Create index on transactions.blockNumber for lite nodes

[TheCrazyGM]

Problem

During lite node operations, the LightNode plugin periodically purges historical data. The transaction cleanup logic in libs/Database.js executes the following query every 10 minutes:

await this.database.collection('transactions').deleteMany({ blockNumber: { $lte: cleanupUntilBlock } });

Because the transactions collection lacked an index on blockNumber, MongoDB was forced to perform a full collection scan (COLLSCAN) through approximately 40 million records (~3.19 GB) per cycle. This created severe, compounding overhead on system memory, CPU utilization, and disk I/O.

Solution

• Manual Mitigation: Successfully verified the fix by manually building the index on the target database:

  db.transactions.createIndex({ blockNumber: 1 })

• Programmatic Fix: Updated libs/Database.js to ensure this index is automatically created on startup, preventing regressions on fresh node deployments.

Impact

• Eliminates the 10-minute COLLSCAN spikes.
• Drastically reduces ambient CPU usage and disk I/O bottlenecks for all node operators running a lite strategy.