Bitcoin: Does `autoclean-once` without vacuuming lightningd.sqlite3 slow down the future growth of size lightningd.sqlite3?

Impact of Autocleaning on Lightningd SQLite3: Slowing Down Growth

Lightning CLI has changed the game for the Bitcoin network by allowing users to create and manage Lightning Network nodes. One of the key features that enables this functionality is the autoclean-once mechanism, which periodically cleans up stale data to maintain node performance and security. However, some users have reported unusual behavior when using the autoclean-once command.

The Problem: Autocleaning Without Vacuuming

When you run lightning-cli autoclean-once, there are two different results depending on whether vacuum is used or not:

• Vacuumed Out: If the autoclean-once command uses the --vacuum flag, it will attempt to clean up stale data in the SQLite database. In this case, if lightningd.sqlite3 has been upgraded and new data has been added, this can cause significant slowdowns.

• Non-Vacuumed Out: If no vacuum is used (autoclean-once --), the autoclean-once command will only clean up stale data that has not changed since the last upgrade. In this scenario, lightningd.sqlite3 should continue to grow and update at its usual pace.

The Problem: Growth Slowdown

The problem arises because of the way autoclean-once handles upgrades and new data added to the SQLite database. Although it is intended to clean up stale data, some users have reported that automatic cleaning without vacuuming can slow down the growth of lightningd.sqlite3. This slowdown is likely due to the increased time it takes to upgrade and update the database.

Conclusion

The autoclean-once mechanism plays a crucial role in maintaining the performance and security of nodes on the Lightning Network. However, using it without vacuum can cause significant slowdowns in growth, especially during times of high activity or when new data is being added to the SQLite database. To avoid this issue, users should select the --vacuum flag when running autoclean-once.

Recommendation

To minimize the impact of autocleaning on lightningd.sqlite3 growth, use the --vacuum flag whenever possible:

• Use the following command: lightning-cli autoclean-once --vacuum

• Avoid using the default behavior (autoclean-once without vacuum);

• Regularly check for SQLite database updates and consider upgrading when necessary

By taking this precaution, users can ensure optimal performance and growth for their Lightning Network nodes.