Historical Updates¶

Introduction¶

This page overviews historical updates on Moonbeam and Moonriver, such as bug fixes to the Moonbeam source code and data migrations applied.

This page aims to provide information about unexpected behaviors or data inconsistencies associated with updates that require forced data migrations.

Bugs¶

Invalid Transactions Stored¶

For invalid transactions where the transaction cost couldn't be paid, the EVM pallet inserted the transaction metadata into storage instead of discarding it because there was no transaction cost validation. As a result, the runtime storage was unnecessarily bloated with invalid transaction data.

This bug only impacted Moonriver and Moonbase Alpha and existed during the following runtimes and block ranges:

For more information, you can review the relative Frontier PR on GitHub.

Ethereum Fees Weren't Sent to Treasury¶

The Moonbeam fee model for transactions allocates 20% of the fees to the on-chain Treasury and burns 80% as a deflationary force. Before runtime 800, Ethereum transactions did not allocate 20% of the transaction fees to the on-chain Treasury.

This bug only impacted Moonriver and Moonbase Alpha and existed during the following runtimes and block ranges:

For more information, you can review the relative PR on GitHub.

Missing Refunds¶

Moonbeam is configured to set the existential deposit to 0, meaning that accounts do not need a minimum balance to be considered active. For Substrate-based chains with this configuration, some refunds were missing from zeroed accounts because the account was interpreted as not existing.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative Frontier PR and the associated Substrate PR on GitHub.

Incorrect Collator Selection¶

The total delegations for collator candidates were not correctly updated when a delegation was increased via the delegatorBondMore extrinsic. This led to issues where the increased delegation amount wasn't included in the candidates' total amount bonded, which is used to determine which candidates are in the active set of collators. As a result, some candidates may not have been selected to be in the active set when they should have been, impacting their own and their delegators' rewards.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative PR on GitHub.

New Account Event Bug¶

The System.NewAccount event is emitted when a new account is created. However, a bug prevented this event from being emitted for some accounts at creation time. A hotfix was applied that patched the impacted accounts and emitted the System.NewAccount at a later time.

The hotfix was applied in the following block ranges:

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative Frontier PR on GitHub.

Incorrect Timestamp Units¶

EIP-2612 and Ethereum blocks deal with timestamps in seconds; however, the Substrate timestamp pallet that Moonbeam implements uses milliseconds. This only affected the EIP-2612 implementation, not the block.timestamp value.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative PR on GitHub.

Substrate Tips Missing Treasury Distribution¶

Tips for Substrate-based transactions weren't handled properly. The entire portion of the tip was burned because it was not handled in the runtime code. A fix was applied so that 20% is paid to the Treasury and 80% is burned, consistent with all other fee behavior.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative PR on GitHub.

Incorrect Delegation Reward Calculation¶

The reward payouts for all delegations and collators were underestimated whenever there were pending requests. Delegation rewards are calculated based on the amount of tokens bonded by each delegator with respect to the total stake of the given collator. By counting delegation amounts for pending requests, the rewards to collators and their delegations were less than they should have been.

This bug existed during the following runtimes and block ranges:

You can review the relative PR on GitHub for more information.

Block Parent Hash Calculated Incorrectly¶

After EIP-1559 support was introduced, which included the transition to new Ethereum transaction types, the block header parent hash was miscalculated to H256::default.

This bug only impacted Moonbase Alpha and only impacted the following block:

While the root issue was fixed in RT1201, the incorrect hash was corrected in RT2601.

For more information on the root fix, you can review the relative Frontier PR on GitHub. To take a look at the correction of the parent hash, check out the corresponding Moonbeam PR on GitHub.

Incorrect Handling of EIP-1559 Gas Fees¶

With the introduction of EIP-1559 support, the logic for handling maxFeePerGas and maxPriorityFeePerGas was implemented incorrectly. As a result, the maxPriorityFeePerGas was added to the baseFee even if the total amount was over the maxFeePerGas.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative Frontier PR.

