July 2009 - logback-dev - mailman3.qos.ch

[JIRA] Created: (LBCLASSIC-82) Allow an Appender to be added to a Logger with a Level for more fine grained control of logging output
by Robert Elliot (JIRA) 20 May '11

20 May '11

Allow an Appender to be added to a Logger with a Level for more fine grained control of logging output ------------------------------------------------------------------------------------------------------ Key: LBCLASSIC-82 URL: http://jira.qos.ch/browse/LBCLASSIC-82 Project: logback-classic Issue Type: New Feature Components: appender, joran Environment: N/A Reporter: Robert Elliot Assignee: Logback dev list Priority: Minor Here's my use case: I have an appender, standard.log, whose job is to log major system events such as startup and shutdown, and all problems. I have configured my logger levels very carefully to ensure I get exactly the output I want - in some cases suppressing WARN messages that I know are not a problem by setting the level to ERROR, in some cases allowing INFO messages that let me see important lifecycle events. A simplified example might look like this: root=WARN,standard.log x.y=INFO a=ERROR I have a problem in a couple of parts of the system which means I want to turn on debug logging for that part of the system. I want the output of this to go to a separate appender - debug.log. So now my config looks like this: root=WARN,standard.log x.y=INFO x.y.z=DEBUG,debug.log a=ERROR a.b=DEBUG,debug.log But now I have an issue; all my debug statements are going to standard.log. It is being polluted with a load of information I don't want in it. I have several options: 1) Set additivity to false on x.y.z and a.b. But then any ERROR messages in a.b or INFO or above messages in x.y.z no longer get to standard.log, so this won't do 2) Add a filter of INFO or greater to the standard.log appender But then any INFO and WARN messages in a.b will get to standard.log - and I only want ERROR messages from a and its descendants in there 3) Add a filter of WARN or greater to the standard.log appender Now I still get the WARN messages from a.b that I don't want - and I've lost the INFO messages from x.y that I do want 4) Create two new appenders, standard.log2 for a and standard.log3 for x.y.z. Add a filter to standard.log2 so that it only accepts ERROR. Add a filter to standard.log3 so it only accepts INFO or above. Set additivity to false on a and x.y.z. That works. But it's a huge amount of added configuration, and that would rapidly multiply in a real world setting. 5) Create a custom filter for standard.log which would effectively mirror the logger config by querying the event for its logger and and level. That blows DRY out of the water, of course, and again is a large amount of work for a simple use case. My suggestion to make this easy is to allow Appenders to be added to a Logger with a Level. This solution would operate in parallel with the existing solution, and would not alter the existing behaviour one iota. This would allow me to add debug,log as an appender on a and x.y.z with a level of debug. All debug statements in a and x.y.z & their descendants would be appended to that appender. All statements would also be passed to the "normal" appender and logger hierarchy, so standard.log would still get the same output as before. I have written unit tests for this behaviour and attach a patch fulfilling them; I hope the unit tests flesh out any queries you may have around how this behaves in edge cases. The only change to the public API is a new method addAppender(Appender<LoggingEvent> newAppender, Level level) on Logger. The only change to the config format is allowing an optional level attribute on appender-ref. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCLASSIC-113) Nullpointer
by Mathias Bogaert (JIRA) 23 Dec '10

23 Dec '10

Nullpointer ----------- Key: LBCLASSIC-113 URL: http://jira.qos.ch/browse/LBCLASSIC-113 Project: logback-classic Issue Type: Bug Components: Other Reporter: Mathias Bogaert Assignee: Logback dev list Priority: Critical java.lang.NullPointerException at ch.qos.logback.classic.Logger.callTurboFilters(Logger.java:769) [logback-classic-0.9.15.jar:na] at ch.qos.logback.classic.Logger.isTraceEnabled(Logger.java:641) [logback-classic-0.9.15.jar:na] at ch.qos.logback.classic.Logger.isTraceEnabled(Logger.java:637) [logback-classic-0.9.15.jar:na] at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:198) [hibernate-core-3.3.0.SP1.jar:3.3.0.SP1] at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:126) [hibernate-core-3.3.0.SP1.jar:3.3.0.SP1] at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:905) [hibernate-core-3.3.0.SP1.jar:3.3.0.SP1] Hibernate calls if ( log.isTraceEnabled() ). -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCLASSIC-130) Multiple resource warning is not appropriate for logback-test.xml
by Jon Vincent (JIRA) 20 Oct '10

