LND sets 10,000 sat/vB ceiling for external Bitcoin fee estimates

2 min

LND’s v0.21.5-beta.rc1 focuses on bounding external fee inputs and improving node reliability: a ceiling on outside fee estimates reduces wallet exposure to upstream errors, and a SQL connection-pool deadlock fix targets operational stability.

TL;DR

Build: v0.21.5-beta.rc1 pre-release with no database migration.
Fees: caps external fee API at 10,000 sat/vB and bounds minimum-relay estimate.
Ops: adds native SQL pool deadlock fix; verification proves download integrity, not runtime behavior.

External fee estimates now have a ceiling

The release notes state that previous logic enforced a lower bound without an upper bound on external fee estimates. The fix limits the value before it feeds wallet decisions. The change applies a 10,000 satoshi per vbyte ceiling and bounds the minimum-relay estimate from the API. The cap functions as an extreme-value guardrail, not as guidance on typical or required fees. Fee estimates inform decisions. Bounding inputs reduces the impact of errors, format changes, or compromised dependencies. This aligns with the need for both issue discovery and safe deployment paths highlighted by Bitcoin Core’s revised disclosure process.

Pre-release status, verification, and real-world testing

The pre-release includes signature and binary verification instructions. These confirm download integrity, not behavior across all node configurations. The notes also include a native SQL connection-pool deadlock fix. Reliability depends on storage as well as networking, since a running process that stops completing requests still fails dependent applications. Candidate testing needs to cover production workflows: receiving and serving requests, accessing storage, handling failures, and restarting cleanly. The absence of a migration removes one change category but does not guarantee unchanged interactions with existing data. Custody controls such as shared-key Bitcoin lending and insurance-backed custody address signing authority and recovery. They do not replace software maintenance or operational testing. Final release and deployment decisions remain separate steps.