Fix False Positive Alerts in Incorrect Bond Balance Monitor

[narendravarma7]

Context & Root Cause

The existing Gatelang monitor for Dispute Game Incorrect Bond Balance was producing false positive alerts due to a race condition between the real-time Events data source and HistoricalEvents. This issue occurs when:

1. The HistoricalEvents source retrieves past withdrawal events, but its indexing does not always include transactions from the most recent block.
2. The current block's withdrawals are not accounted for in HistoricalEvents, causing a temporary imbalance in calculations.
3. This results in the monitor detecting an ETH discrepancy and incorrectly triggering an alert.

Recommended Fix by Hexagate

Hexagate suggested excluding the current block's withdrawals from HistoricalEvents and tracking real-time withdrawals separately using the Events source. This prevents race conditions and ensures accurate ETH balance monitoring.

Implemented Fix

modified the monitor script with the following changes:

1. Separate Tracking for Current and Historical Withdrawals

• Added currentWithdrawal source using Events to track real-time ETH withdrawals from the Dispute Game contract.
• Updated pastWithdrawalEvents to exclude current block withdrawals by filtering based on BlockNumber {}.
• Introduced currentWithdrawals to extract amounts from currentWithdrawal events and sum them correctly.

2. Ensured Correct Balance Calculation

• The total ETH balance now includes both past and current withdrawals.
• The final invariant condition verifies that the total balance is correct by ensuring:

  totalDisputeEthBalance - (futureEthUnlocked + Sum { sequence: unlockAmounts }) == 0
  

Testing & Validation

• The updated monitor was tested against Ethereum Sepolia block 7606607(https://sepolia.etherscan.io/tx/0xbb0aea9c9863f603de9f3b0b44241eb0ce2e2d98f6e636b595858a36fb2a0626) , and no false positives were observed.
• Output data confirmed that real-time withdrawals were correctly included while ensuring historical withdrawals were properly accounted for.

Next Steps

• Deploy the updated monitor using Tines Automation and observe performance over multiple blocks.

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 1/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[awilliams1-cb]

• Left a couple nits, overall the logic looks good
• Looks like the current tests still work, but parsing the past and current withdrawals separately and adding them together is new logic that should have its own test
• I checked the other two gate files that make use of HistoricalEvents and their invocations of it shouldn't encounter this issue

[cb-heimdall]

Review Error for awilliams1-cb @ 2025-01-31 19:39:16 UTC
User failed mfa authentication, public email is not set on your github profile. see go/mfa-help

[cb-heimdall]

Review Error for awilliams1-cb @ 2025-02-01 19:16:15 UTC
User cannot review their own commit

[tomryan-cb]

lgtm!