java - Log4j dailyrollingfileappender file issues

Question

We are encountering a peculiar problem. Scenario: We have 3 servers which with multiple instances of a component all writing transactional log to a single log file.We use log4j and the servers run in Java 1.3. setAppend() is passed true and implementation is DailyRollingFileAppender

Problem: At midnight, we are expecting the current log file to roll over with a new file name and start writing to a new file. This is working well in our test setup (single server writing logs). In production, at midnight, new file is getting created where new logs are getting written but rolled over file is getting deleted

Any help will be highly appreciated as its been couple of days and we are not able to get any leads for the problem.

Answer 1

You should not log to the same file from many processes. Log4j is thread-safe all right, but it's not process-safe, if I may say so; it does not work as a shared library among different java processes. Log4j embedded in one java application has no knowledge of any other one.

With rollover it causes the problem you've just discovered: all processes run their own rollover code, blindly overwriting the previous contents (because none of them expects any).

A possible solution here: Log4j Logging to a Shared Log File