Transaction Fees Paid to Collators¶

For blocks that included EIP-1559 transactions where a priority fee was applied, the transaction fees were incorrectly calculated and distributed to the block's collator. The fee model on Moonbeam for transactions and smart contract execution is handled so that 20% of the fees go to the on-chain Treasury and 80% are burned as a deflationary force. Due to this bug, the transaction fees of the impacted transactions were not burned as expected.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative PR on GitHub.

Incorrect State Root Hash¶

The state root hash was miscalculated for non-legacy transactions as the transaction-type byte was not considered. With the support of EIP-2930 and EIP-1559, the transaction types introduced are 0x01 (1) and 0x02 (2), respectively. These transaction types were omitted from the state root hash calculation.

This bug existed during the following runtimes and block ranges:

For more information, you can review the relative Frontier PR and Moonbeam PR on GitHub.

Ethereum Transactions Duplicated in Storage¶

An upstream bug was introduced to Frontier in the Ethereum Pallet, causing pending transactions that existed during a runtime upgrade to be duplicated in storage across two different blocks. This only impacted the first two blocks after the runtime upgrade in which this bug was introduced.

Only Moonriver and Moonbase Alpha were impacted. The bug was introduced in the following runtimes and affected the following blocks:

The following transactions were duplicated:

'0x2cceda1436e32ae3b3a2194a8cb5bc4188259600c714789bae1fedc0bbc5125f',
'0x3043660e35e89cafd7b0e0dce9636f5fcc218fce2a57d1104cf21aabbff9a1c0',
'0x514411fb5c08f7c5aa6c61c38f33edfa74ff7e160831f6140e8dd3783648dbca',
'0xf1647c357d8e1b05c522d11cff1f5090a4df114595d0f4b9e4ac5bb746473eea',
'0x4be94803fe7839d5ef13ddd2633a293b4a7dddbe526839c15c1646c72e7b0b23',
'0x15fceb009bd49692b598859f9146303ed4d8204b38e35c147fcdb18956679dbe',
'0xa7460d23d5c633feec3d8e8f4382240d9b71a0d770f7541c3c32504b5403b70c',
'0x1c838b4c4e7796a9db5edfd0377aee6e0d89b623bf1d7803f766f4cf71daefb9',
'0xfb233a893e62d717ed627585f14b1ee8b3e300ac4e2c3016eb63e546a60820f0',
'0xfaf8908838683ad51894eb3c68196afb99ba2e2bb698a40108960ee55417b56a',
'0xa53973acbeac9fe948015dcfad6e0cb28d91b93c8115347c178333e73fd332d3',
'0x9df769c96c5fdd505c67fee27eaff3714bf8f3d45a2afc02dd2984884b3cecac',
'0x8f912ae91b408f082026992a87060ed245dac6e382a84288bd38fc08dbac30fe',
'0xb22af459d24cb25bc53785bdd0ae6a573e24f226c94fd8d2e4663b87d3b07a88',
'0x8ab9cd2bde7d679f798528b0c75325787f5fc7997e00589445b35b3954a815aa',
'0xd08a1f82f4d3dc553b4b559925f997ef8bb85cb24cb4d0b893f017129fb33b78',
'0xa1d40bce7cc607c19ca4b37152b6d8d3a408e3de6b9789c5977fcdef7ef14d97',
'0xe442227634db10f5d0e8c1da09f8721c2a57267edbf97c4325c4f8432fd48ade',
'0x0b4f5d8338a7c2b1604c1c42e96b12dc2a9d5ab264eb74ff730354e9765de13f',
'0x0b00fc907701003aad75560d8b1a33cbf4b75f76c81d776b8b92d20e1d2e9d31',
'0x9c18bd783f28427d873970ff9deaf1549db2f9a76e3edd6bdeae11358e447ef4',
'0x8b2523f163989969dd0ebcac85d14805756bc0075b89da1274fd2c53ccaa396a',
'0x47e80a0c533265974a55ea62131814e31b10f42895709f7e531e3e7b69f1387c'

