How to enable logging of Ehcache - spring

Question

In my Spring + Hibernate project, I was doing logging by SLF4J 1.6.4 with LogBack. Now, I've added Ehcache 2.2.0 (through ehcache-spring-annotations-1.1.3). The caching seems to be working as the method, annotated with #Cacheable, no longer being executed, though returning the correct result. But, I'm interested to see the log written by the Ehcache. As Ehcache also uses SLF4J, I supposed, the log should be written into my log file. But, this is not happening. The logback.xml has the following.
<root level="info">
<appender-ref ref="STDOUT"/>
<appender-ref ref="ROLLING"/>
</root>
Adding following also doesn't help
<logger name="net.sf.ehcache">
</logger>
Ehcache.xml
<cache name="sampleCache1"
eternal="false"
overflowToDisk="true"
timeToIdleSeconds="300"
timeToLiveSeconds="600"
memoryStoreEvictionPolicy="LFU"
/>
Please advise me to overcome the problem.
The Ehcache is using SLF4J 1.6.1, while my project was using SLF4J 1.6.4. Can it cause any problem?
Thanks

Answer 1

EhCache logs a lot on DEBUG level. First of all, this configuration snippet filters out all logging statements below INFO:
<root level="info">
Change it to
<root level="ALL">
Secondly
<logger name="net.sf.ehcache">
needs an increased logging level
<logger name="net.sf.ehcache" level="ALL"/>
You should then see plenty of logging statements from EhCache (and others).

Answer 2

In my opinion setting the root logger level to ALL is not a good idea.
This means that ALL log messages of every level will get through (unless you set a threshold on your appenders).
Instead, I suggest you set a sensible root logger level, such as INFO or WARN, and then set the log level of individual loggers if you require more specific information.
This way you are not creating a forest of unnecessary information.
I suggest something like the below:
<appender name="CONSOLE" class="org.apache.log4j.ConsoleAppender">
<param name="Target" value="System.out"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p [%c] %m%n"/>
</layout>
</appender>
<logger name="net.sf.ehcache">
<level value="DEBUG"/>
</logger>
<root>
<priority value ="INFO" />
<appender-ref ref="CONSOLE" />
</root>

Answer 3

I also found it handy to enable DEBUG logging on org.springframework.cache because I'm using Spring Framework 4.2.1's caching feature (#Cacheable etc.).

Answer 4

I wrote a custom logger for Ehcache 3 by implementing the CacheEventListener interface as follows
public class CacheLogger implements CacheEventListener<Object, Object> {
private static final Logger LOG = LoggerFactory.getLogger(CacheLogger.class);
#Override
public void onEvent(CacheEvent<?, ?> cacheEvent) {
LOG.info("YOUR LOG IS HERE");
}
}
The ehcache.xml will define the listener class
<cache-template name="default">
<expiry>
<ttl unit="seconds">300</ttl>
</expiry>
<listeners>
<listener>
<class>com.path.to.CacheLogger</class>
<event-firing-mode>ASYNCHRONOUS</event-firing-mode>
<event-ordering-mode>UNORDERED</event-ordering-mode>
<events-to-fire-on>CREATED</events-to-fire-on>
<events-to-fire-on>EXPIRED</events-to-fire-on>
<events-to-fire-on>EVICTED</events-to-fire-on>
</listener>
</listeners>
<resources>
<heap>1000</heap>
<offheap unit="MB">10</offheap>
</resources>
</cache-template>