We have a system which generates high volume logs which are required to be preserved for audit purposes, and have been having problems with files being unexpectedly overwritten.
We are using a RollingFile appender with day granularity, time based and size based triggering policies, and a rollover strategy with a suitably large max value.
I have created a simple test case with minute granularity to quickly illustrate the problem, which is v. similar to the example given in the documentation:
... with a config of:
If this is run as is many of the rollover logfiles have other files written over them and are lost, as can clearly be seen by the gaps in the remaining sequence numbers, and the order the sequence numbers appear in the resulting files.
If the time based policy is removed from the config and it is re-run then all sequence numbers are correctly stored and in the expected order., Without the time based trigger some are carried over into the folder for the next period which is not ideal, though is what we are using at present to avoid data loss.