staking-expiry-checker

Description

The staking-expiry-checker program is a core service that manages the transitions for Phase 1 delegations that have not transitioned to Phase 2. It does this by monitoring the expiration of the timelocks as well as unbonding and withrawing Bitcoin transactions.

This program is responsible for:

• timelock expiry monitoring — ensuring delegations that expired are set to unbonded

• unbonding transaction detection — updating delegations based on unbonding transactions

• withdrawal transaction tracking — detecting when withdrawal transactions occur

• storing and updating delegation statues in the shared MongoDB database

Here are its key functionalities:

• BTC Subscriber Poller — subscribes to Bitcoin spend notifications for staking/unbonding transaction spends to update the database

• Expiry Checker Poller — regularly polls the timelock queue table to identify delegation timelock expiry

Invariants

• State updates should be well-defined and consistent, so delegations can only transition through states in the correct sequences

• Delegation statues should be reliable and accurate, reflecting the true state of the blockchain at the current time

Test coverage

Cases not covered

• Tests to verify general functionality of the program

• Correct processing of delayed or malformed Bitcoin notification data

• Graceful error handling and recovery

Attack surface

The attack surface for the program is malicious or malformed Bitcoin transaction data that may cause the program to fail. For example, this could come from a malicious transaction sent by an attacker, or by a compromised Bitcoin node.