Hi： same as the title; recently,Our system has been transformed into a distributed system with all log append to same file; （ELK need more machine,can not take it） but only one service can log success ,(others all failed,but can lot catalina.out) <configuration debug="true">, but Unable to track problem with logback self logs（has no log about filelock）; reviewed Code `FileAppender.safeWrite()` ,it has file lock ; here is some linxu echos , may help; thanks a lot!