20 Oct '10

Multiple resource warning is not appropriate for logback-test.xml ----------------------------------------------------------------- Key: LBCLASSIC-130 URL: http://jira.qos.ch/browse/LBCLASSIC-130 Project: logback-classic Issue Type: Improvement Affects Versions: 0.9.14, 0.9.15, 0.9.16 Reporter: Jon Vincent Assignee: Logback dev list Priority: Minor When LBCLASSIC-85 was fixed, it also applied to logback-test.xml. Unfortunately, some IDEs (such as Eclipse) include the test classpath for all modules in a multi-module project -- which means that it's nearly impossible to avoid having multiple logback-test.xml files on the classpath if one project depends on another when running tests in Eclipse. Every test in the project will therefore emit this warning when run from the IDE. Is it possible to have the ContextInitializer only emit this warning for logback.xml, and not logback-test.xml? This would avoid a spurious/unactionable warning for developers using Eclipse. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBGENERAL-28) JMX configurator should be able to use MBeanServers with a domain name
by C Z (JIRA) 09 Apr '10

09 Apr '10

JMX configurator should be able to use MBeanServers with a domain name ---------------------------------------------------------------------- Key: LBGENERAL-28 URL: http://jira.qos.ch/browse/LBGENERAL-28 Project: logback-general Issue Type: New Feature Affects Versions: 0.9.16 Reporter: C Z Assignee: Logback dev list Currently, logback exposes an MBean to provide logging related controls via the inclusion of the following configuration: <jmxConfigurator /> However, this *always* uses the platform mbean server: MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); (can be found in class JMXConfiguratorAction, line# 54). I think it should be able to provide an option to use an MBeanServer with a specific domain, which is provided in the JMX spec. The code needs to use the following: List servers = MBeanServerFactory.findMBeanServer(agentId); and then use the first one, possibly giving a warning if there are multiple. This is crucial for our use-case, especially because we have separate MBeanServers in our web-app environment, and we need each application to use its own MBeanServer with a specific domain. So, all in all, can we add an attribute of some sort, so that we can do the following: <jmxConfigurator agentid="someMbeanServerId"/> and if this is set, the code uses: MBeanServer mbs = MBeanServerFactory.findMBeanServer(agentId).get(0); and otherwise, it does whatever it used to do. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCORE-95) BurstFilter
by Ceki Gulcu (JIRA) 25 Mar '10

25 Mar '10

BurstFilter ----------- Key: LBCORE-95 URL: http://jira.qos.ch/browse/LBCORE-95 Project: logback-core Issue Type: New Feature Reporter: Ceki Gulcu Assignee: Ceki Gulcu A filter to regulate log message bursts, useful for things like throttling the number of logs sent to an e-mail appender when the database is unavailable. See http://www.qos.ch/pipermail/logback-dev/2009-March/003921.html -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCORE-97) Starvation on AppenderBase.doAppend
by Joern Huxhorn (JIRA) 23 Mar '10

23 Mar '10

Starvation on AppenderBase.doAppend ----------------------------------- Key: LBCORE-97 URL: http://jira.qos.ch/browse/LBCORE-97 Project: logback-core Issue Type: Bug Components: Appender Affects Versions: 0.9.15 Reporter: Joern Huxhorn Assignee: Logback dev list Priority: Critical Attachments: AppenderBaseLock.patch The problem we are facing here is that several threads are trying to obtain the object monitor of the exact same resource, namely the Appender. The assumption that multiple threads waiting for ownership of a monitor would receive the monitor in the order that they tried to acquire it is simply incorrect. This is documented behavior. See the last paragraph of [1]: "Likewise, no assumptions should be made about the order in which threads are granted ownership of a monitor or the order in which threads wake in response to the notify or notifyAll method. An excellent reference for these topics is Chapter 9, "Threads," in Joshua Bloch's book Effective Java Programming Language Guide. " The documentation of Object.notifyAll() [2] states the following: "[..] The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object." The documentation in [5] also lists the following as a weak-spot of Built-in Synchronization in J2SE 1.4.x: "No way to alter the semantics of a lock, for example, with respect to reentrancy, read versus write protection, or fairness." In LBCORE-96 Ceki stated the following: "Logback is using the standard synchronization mechanism found in the JDK. You are saying that that mechanism is unsuitable which, truth be told, sounds quite suspicious." Yes, it's unsuitable in this situation because obtaining the object monitor is not guaranteed to be fair. It's not working in a "first come, first serve" manner. I assumed that, too, but it isn't the case. I had the exact same problem in Lilith some time ago because I made exactly this very same wrong assumption. Fairness of object monitor lock acquisition seems to be logical and a "good thing" but it's not specified that way, and for good reasons. Without fairness in place, the VM can optimize the execution of an application much better. A context switch is a costly operation for a CPU so performance is increased significantly if such a switch can be omitted. Concerning a test-case, this would be pretty hardcore to implement since it's 100% implementation dependent. One implementation *may* handle the locking of object monitors fairly while others don't. Therefore I'll try the following first: I assume I could convince you that object monitor acquisition (OMA) is not fair. If we take that for granted the following scenario should show my point: There are 4 Threads (e.g. 4 Threads handling concurrent webapp-requests) that have one single chokepoint, the appender. Since OMA isn't fair, it's possible that only some of those threads can work at all (see [3]). Exactly that is happening right now in our webapp running on a 4-core Solaris on JDK6. My next assumption is that we both agree that this isn't acceptable behavior. Logging should be handled "first come, first served" so that if Thread A is waiting to append an event and Thread B is waiting to append an event subsequently, the actual appending order should be A, then B. This is currently not the case. It *may* be the case but there is no guarantee of it. One could even argue that the logging system is working incorrectly (aside from the starvation problem) because events are appended in a different order than the actual execution of the logger call. The only way to prevent this is the introduction of fairness into the locking process. The way to do this is to use ReentrantLock [4]. >From the ReentrantLock javadoc: "The constructor for this class accepts an optional fairness parameter. When set true, under contention, locks favor granting access to the longest-waiting thread. Otherwise this lock does not guarantee any particular access order. Programs using fair locks accessed by many threads may display lower overall throughput (i.e., are slower; often much slower) than those using the default setting, but have smaller variances in times to obtain locks and guarantee lack of starvation." This is exactly what is absolutely necessary for a logging framework. Logging must *NOT* be able to introduce a starvation problem into a multi-threaded application! And it does exactly that right now. I doubt that the performance will decrease in a significant manner due to the use of a fair ReentrantLock but even if this would be the case it would be necessary anyway. Otherwise, appending simply isn't working correctly. [1] http://java.sun.com/j2se/1.5.0/docs/guide/vm/thread-priorities.html [2] http://java.sun.com/javase/6/docs/api/java/lang/Object.html#notifyAll() [3] http://en.wikipedia.org/wiki/Starvation_(computing) [4] http://java.sun.com/javase/6/docs/api/java/util/concurrent/locks/ReentrantL… [5] http://java.sun.com/developer/technicalArticles/J2SE/concurrency/ -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCORE-93) FlushingPolicy
by Ceki Gulcu (JIRA) 18 Mar '10

