Switch to UTC time for Redis data store #473
Description
Stoplight currently uses local time for Redis key generation and time bucketing. This causes issues during daylight saving time transitions:
- When clocks fall back 1 hour, Stoplight reads statistics from the previous hour, causing incorrect error rate calculations and potentially inappropriate circuit breaker state changes
- When clocks spring forward 1 houh, there's a gap in statistics, which may cause circuits to incorrectly open due to missing data
- Services deployed in different timezones may have inconsistent behavior
Proposed Solution
Use UTC time consistently for all Redis operations:
- Time bucket key generation
- Timestamp storage in ZSETs
- TTL calculations
- All time-based logic
Impact on Users
- Metric continuity will be broken during upgrade from v5.x to v6.0.0
- During the upgrade window (roughly the duration of the configured
window_size), circuits may have incomplete data - This is a one-time issue; after the upgrade window passes, behavior will be normal