'0x006a6843eb35ad35a9ea9a99affa8d81f1ed500253c98cc9c080d84171a0afb3',
'0x64c102f664eb435206ad4fcb49b526722176bcf74801c79473c3b5b2c281a243',
'0xf546335453b6e35ce7e236ee873c96ba3a22602b3acc4f45f5d68b33a76d79ca',
'0x4ed713ccd474fc33d2022a802f064cc012e3e37cd22891d4a89c7ba3d776f2db',
'0xa5355f86844bb23fe666b10b509543fa377a9e324513eb221e0a2c926a64cae4',
'0xc14791a3a392018fc3438f39cac1d572e8baadd4ed350e0355d1ca874a169e6a'

The duplicated transactions belong to the first block. So, on Moonriver, the transactions belong to block 2077599, and on Moonbase Alpha, the impacted transactions belong to block 2285347.

For more information, you can review the relative Frontier PR on GitHub.

Gas Limit Too High for Non-Transactional Calls¶

When a non-transactional call, such as eth_call or eth_estimateGas, is made without specifying a gas limit for a past block, the client defaults to using the gas limit multiplier (10x), which causes the gas limit validation to fail as it is validating against an upper bound of the block gas limit. So, if the gas limit is greater than the block gas limit for a given call, a gas limit too high error is returned.

This bug existed during the following runtimes and block ranges:

You can review the relative Frontier PR on GitHub for more information.

Remote EVM Calls Return Identical Transaction Hashes¶

When multiple remote EVM calls were sent from different accounts with the same transaction payload and nonce, the same transaction hash was returned for each call. This was possible because remote EVM calls are executed from a keyless account, so if the senders all had the same nonce and were sending the same transaction object, there was no differentiation in the calculation of the transaction hash. This was fixed by adding a global nonce to the Ethereum XCM Pallet, which is the pallet that makes remote EVM calls possible.

This bug only existed on Moonbase Alpha during the following runtimes and block ranges:

You can review the relative PR on GitHub for more information.

Gas Estimation Discrepancy¶

There was a difference between estimating the gas for a transaction using a non-transaction call, such as eth_call, and the execution of it on-chain. The discrepancy occurred because the non-transactional calls were not properly accounting for maxFeePerGas and maxPriorityFeePerGas, as such, the (Proof of Validity) consumed by the Ethereum transaction was counted differently. This was fixed by properly accounting for these fields when estimating the size of the on-chain transaction.

This bug existed during the following runtimes and block ranges:

You can review the relative PR on GitHub for more information.

Incorrect Effective Gas Price In Transaction Receipts¶

The effectiveGasPrice value returned by eth_getTransactionReceipt was different from the on-chain value due to an incorrect calculation of the base fee. Specifically, the transaction receipt's value was computed using the NextFeeMultiplier from the block in which the transaction was included rather than the previous block, which is the correct source for computing the base fee.

This bug existed during the following runtimes and block ranges:

You can review the relative Frontier PR and Moonbeam PR on GitHub for more information.

Migrations¶

Migrations are necessary when a storage item is changed or added and needs to be populated with data. The migrations listed below have been organized by the impacted pallet(s).

Author Mapping Pallet¶

Update the Mapping Storage Item¶

This migration updated the now deprecated Mapping storage item of the author mapping pallet to use a more secure hasher type. The hasher type was updated to Blake2_128Concat instead of Twox64Concat.

This migration was only applied to Moonriver and Moonbase Alpha and was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Add Support for VRF Keys¶

When VRF key support was introduced, the MappingWithDeposit storage item of the author mapping pallet was updated to include a keys field to support VRF keys that can be looked up via the Nimbus ID. A migration was applied to update the existing storage items with this new field.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

One Nimbus ID per Account ID¶

A migration was applied to ensure that an account ID can have only one Nimbus ID. The migration accepted the first Nimbus ID owned by a given account and cleared any additional Nimbus IDs associated with the account. For any cleared associations, the bond for the association was returned.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Base Fee Pallet¶

Set Elasticity Storage Item Value¶

This migration sets the Elasticity storage item of the base fee pallet to zero, which results in a constant BaseFeePerGas.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Democracy Pallet¶

Preimage Storage Moved to New Preimage Pallet¶

A migration was applied, which moved preimages stored in the democracy pallet to a new preimage pallet. This migration on Moonbeam was required as a result of an upstream change to Polkadot.

