Logging different type of events is a common practice for applications. While one application might categorize these types of events into errors, informational events, and warnings, others might throw in more elaborate levels of severity logging. The same goes for the actual format of the log message itself. Goes to say that every application might easily have its own flavor of logging mechanism. This stands in a way of interoperability.
The PSR-3 standard sets out to fix this by defining a standard for the actual logger interface. Such a standardized interface then enables us to write PHP application logs in a simple and universal way.
The syslog protocol (RFC 5424), defined by Internet Engineering Task Force (IETF), differentiates the following eight severity levels:
- emergency: This states the system is unusable
- alert: This states action must be taken...