18 Mar '10

FlushingPolicy -------------- Key: LBCORE-93 URL: http://jira.qos.ch/browse/LBCORE-93 Project: logback-core Issue Type: New Feature Reporter: Ceki Gulcu Assignee: Logback dev list Let flushing be a settable policy of WriteAppender. Thus, the user would be able to set the FlushingPolicy of a WriterAppender or any derived class which would allow you to flush the underlying output stream according to any criteria available to the shouldFlush() method (see below), including time. Here is the relevant interface: interface FlushingPolicy { booelan shouldFlush(LoggingEvent e); } We could easily imagine a policy flushing on every warning or error in addition to special markers. For example, Marker FLUSH = MarkerFactory.getMarker("FLUSH"); logger.info(FLUSH, "finished serving request {}", request.getId()); -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCORE-109) FileAppender writing to a shared (networked) file system
by Ceki Gulcu (JIRA) 03 Mar '10

03 Mar '10

FileAppender writing to a shared (networked) file system -------------------------------------------------------- Key: LBCORE-109 URL: http://jira.qos.ch/browse/LBCORE-109 Project: logback-core Issue Type: Bug Affects Versions: 0.9.9, 0.9.10, 0.9.11, 0.9.12, 0.9.13, 0.9.14, 0.9.15 Reporter: Ceki Gulcu Assignee: Logback dev list FileAppender writing to a shared (networked) file system with lost networked connection. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCLASSIC-112) ch.qos.logback.classic.net.SMTPAppender_SubethaSMTPTest hangs on Mac OS X
by Joern Huxhorn (JIRA) 03 Mar '10

03 Mar '10

ch.qos.logback.classic.net.SMTPAppender_SubethaSMTPTest hangs on Mac OS X ------------------------------------------------------------------------- Key: LBCLASSIC-112 URL: http://jira.qos.ch/browse/LBCLASSIC-112 Project: logback-classic Issue Type: Bug Affects Versions: 0.9.16 Reporter: Joern Huxhorn Assignee: Logback dev list This test keeps hanging repeatedly at the very same spot. I'll attach a file with further info. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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[JIRA] Created: (LBCLASSIC-102) Suggestion: Change logger name of inner classes.
by Joern Huxhorn (JIRA) 15 Dec '09

15 Dec '09

Suggestion: Change logger name of inner classes. ------------------------------------------------ Key: LBCLASSIC-102 URL: http://jira.qos.ch/browse/LBCLASSIC-102 Project: logback-classic Issue Type: Improvement Components: appender Affects Versions: 0.9.15 Reporter: Joern Huxhorn Assignee: Logback dev list At the moment, the logger name of inner classes is OuterClass$InnerClass. Because of that, the logging level of OuterClass isn't inherited by InnerClass at the moment. If LoggerFactory changed the logger name to OuterClass.InnerClass instead, InnerClass would inherit the logging level of OuterClass which seems intuitively correct. I'd suggest to accept both $InnerClass and .InnerClass style in logback configurations for compatibility and usability reasons. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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