Apama 10.15.0 | Developing Apama Applications | Developing Apama Applications in EPL | Defining What Happens When Matching Events Are Found | Logging and printing | Specifying log statements
 
Specifying log statements
The format of a log statement is as follows:
log string [at identifier]
Syntax description
Syntax Element
Description
string
Specify an expression that evaluates to a string.
identifier
Optionally, specify the desired log level. Specify one of the following values: CRIT, FATAL, ERROR, WARN, INFO, DEBUG or TRACE. If you do not specify an identifier, the default is INFO.
It is recommended that you do not use the FATAL or CRIT log levels, which are present only for historical reasons. It is better to use ERROR for all error conditions regardless of how fatal they are, and INFO for informational messages.
For each encountered log statement, the correlator compares the specified identifier with the applicable log level to determine whether to send the specified string to a log file. If the string is to be sent to a log file, the correlator determines the appropriate log file to send it to.
The correlator uses the tree structure of EPL code to identify the applicable log level and the appropriate log file. See Setting EPL log files and log levels dynamically.