How to use logging to spot bugs
Let’s start with a trivial but useful method for understanding what a software program does while executing – logging.
Logging is the process of keeping a log of events that occur in a program, storing information by using messages to record how a program executes, tracking its flow, and helping with identifying issues and bugs.
Most Unix-based logging systems use the standard protocol, syslog, created by Eric Altman back in 1980 as part of the Sendmail project. This standard protocol defines the boundaries between the software generating the log messages, the system storing them, and the software reporting and analyzing these log events.
Each log message includes a facility code and a severity level. The facility code identifies the type of system that originated a specific log message (user-level, kernel, system, network, etc.), and the severity level describes the condition of the system, indicating the urgency of dealing with...