There was one preimage that was affected in Moonbeam, which was dropped from the scheduler queue and never executed: 0x14262a42aa6ccb3cae0a169b939ca5b185bc317bb7c449ca1741a0600008d306. This preimage was manually removed by the account that initially submitted the preimage.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Remove Governance V1 Collectives¶

A migration was applied to remove the governance V1 collectives, which included the Council and Technical Committee. The governance V1 collectives were replaced with the OpenGov (governance V2) Technical Committee.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

A follow-up migration was required to properly clear the storage entries associated with the governance V1 collectives, which was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Remove Governance V1 Democracy Pallet¶

A migration was applied to remove the storage associated with the Democracy Pallet used in governance V1. The Democracy Pallet was replaced with the Preimage, Referenda, and Collective Voting OpenGov (governance V2) pallets.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Moonbeam Orbiter Pallet¶

Remove the Minimum Bond Requirement for Orbiter Collators¶

A migration was applied to the Moonbeam Orbiter Pallet that sets the bonds of the existing orbiter collators to zero. This change enabled payouts to be even for future orbiter program expansions.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Parachain Staking Pallet¶

Update Collator State Storage Item¶

A migration was applied that updated the Collator storage item of the parachain staking pallet to the new Collator2 storage item. This change updated the collator state to include the following items:

• The nominators set is a list of all of the nominator (delegator) account IDs without their respective balance bonded
• A new top_nominators storage item that returns a list of all of the top nominators ordered by greatest bond amount to least
• A new bottom_nominators storage item that returns a list of all of the bottom nominators ordered by least bond amount to greatest
• The total storage item was replaced with total_counted and total_backing. The total_counted item returns the sum of the top nominations and the collator's self-bond, whereas the total_backing item returns the sum of all of the nominations and the collator's self-bond

This migration was only applied to Moonriver and Moonbase Alpha and was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Patch Total Staked Amount¶

A migration was applied to the total staked amount of the CollatorState storage item in the Parachain Staking Pallet due to a potential bug that may have led to an incorrect amount.

This migration was only applied to Moonriver and Moonbase Alpha and was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Support Delayed Nominator (Delegator) Exits¶

The exit queue for handling candidate exits had been updated to include support for delayed nominator (delegator) exits and revocations, which required a migration to update the ExitQueue parachain staking pallet storage item to ExitQueue2. The NominatorState storage item was also migrated to NominatorState2 to prevent a nominator from performing more nominations when they already have scheduled an exit.

These migrations were only applied to Moonriver and Moonbase Alpha and were executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Purge Staking Storage Bloat¶

A migration was applied to purge staking storage bloat for the Points and AtStake storage items of the parachain staking pallet that are older than two rounds.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Support Manual Exits and DPoS Terminology¶

The parachain staking pallet was updated to include manual exits. If a candidate or delegator wanted to decrease or revoke their bond or leave the candidate or delegator pool, they would need to schedule a request first, wait for a delay period to pass, and then manually execute the request. As such, a migration was applied to replace the automatic exit queue, including the ExitQueue2 storage item, with a manual exits API.

In addition, a change was made to switch from Nominated Proof of Stake (NPoS) to Delegated Proof of Stake (DPoS) terminology; this marked the sweeping change from "nominate" to "delegate". This required the migration of the following parachain staking pallet storage items:

• CollatorState2 was migrated to CandidateState
• NominatorState2 was migrated to DelegatorState

These migrations were executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Increase Max Delegations per Candidate¶

A migration was applied to increase the maximum number of delegations per candidate in the parachain staking pallet. It increased the delegations from 100 to 500 on Moonbase Alpha and Moonriver and from 100 to 1000 on Moonbeam.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Split Candidate Delegations into Top and Bottom¶

This migration splits the deprecated CandidateState storage item of the parachain staking pallet into the following three new storage items to avoid unnecessary storage reads:

• CandidateInfo
• TopDelegations
• BottomDelegations

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Patch Incorrect Total Delegations¶

