Data logging
From Freepedia
Data logging is the practice of recording, in some medium, sequential data, often in a time-associated format.
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Origin of the term
The earliest kind of data logging was associated with keeping the ship's log in old sailing vessels.
The captain would typically make at least a daily entry recording the date, time, weather, sea conditions, bearing, estimated speed, and any noteworthy events. The ship's speed was historically measured by throwing a wooden log attached to a rope overboard and counting the number of knots in a rope that passed through a sailor's fingers within a certain time. (For this reason, the speed of ships is still measured in knots.)
Now any time-sequential record of events or conditions is called a log.
Modern data logging
In modern data logging, the status of systems is automatically recorded to provide an audit trail that can be used to diagnose problems after the fact.
Examples of physical systems which have logging subsystems include process control systems, and the black box recorders installed in aircraft.
Many software packages have logging subsystems built-in. Many operating systems provide a syslog service (as specified in RFC 3164), which allows the filtering and recording of log messages to be performed by a separate dedicated subsystem, rather than having a different logging system for every software package. Other software servers splunk the log files, assisting, or automating, the diagnosis of problems recorded in log files, including the discovery of connections between seemingly unrelated events on different servers.
