from ec0736c to 259b51b Compare December 16, 2021 18:26

matheusd approved these changes Dec 16, 2021

View reviewed changes

dnldd approved these changes Dec 17, 2021

View reviewed changes

davecgh merged commit 259b51b into decred:master Dec 17, 2021

davecgh deleted the multi_dcp0010_subsidy_split branch December 17, 2021 19:25

davecgh mentioned this pull request Feb 15, 2023

Feature Request: Allow forcing a vote result in network parameters. #3058

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

multi: Implement DCP0010 subsidy consensus vote. #2848

multi: Implement DCP0010 subsidy consensus vote. #2848

davecgh commented Dec 13, 2021 •

edited

matheusd Dec 14, 2021

davecgh Dec 14, 2021 •

edited

rstaudt2 left a comment

rstaudt2 Dec 14, 2021

dnldd left a comment

dnldd commented Dec 15, 2021 •

edited

davecgh commented Dec 15, 2021 •

edited

dnldd commented Dec 15, 2021

davecgh commented Dec 15, 2021

chappjc Dec 15, 2021

davecgh Dec 15, 2021 •

edited

davecgh commented Dec 16, 2021

rstaudt2 left a comment

matheusd left a comment

dnldd left a comment

multi: Implement DCP0010 subsidy consensus vote. #2848

multi: Implement DCP0010 subsidy consensus vote. #2848

Conversation

davecgh commented Dec 13, 2021 • edited

matheusd Dec 14, 2021

Choose a reason for hiding this comment

davecgh Dec 14, 2021 • edited

Choose a reason for hiding this comment

rstaudt2 left a comment

Choose a reason for hiding this comment

rstaudt2 Dec 14, 2021

Choose a reason for hiding this comment

dnldd left a comment

Choose a reason for hiding this comment

dnldd commented Dec 15, 2021 • edited

davecgh commented Dec 15, 2021 • edited

dnldd commented Dec 15, 2021

davecgh commented Dec 15, 2021

chappjc Dec 15, 2021

Choose a reason for hiding this comment

davecgh Dec 15, 2021 • edited

Choose a reason for hiding this comment

davecgh commented Dec 16, 2021

rstaudt2 left a comment

Choose a reason for hiding this comment

matheusd left a comment

Choose a reason for hiding this comment

dnldd left a comment

Choose a reason for hiding this comment

davecgh commented Dec 13, 2021 •

edited

davecgh Dec 14, 2021 •

edited

dnldd commented Dec 15, 2021 •

edited

davecgh commented Dec 15, 2021 •

edited

davecgh Dec 15, 2021 •

edited