@Plugin(name="DefaultRolloverStrategy", category="Core", printObject=true) public class DefaultRolloverStrategy extends Object implements RolloverStrategy
DefaultRolloverStrategy
renames files
according to an algorithm as described below.
The DefaultRolloverStrategy is a combination of a time-based policy and a fixed-window policy. When the file name pattern contains a date format then the rollover time interval will be used to calculate the time to use in the file pattern. When the file pattern contains an integer replacement token one of the counting techniques will be used.
When the ascending attribute is set to true (the default) then the counter will be incremented and the current log file will be renamed to include the counter value. If the counter hits the maximum value then the oldest file, which will have the smallest counter, will be deleted, all other files will be renamed to have their counter decremented and then the current file will be renamed to have the maximum counter value. Note that with this counting strategy specifying a large maximum value may entirely avoid renaming files.
When the ascending attribute is false, then the "normal" fixed-window strategy will be used.
Let max and min represent the values of respectively
the MaxIndex and MinIndex options. Let "foo.log" be the value
of the ActiveFile option and "foo.%i.log" the value of
FileNamePattern. Then, when rolling over, the file
foo.max.log
will be deleted, the file
foo.max-1.log
will be renamed as
foo.max.log
, the file foo.max-2.log
renamed as foo.max-1.log
, and so on,
the file foo.min+1.log
renamed as
foo.min+2.log
. Lastly, the active file foo.log
will be renamed as foo.min.log
and a new active file name
foo.log
will be created.
Given that this rollover algorithm requires as many file renaming operations as the window size, large window sizes are discouraged.
Modifier and Type | Field and Description |
---|---|
protected static org.apache.logging.log4j.Logger |
LOGGER
Allow subclasses access to the status logger without creating another instance.
|
Modifier | Constructor and Description |
---|---|
protected |
DefaultRolloverStrategy(int minIndex,
int maxIndex,
boolean useMax,
int compressionLevel,
StrSubstitutor subst)
Constructs a new instance.
|
Modifier and Type | Method and Description |
---|---|
static DefaultRolloverStrategy |
createStrategy(String max,
String min,
String fileIndex,
String compressionLevelStr,
Configuration config)
Create the DefaultRolloverStrategy.
|
int |
getCompressionLevel() |
int |
getMaxIndex() |
int |
getMinIndex() |
RolloverDescription |
rollover(RollingFileManager manager)
Perform the rollover.
|
String |
toString() |
protected static final org.apache.logging.log4j.Logger LOGGER
protected DefaultRolloverStrategy(int minIndex, int maxIndex, boolean useMax, int compressionLevel, StrSubstitutor subst)
minIndex
- The minimum index.maxIndex
- The maximum index.@PluginFactory public static DefaultRolloverStrategy createStrategy(@PluginAttribute(value="max") String max, @PluginAttribute(value="min") String min, @PluginAttribute(value="fileIndex") String fileIndex, @PluginAttribute(value="compressionLevel") String compressionLevelStr, @PluginConfiguration Configuration config)
max
- The maximum number of files to keep.min
- The minimum number of files to keep.fileIndex
- If set to "max" (the default), files with a higher index will be newer than files with a
smaller index. If set to "min", file renaming and the counter will follow the Fixed Window strategy.compressionLevelStr
- The compression level, 0 (less) through 9 (more); applies only to ZIP files.config
- The Configuration.public int getCompressionLevel()
public int getMaxIndex()
public int getMinIndex()
public RolloverDescription rollover(RollingFileManager manager) throws SecurityException
rollover
in interface RolloverStrategy
manager
- The RollingFileManager name for current active log file.SecurityException
- if an error occurs.Copyright © 1999-2021 Apache Software Foundation. All Rights Reserved.
Apache Logging, Apache Log4j, Log4j, Apache, the Apache feather logo, the Apache Logging project logo, and the Apache Log4j logo are trademarks of The Apache Software Foundation.