I have done log4j configuration properly and working fine to write logs from my application, i used log4j.XML in spring web application.
But the problem is if the current log file directory is crashed i need to write logs in some other directory to take logs during that time.
Give me any suggestion to meet above requirements.
Related
I use logback as well as log4j2 in my java web apps for logging. So far, I've setup log rotation (and purging) from within logback and log4j2 but now I intend to use logrotate at an infrastructure level since there are lots of services (in other languages as well) and it's relatively easier to maintain one common way of handling log files.
While doing a POC, I setup the java app to write logs to a file application.log and also setup logrotate with a size criteria (of 1 MB). As expected, when the file size reached 1 MB, the log file was rotated by way of moving it to another file named application.log.1. At this point, I expected the java app to continue writing new logs to application.log file. However, the logs kept getting written in the rotated file i.e. application.log.1.
This makes me wonder whether the component within logback/log4j2 that writes the log content in the file tracks the file by its name or something else like an inode number or a file handler. Since the original active log file was not deleted but just moved with a new name.
I'm aware of the copytruncate option in logrotate which creates a copy of the active log file and then truncates the active log file, but I don't want to use this as this can lead to loss of log events for agents running on the machines which pushes the logs to systems like Elasticsearch and CloudWatch. Since truncate can happen before the agents have processed all the log entries.
How can I get the logging component to always write logs to a file named application.log even after the original file underneath gets moved?
The logging framework opens the file for write and leaves the OutputStream open until the application ends or the file is rolled over or similar. On a Unix system you can move the file, rename it, or delete it but the application will keep writing to it. The application has no way of knowing the file was externally manipulated.
If you are using Log4j 2 you should use the RollingFileAppender and use the DeleteAction to delete old files.
Hi I'va the next doubt and I want to know if it's possible to implement. I have some wars deployed in a wildfly/jboss server. For some reason, that server doesn't log anything and the administrator of it seems that doesn't want to do his job. So I was wondering if there's a way to see the log of each war in a browser by a frontend design by me.
I think that I can add in each war a log file, but, there's possible to access each file from a browser and see each one? Also there's no need to be in real time.
Help would be appreciated.
Thanks.
I usually clear log files when I'm in developement mode and I need to have a fresh start to focus only on things I have to test.
If I clear a log file in linux (have not tested Windows), logback stops to write to that file
Maybe it's something about open handlers and file descriptors in linux.
How can I recover the situation without restarting the application?
Is it possibile to have an appender that can automatically recover this situation?
While your application is running (and Logback within your application has an open handle to the log file) ...
You won't be able to delete the file on Windows
You will be able to delete the file on Linux but as far as Logback is concerned the file still exists until Logback closes that open file handle. So, Logback won't know that the the file has been deleted but since the file has been deleted Logback cannot actually write anything to disk and this situation remains until Logback is re-initialised (and your FileAppender recreates the file). Typically, this will be done on application startup.
There's an open issue against Logback requesting a change in Logback's behaviour in this situation.
If you goal here is to have log output which focusses on recent-activity-only then you could define a rolling file appender with a minimal size and no history just to retain the (for example) last 1MB of data, this might help offer some focus on recent events only.
Alternatively, you'll have to:
Vote for this issue
Use grep/awk to find the relevant aspects of your log file (you can easily grep on timestamps) even if they are in a log file which contains the last few hours of log events
Ease the burden of restarting your application in this scenario by writing a simple script which does something like: (1) stop application; (2) delete log file; (3) start application
I'm developing a Java Swing application and enabled them with Java web start feature.
Currently, i'm logging the events in a log file and saving them in jre folder.
Is this a correct way of doing?
If not where can i save the log files?
Note : i've asked the same question in other forum, but unable to get any suggestions.
Better option is to store the log files in System.getProperty("user.home").
I am facing a problem with file upload.I have used Apache Commons
servlet file upload for uploading the file. Though the file is getting
uploaded and the data is getting stored on the local server(http://
127.0.0.1:8888/_ah/admin/datastore) but it is not going to the Google
App Engine datastore.
What I am doing is loading
the file as a stream and immediately parsing the stream and creating
datastore entities with the data. I am not actually trying to save the
file. In the local server it works. It even works when I try to access
the local server from another machine. However it does not work when I
deploy it to Appengine using the Google Pluggin for Eclipse. My parsing
code depends on resource files which are under the web-inf directory.
Is it possible these resource files are not getting uploaded and is
there a way to check what files are uploaded on Appengine?
Whatever's in your .war is going up into AppEngine. I don't see how parts of it will be selectively excluded. What's more likely is that your application is depending on stuff that is lurking SOMEwhere on your PC but not included in that .war file.
However, shouldn't your application be checking for those resources and throwing exceptions if they are not found? If it's failing silently, I'd consider that a design flaw.
Logging a lot may help you debug the problem. You can look at your program's logs via the AppEngine console. I recommend more error checking and logging.
Something else to check for is to not be running the version of your software you think you are. There's a kind of versioning mechanism that allows you to deploy different concurrent versions of your and only one will be actually accessible. One of the things you should be logging and/or making otherwise accessible is some version information (perhaps even including a build timestamp) for your app's build.
The files in the .war folder are executed in the app engine and the others are uploaded. What you need to verify is the path you have set and the path of you source java file and the file you are reading. You cannot use the local file system path in app engine. You need to include the file in your project