November 2008 - logback-user

Feedback from using Logback in an audit component
by Anders Hammar 04 Nov '08

04 Nov '08

I was asked by Ceki to share my successful Logback story with you all. In a former assignment for one of our customers, we implemented an audit component. The customer is to use this component in their applications to audit end-user activities. In some earlier application specific audit implementations, log4j had been used. However, log4j (and pretty much all existing application logging frameworks that I looked at) has the notion of logging levels. For auditing (at least in this customer's case) we have actions/events which have no relation between them. So, having levels of debug, info, warn, etc isn't right but we rather have independent events. When I found Logback it was kind of love at first sight, the modular design fitted beautifully with what we wanted and we chose Logback (specifically logback-core) for our actual audit logging. We based this choice on two factors in specific: 1. The possibility of log on actions/events rather than levels (as above described) 2. The possiblity of having several independently configured logback instances. (This is not possible with log4j for instance, and as the customer's app server of choice uses log4j we would need to combine application logging and audit logging configuration - which is not good out of security perspective.) Also, the extensive documentation made my work easy to recommend the framework. As we all know, good documentation is not always the case in OSS. However, as mentioned on the mailing list earlier, the lack of a 1.0 release could have been a problem. However, Ceki's track record (with log4j) made me feel safe still going with Logback. As i personally strongly believe in OSS I normally participate and contribute to the community of the libs I use. However, working as a consultant I just can't be involved in everything and tend to only stay active as long as the assignment lasts (there are a few exceptions). Therefore I don't subscribe to this mailing list any longer, but I will monitor this thread so if you have any questions regarding my use case I'll be happy to answer them. /Anders

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SocketAppender
by Greg Flex 03 Nov '08

03 Nov '08

Hi all, So I still have some problems with the socketAppender. I'm using the server and the client (sample code) that comes with the Logback. I'm sending a string to a server that is about 4KB in size. (in the "for" loop) When I'm executing this "for" loop once or twice or even 4 times nothing gets transmitted from the client to the server. I get nothing just a message that server is waiting for data, then I get message saying that the socket connections has been closed. Now, when I'm executing the same exactly code and I'm running the same loop (that sends the 4KB string over to the server) but say 10 or more times, everything works! I'm not an expert on how TCP/IP works but it looks to me that the socket closes the connection before the data I'm sending gets actually transmitted to the server. How do I keep the socket open until the data gets to the server? Any suggestion? Thanks Greg

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Problem with Context Selector: No appenders present in context?
by Joop Vriend 01 Nov '08

01 Nov '08

Hi, I'm having problems using (or configuring?) the logback Context Selector. I followed all the instructions of the manual: http://logback.qos.ch/manual/contextSelector.html But I get the error-message: 20:10:26,365 |-ERROR in Logger[com.ddnh.product.ncmdb] - No appenders present in context [ContextApp-NCMDB] for logger [com.ddnh.product.ncmdb]. And when undeploying also: About to detach context named ContextApp-NCMDB No context named ContextApp-NCMDB was found. I'm using Tomcat 6.0 (with -Dlogback.ContextSelector=JNDI). I placed all the slf4j and logback jars in the TOMCAT_HOME/lib directory: slf4j-api-1.5.5.jar logback-core-0.9.11.jar logback-classic-0.9.11.jar logback-access-0.9.11.jar jul-to-slf4j-1.5.5.jar jcl-over-slf4j-1.5.5.jar janino.jar I edited my web.xml of my webapp "NCMDB": <env-entry> <description>JNDI logging context for this app</description> <env-entry-name>logback/context-name</env-entry-name> <env-entry-type>java.lang.String</env-entry-type> <env-entry-value>ContextApp-NCMDB</env-entry-value> </env-entry> <env-entry> <description>URL for configuring logback context</description> <env-entry-name>logback/configuration-resource</env-entry-name> <env-entry-type>java.lang.String</env-entry-type> <env-entry-value>logback.xml</env-entry-value> </env-entry> <listener> <listener-class>ch.qos.logback.classic.selector.servlet.ContextDetachingSCL</listener-class> </listener> <filter> <filter-name>LoggerContextFilter</filter-name> <filter-class>ch.qos.logback.classic.selector.servlet.LoggerContextFilter</filter-class> </filter> <filter-mapping> <filter-name>LoggerContextFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> And the logback.xml (in WEB-INF/classes) is as follows: <configuration> <evaluator name="WARN_EVALUATOR"> <expression>level == WARN</expression> </evaluator> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> <layout class="ch.qos.logback.classic.PatternLayout"> <pattern>%date{yyyy-MM-dd HH:mm:ss} %class %method $%file:%line$%n %level: %message%n%caller{5,WARN_EVALUATOR}%exception{15}</pattern> </layout> </appender> <appender name="RootFileAppender" class="ch.qos.logback.core.rolling.RollingFileAppender"> <append>true</append> <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"> <fileNamePattern>${catalina.base}/logs/ncmdb.ddnh.%d{yyyy-MM-dd}.log.gz</fileNamePattern> </rollingPolicy> <layout class="ch.qos.logback.classic.PatternLayout"> <pattern>%date{yyyy-MM-dd HH:mm:ss} %class %method $%file:%line$%n %level: %message%n%caller{5,WARN_EVALUATOR}%exception{15}</pattern> </layout> <filter class="ch.qos.logback.classic.filter.ThresholdFilter"> <level>DEBUG</level> </filter> </appender> <logger name="com.ddnh.product.ncmdb" additivity="false"> <level value="DEBUG"/> <appender-ref ref="RootFileAppender"/> <appender-ref ref="RootEmailAppender"/> </logger> <root> <level value="DEBUG"/> <appender-ref ref="STDOUT" /> <appender-ref ref="RootFileAppender"/> <appender-ref ref="RootEmailAppender"/> </root> </configuration> What am I doing wrong?? Any help is appreciated. Thanks, Joop.

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