I've been given the requirement that the first line of my log files must begin with a specific header. This header should specify that this current file is newly created. Even when log files are automatically rotated.
It seems odd but it is in the specification for the project.
Environment info:
App Server: Glassfish V2
Logging: SL4J
I think you're going to have to subclass the relevant appender and add your own code to do this.
The log file is not written by slf4j. It is written by the logging system behind the facade. The solution will depend on what that logging system is.
Unless that logging system has an existing log file appender that does this, you will need to write a custom appender (using the appropriate API, etc) that writes the header each time it opens a new log file.
Related
I have an application running in Wildfly 8.2.1. In addition to the server.log file in the log directory, my application creates and uses other log files too (also in the log directory). They all end in .log. This is dynamic and programmatic using org.apache.log4j.FileAppender, since the names, contents, and number of files differs from one client to the next.
What I'd like is for Wildfly to automatically rotate these log files too in addition to its own (i.e. server.log). I see in standalone.xml there is a periodic-rotating-file-handler tag with a file subtag that has a path attribute. From reading the Wildfly logging documentation, it seems like I can't use wild cards here? So, path="*.log"? Is this true? If so, how can I achieve the end goal of Wildfly automatically rotating my log files instead of doing it myself?
If you'd like to rotate log files you'd need to use a rotating file handler. The periodic-rotating-file-handler will only rotate it's own file not other files associated with other file handlers.
Since you seem to be creating a log4j file appender have a look at the org.apache.log4j.RollingFileAppender.
I have 4 appllications (ear) on my WAS. I need them to write in SystemOut.log some sign. I.e each application must write to log file its own sign. For example:
[16.01.17 3:50:05:592 GMT+05:00] ADMIN 000005e0 SubsystemMess I com.docflow.core.integration.jms.SubsystemMessageListener onMessage_aroundBody0 Subsystem integration message ID:f5392a5ec3b3f41502095b00110a134f0000000000000001 of type DP_EKS_BANK_GUARANTEE_RECEIVED process finished
Here ADMIN is sign of the application.
How i can do that?
It's not possible to adjust the default logging format in this way. Your options would be to use java.util.logging.Logger with a particular name (to replace the "SubsystemMess" part) or to use a separate logging package and configure it to log to a separate file.
Look at log4j and configuring each app's log4j to go to a different file.
Log4j's file appender can be configured to also include timestamp and more.
The only catch is you can't configure it from WAS's admin console then.
Note that java.util.Logger writes to the trace.log. If you use a different logger name, it will list as such in the same trace.log file. Upside is you can now configure it from the admin console.
One potential solution could be to switch to HPEL logging. Then you could query log entries for your given application using logviewer, like:
logViewer.sh -includeExtensions appName=PlantsByWebSphere
I know that it is not exactly what you are looking for, but maybe it will be sufficient for your needs.
My app deployed on Tomcat uses log4j to write a log file. If I delete that file, then the app does not recreate it. I also tried to recreate it manually, but it remains always empty. Is there any way to delete the log file (not from the app), create a new one in the same path with the same name, and that it can be written by the application?
Is there any way to delete the log file (not from the app), create a new one in the same path with the same name, and that it can be written by the application?
Nope. You need to get the application itself to restart logging.
The problem is that the log4j appender still has a handle for the deleted file, and will continue to write to it ... unaware that it has been deleted.
A better approach would be to have the application itself take care of "rotating" the logfile. Look at the classes that implement the log4j Appender interface for some ideas.
What is the fastest async way to log to file in Vert.x?
The aim is to write logs from loggers from different classes (i.e. Class1, Class2 etc) to 1 file (something like 'console.log')
Vert.x uses the JDK bundled JUL logging framework to avoid shipping additional dependencies. However it allows to append a custom logger implementation.
Assuming that you want to stick to the default logging facility, customizing the log handler would then be as easy as droping a logging file and referencing it through the java.util.logging.config.file system property:
For example you can drop the logging configuration file under a config directory under the root path of your (fat) jar which may look as follows:
handlers = java.util.logging.MyFileHandler
config =
#...
You should then refrence that file in a system property as follows when starting your Vert.x application:
-Djava.util.logging.config.file=config/logging.properties
You can then access the Logger object in your classes as follows:
Logger logger = LoggerFactory.getLogger("some.package.MyClass");
Use that logger to log messages that will be handled by the configured handler(s):
logger.info("some informative message");
Note the use of a custom log handler in the properties file to emphasis the possibily of appending your own handler (which may extend the default FileHandler).
Check the Vert.x documentation for more informations on how to use explore the logging feature.
Most of loggers are async from the beginning , i.e. they are not write information immediately. Logs are stored into buffer, which is flushed by timeout or when it is full. So slf4j + log4 is good enough for most cases.
I know it is possible to reload log4j's xml configuration while the application is running, but the searching I've done only shows how to do this when the XML config file is edited manually via a text editor.
I want to be able to dynamically change the level of the root logger in my application via a web page and persist that change to the log4j XML configuration, so I won't have to change the log level again if I restart the application. Is it possible to do this, or can the log4j XML file only be updated manually?
I am using log4j 1.2 in my application.
Many thanks in advance!
for any chump who finds themselves stuck dealing with this, it is possible to write out the data as properties using
org.apache.log4j.config.PropertyPrinter;
You can acheive this by PropertyConfigurator configure and watch.
Read the configuration file configFilename if it exists. Moreover, a thread will be created that will periodically check if configFilename has been created or modified. The period is determined by the delay argument. If a change or file creation is detected, then configFilename is read to configure log4j.