There was a migration applied to fix the Incorrect Collator Selection bug and patch the delegations total for all candidates.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Split Delegator State into Delegation Scheduled Requests¶

A migration was applied that moved pending delegator requests from the DelegatorState storage item of the parachain staking pallet into a new DelegationScheduledRequests storage item.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Replace Staking Reserves with Locks¶

A migration was applied that changed users' staking reserved balances to locked balances. The locked balance is the same type as democracy-locked funds, allowing users to use their staked funds to participate in democracy.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Auto-Compounding Support¶

To support auto-compounding, two migrations were applied to the AtStake storage item in the parachain staking pallet:

• RemovePaidRoundsFromAtStake - to remove any stale AtStake entries relating to already paid-out rounds with candidates that didn't produce any blocks. This migration is a prerequisite for the MigrateAtStakeAutoCompound migration
• MigrateAtStakeAutoCompound - migrates the snapshots for unpaid rounds for AtStake entries

These migrations were executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Switch to Block-Based Staking Rounds¶

A migration was applied to switch from time-based staking rounds to fixed block-based rounds.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Referenda Pallet¶

A migration was introduced to support refunds for Submission Deposits on closed referenda that updated the ReferendumInfo type. The following invariants of ReferendumInfo were changed so that the second parameter, Deposit<AccountId, Balance>, is now optional, Option<Deposit<AccountId, Balance>>: Approved, Rejected, Cancelled, and TimedOut.

This stemmed from an upstream change to the Substrate repository.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

XCM-Related Pallets¶

Update Transact Info Storage Item¶

There was a migration applied to the TransactInfo storage item of the XCM Transactor Pallet that changed the following items:

• max_weight is added to prevent transactors from stalling the queue in the destination chain
• Removes fee_per_byte, metadata_size, and base_weight as these items are not necessary for XCM transactions
• fee_per_second replaces fee_per_weight to better reflect cases (like Kusama) in which the fee_per_weight unit is lower than one

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Add Support for Kusama Asset Hub (Statemine) Prefix Breaking Change¶

The following three migrations were added to the asset manager pallet to avoid issues with Kusama Asset Hub's (previously referred to as Statemine) breaking change to the way it represents assets and possible future breaking changes:

• UnitsWithAssetType - updates the AssetTypeUnitsPerSecond storage item to a mapping of the AssetType to units_per_second, instead of the mapping AssetId to units_per_second. This is done to avoid additional migrations whenever a breaking change arises
• PopulateAssetTypeIdStorage - creates a new AssetTypeId storage item that holds the AssetType to AssetId mapping, which allows the decoupling of assetIds and AssetTypes
• ChangeStateminePrefixes - updates already registered Kusama Asset Hub (Statemine) assets to their new form

These migrations were executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Add New Supported Fee Payment Assets Storage Item¶

A migration was applied to the asset manager pallet, creating a new SupportedFeePaymentAssets storage item by reading the supported asset data from the AssetTypeUnitsPerSecond storage item. This storage item will hold all the assets we accept for XCM fee payment. It will be read when an incoming XCM message is received, and if the asset is not in storage, the message will not be processed.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Update the XCM Transactor Storage from V2 to V3¶

With the support of XCM V3, a migration was applied to update the XCM Transactor pallet's storage from XCM V2 to V3. The transactInfoWithWeightLimit and destinationAssetFeePerSecond storage items were updated to support XCM V3 multilocations.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Remove Mintable XC-20s¶

Mintable XC-20s were deprecated in favor of XCM-enabled ERC-20s; as such, a migration was applied to remove the local assets pallet and clear the assets in storage.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative PR on GitHub.

Nimbus Author Filter Pallet¶

Replace Eligible Ratio with Eligible Count¶

A breaking change was applied to the Nimbus repository, deprecating EligibleRatio in favor of the EligibleCount config. As a result, a migration was applied to the Moonbeam repository, populating the new EligibleCount value as a percentage of the potential authors defined at that block height if the EligibleRatio value existed. Otherwise, the value was set to a default value of 50.

This migration was executed at the following runtimes and blocks:

For more information, you can review the relative Nimbus PR and Moonbeam PR on GitHub.