MQ_LOG_FILE specifies the file to which log messages are directed. If you do not specify a file name for this variable, stderr is used. If MQ_LOG_FILE is a directory name, it should include a trailing directory separator.
By default, .n (where n is 0, 1, 2,...) is appended to the actual log file name. This is used as a rotation index, and the indices are used sequentially when the maximum log file size is reached. You can use %g to specify a rotation index replacement in MQ_LOG_FILE after the last directory separator. Only the last %g is used if multiple %g’s are specified. the %g replacement can be escaped with %. The maximum rotation index is 9, and the maximum log file size is 1 MB. These limits are not configurable.