Time based triggering policy in log4j2

Question

I am trying to create new log files on an hourly basis. I am using TimeBasedTriggerringPolicy of lo4j2 in RollingFileAppender. Below is the sample xml configuration code i have taken from log4j2 official site.

<?xml version="1.0" encoding="UTF-8"?> <Configuration status="warn" name="MyApp" packages="">    <Appenders>       <RollingFile name="RollingFile" fileName="logs/app.log" filePattern="logs/$${date:yyyy-MM}/app-%d{yyyy-MM-dd-HH}-%i.log.gz">          <PatternLayout>             <Pattern>%d %p %c{1.} [%t] %m%n</Pattern>          </PatternLayout>          <Policies>             **             <TimeBasedTriggeringPolicy interval="1" modulate="true" />             **             <SizeBasedTriggeringPolicy size="250 MB" />          </Policies>       </RollingFile>    </Appenders>    <Loggers>       <Root level="error">          <AppenderRef ref="RollingFile" />       </Root>    </Loggers> </Configuration> 

In the interval attribute I have set 1 which signifies 1 hour. But still my file does not roll every 1 hour.

Please help me find any mistake.

Note : I have included beta9 of log4j2 (which is the latest)

Answer 1

1 here indicates 1 day and not 1 hour. I have manually tested with below configuration.

<RollingFile name="T" fileName="/data_test/log/abc.log"         filePattern="/data_test/log/abc-%d{MM-dd-yyyy}-%i.log">         <PatternLayout>             <Pattern>%d{ISO8601} %-5p [%t] (%F:%L) - %m%n</Pattern>         </PatternLayout>         <Policies>                           <TimeBasedTriggeringPolicy interval="1" modulate="true"/>             <SizeBasedTriggeringPolicy size="100 KB" />         </Policies>     </RollingFile> 

For manual testing, I change the system date and time. First, try with increasing 1 hour. The log files will be generated but not as per the expectation. Then change the system date, increase by 1 day and then see the results.

Suppose the last log file (abc.log) on day 29-Oct is of 50 KB. Configuration size is 100 KB. If we change the day (increase by 1 day) and then run. Then, last file will be renamed 29-Oct-(some sequence number).log (50 KB file as it is copied) and new file will be created with abc.log

I have tried this with simple servlet with below configuration in web.xml

<context-param>     <param-name>log4jConfiguration</param-name>     <param-value>log4j2.xml</param-value> </context-param> 

keep log4j2.xml in src folder. log4j2.xml is not loaded if we keep it in classpath.

Answer 2

Log4j documentations:

interval -> (integer) How often a rollover should occur based on the most specific time unit in the date pattern. For example, with a date pattern with hours as the most specific item and and increment of 4 rollovers would occur every 4 hours. The default value is 1.

You should change the filename pattern if you would like to create it every hour.