TheFATALlogging level is the special severity level that thedw.system.LogAPI identifies as always enabled under normal logging operation. It represents severe conditions for which developers should always be able to emit diagnostic information.
Salesforce ' sdw.system.LogAPI documentation explicitly states thatFatal log messages are always enabledand can optionally be distributed through email notification configuration. INFO, by contrast, depends on the configured logging threshold and target settings. ERROR also participates in the configurable category hierarchy and does not carry the same API-level guarantee expressed for FATAL.
B2C Commerce custom logging uses a log4j-style hierarchy. Categories inherit logging behavior from parent categories unless a more specific rule applies. For example, an INFO threshold permits INFO, WARN, ERROR, and FATAL. A WARN threshold permits WARN, ERROR, and FATAL. Salesforce also supports configuring log targets separately from filters.
FATAL should be reserved for genuinely severe application conditions rather than routine diagnostic output, because excessive high-severity logging obscures operational incidents and reduces the diagnostic value of the logs.
Study Guide reference:Application Development -dw.system.Log, logging severity, custom log categories, FATAL logging, and production diagnostics.