October 2017 - logback-user

Logback => TLS/SSL => Syslog ?
by Otis Gospodnetić 21 Feb '19

21 Feb '19

Hi, Does Logback support sending logs to Syslog servers via TLS/SSL? I have a feeling Logback doesn't have a SyslogAppender that can send data using TLS. I say that because I don't see a mention of "syslog" on http://logback.qos.ch/manual/usingSSL.html and I see http://jira.qos.ch/browse/LOGBACK-890 that mentions TLSSyslogAppender, but it looks like this never ended up in Logback. I've only found it committed here: https://github.com/balabit/logback/commit/e0d89de2536e0925a6c816a50793f6a74… Could anyone please clarify? Thanks, Otis -- Monitoring * Alerting * Anomaly Detection * Centralized Log Management Solr & Elasticsearch Support * http://sematext.com/

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SizeBasedTriggeringPolicy + RollingFileAppender bizarrely slow in certain cases on Windows
by mpderbec 24 Oct '17

24 Oct '17

We use the SizeBasedTriggeringPolicy and RollingFileAppender. We had reports of our application server on Windows slowing to a crawl, and after many hours debugging, discovered that it was the /content of the current log file/ that was causing each of LogBack's write operations to take several hundred milliseconds (instead of 5ms or so). Our log output is relatively verbose, so that meant our application was taking minutes to do simple operations if it was under load. It was a very rare occurrence, but when it happened, our application became useless. We could easily reproduce or eliminate the slowness by altering the content at the beginning of the log file. Namely, if we take all the dollar-sign characters ($) out of the first 200 lines, the slowness does not occur. Add them back and the slowness comes back immediately. We were able to do this without restarting our application, just by altering the content on the fly with Notepad++. I know this sounds crazy. So we created a tiny Java project that mimicks the calls that Logback makes with this triggering policy and appender. Namely, it retrieves the file length while simultaneously keeping a FileOutputStream object open for writing. It's the File.length() call that becomes slow. The project is posted here <https://github.com/seeq12/log-slowness> . You can see the code and read our commentary here <https://github.com/seeq12/log-slowness/blob/master/src/ShowLogSlowness.java> . It's pretty easy to clone the repo and run the Java command if you want to see this for yourself. This reproduced on 100% of our Windows environments (desktops, laptops, VMs). It does not reproduce on OSX. You can diff the two "seed" log files (fast.log and slow.log) and you'll see how little they differ. This is obviously not Logback's fault but Logback (and other logging libraries) would suffer nonetheless. I'm posting to this mailing list in case anyone has seen this and can offer insight / advice. -- Sent from: http://logback.10977.n7.nabble.com/Users-f3.html

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separate task log files (slf4j + logback)
by Денис Матвеев 18 Oct '17

18 Oct '17

>> You can separate logs in filtering/routing software like I wrote: >> Flume, Fluentd, Logstash, Kafka, or whatever popular today. Direct >> events to intermediate agent that able to split and transform logging >> events. Answer with quote from https://logback.qos.ch/manual/layouts.html "TCP implementations will follow a general principle of robustness: be conservative in what you do, be liberal in what you accept from others. —JON POSTEL, RFC 793" :-)

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separate task log files (slf4j + logback)
by Денис Матвеев 18 Oct '17

18 Oct '17

Yes, maybe I'm trying to use loggers for dumps, but I wanted to use the existing functionality of log-services (Rolling, Sizing, Layout etc.). What's bad about it? Yes, of course, different names are used for different loggers. Having created a Logger object with a specific name, I already set some logical separation of entities in my program. For example AAA.BBB.Loading - everything is written in this logger during loading, and there is a lot and this is a detailed logger, which describes all the our system configuration files, their versions, file sizes, success load, criticality of a file. Among them may be INFO, WARN or ERROR messages. Next example, AAA.BBB.startstop - this logger records only the events of launching and unloading the application, so that you can always immediately see when and how many times it was overloaded or may be crashed. I see only the possibility to explicitly assign a binding to these names of the appropriate files in the configuration file. But I wanted to configure the configuration file so that it did not have to be changed by hand when adding a new logger to the program code. About MDC, I'm not too lazy to write MDC calls But I need every call to the "log.out" method between two MDC.put and MDC.remove eg public class myLog { ... private Logger log; ... public void myLogOut(String msg) { MDC.put("logger_id", log.getLoggerName); log.out(msg); MDC.remove("logger_id"); } } but in https://logback.qos.ch/manual/mdc.html write "Please note that MDC as implemented by logback-classic assumes that values are placed into the MDC with moderate frequency". >> Logger names are capable to be filtered in hierarchical way. Your >> thoughts to use them differently are ill minded...Filtering in hierarchical way is very good and useful feature - but now it is implenents only "vertical" (level) separation. When I create a named Logger object in the program, I already also enclose this "horizontal" (logic) separation and I want to use it immediately. Thanks to Ceki Gulku for explain and example SiftingAppender.

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separate task log files (slf4j + logback)
by Денис Матвеев 18 Oct '17

18 Oct '17

The MDC does not help when I have several different long-running tasks in one thread and I just want to immediately separate their logs. It seems that this is not such a fantastic wish. It is much easier to separate logical logging flows at once, than to filter them later in databases. The amount of data is large, logs per day can accumulate several hundred megabytes. It turns out that we will have to write our own implementation of such a log.

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separate task log files (slf4j + logback)
by Денис Матвеев 17 Oct '17

17 Oct '17

Hello! I began to consider the possibility of logging in a new major Java application and so far I could not find (jul, logback) how to do the following: - Loggers for different subtasks are created inside the program (LoggerFactory.getLogger(logName)), I want the logName to be the name of the log file, the number of subtasks is unknown in advance, i.e. so you do not have to edit the configuration file when writing the next subtask, which explicitly assigns the log name and correlates it with some file. Is it possible to register this once at the configuration file level so that it does not have to be changed in the future? Thanks for your job. Best regards Denis Matveev Russia Ekaterinburg

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Query on custom selector
by Abhishek Gupta 17 Oct '17

17 Oct '17

Hi, I want to create custom context selector for logging separation using different logback file Do you have any concrete example for that apart from JNDI selector? Thanks, Abhishek

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