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Logback Spring - Change log levels during runtime using an external yaml file outside of the jar

Inside of my logback-spring.xml file, I am able to change the log levels, and it's able to autodetect changes when I include auto scan. Looks like this:
<configuration debug="true" scan="true" scanPeriod="10 seconds">
However, I want to keep all of my log levels in an external yaml configuration file and I don't want to have to restart the server to detect those changes. Is there a way to use an external yaml file to define log levels and use logback autoscan? Or should I be looking at a completely different way of going about it?

You can do that in application.yml, try adding the following settings
spring:
logging:
level:
org.springframework.web: DEBUG
com.company.package: DEBUG
You can also specify pattern if you like.

Springboot how to rotate log files on the server restart

Springboot how to rotate log files on the server restart.
I have the below entries
# LOGGING
logging.level.org.springframework.web=WARN
logging.level.org.hibernate=WARN
logging.file=/var/log/apps/myapp.log
I can't find any details here:
https://docs.spring.io/spring-boot/docs/1.5.9.RELEASE/reference/html/common-application-properties.html

As per the following link in application.properties regarding log files, the following are the configurations.
https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html
logging.file.max-history=0 # Maximum of archive log files to keep. Only supported with the default logback setup.
logging.file.max-size=10MB # Maximum log file size. Only supported with the default logback setup.
Apart from the above, you can also check below the configuration based upon the server configured.
server.tomcat.accesslog.rotate=true # Whether to enable access log rotation.
server.undertow.accesslog.rotate=true # Whether to enable access log rotation.
I would suggest to use Slf4j along with logback. You need to configure logback.xml and you can configure rolling file appender.

You can add the custom log configuration with logback-spring.xml.
The various logging systems can be activated by including the appropriate libraries on the classpath and can be further customized by providing a suitable configuration file in the root of the classpath or in a location specified by the following Spring Environment property: logging.config.
https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-logging.html#boot-features-custom-log-configuration

I got a rotation policy with setting a limit to the log file size and the same for the backup.
logging.file.name=/path/log/file
logging.file.max-size=10MB
logging.file.total-size-cap=10MB
IMPORTANT: it will keep just a backup file.

I dont know your exact scenario but you can do this by passing env_variable when you start a server.. like your build version number and use that in your property file
spring-boot:run -Dbuild.number=1.x
And you may use this like
# LOGGING
logging.level.org.springframework.web=WARN
logging.level.org.hibernate=WARN
logging.file=/var/log/apps/myapp-${build.number}.log
Dont forgot to increment number everytime.

Log4J DailyRollingFileAppender fails to roll over

I am using web-based application along with Log4J API for logging purpose.
In Log4J, I am using DailyRollingFileAppender to create a new log file for logging on each day.
here is my log4j properties file configuration
log4j.logger.org.apache.cxf=ERROR
log4j.rootLogger=INFO, jtiServiceAppender
log4j.appender.jtiServiceAppender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.jtiServiceAppender.File=${catalina.home}/logs/jti/ilume-mw${logfilename}-app.log
log4j.appender.jtiServiceAppender.DatePattern='.'yyyy-MM-dd
log4j.appender.jtiServiceAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.jtiServiceAppender.layout.ConversionPattern=%d{dd.MM.yyyy HH\:mm\:ss} %-5p %t [%C{1}]\: %m%n
Problem:
In my case, the log files are not created for each day. For the same when I checked my tomcat server log I have observed that I am getting an error as
log4j:ERROR Failed to rename [D:\ilume-mwtmp0-app.log] to
[D:\ilume-mwtmp0-app.log.2019-07-09].
I have also referred the below link however still, I did not find a proper solution to my case.
Link : enter link description here
Any help or suggestion to solve this logging problem will be highly appreciated as it's been a couple of days and I am still not able to get any proper solution to this problem. 

When adding appender-ref in logger tag, it throws renaming error. When adding appender-ref in root tag, it never throws that error.
Above is from below link. It seems same error and might help.
log4j:ERROR Failed to rename
Other than above, please check if there is permission issue at the directory where file needs to be renamed.

Adding AsyncAppender to log4j.properties

I am trying to add AsyncLogger to log4j.properties. I have found examples of adding AsyncLogger to lo4j.xml file, but not to log4j.properties. Can you please let me know how to add it. Please provide a sample log4j.properties entry for AsyncLogger.
Thanks

You can't AsyncAppenders need to be configured by code or XML

Log4j doesn't log INFO Level

I have the following log4j.properties file, for an application deployed in WebSphere Portal:
log4j.rootLogger=DEBUG, InfoAppender, DebugAppender
log4j.appender.InfoAppender=org.apache.log4j.RollingFileAppender
log4j.appender.InfoAppender.Threshold=INFO
log4j.appender.InfoAppender.File=C:/info.log
log4j.appender.InfoAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.InfoAppender.layout.ConversionPattern=%d %p [%c] - %m%n
log4j.appender.DebugAppender=org.apache.log4j.RollingFileAppender
log4j.appender.DebugAppender.Threshold=DEBUG
log4j.appender.DebugAppender.File=C:/debug.log
log4j.appender.DebugAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.DebugAppender.layout.ConversionPattern=%d %p [%c] - %m%n
When I code, I define the logger at class level:
private static Logger logger = Logger.getLogger(IWannaLogThis.class);
And I log INFO messages with this:
logger.info(theObjectToLog);
When I deploy my application, the debug.log file gets everything I log with logger.debug() but ignores everything I write with logger.info(). On the other side, the info.log file keeps empty.
The weirdest thing is that in debug.log and info.log appears some INFO and DEBUG messages made by some JARS (like Hibernate Validator) I had in the classpath, but just ignores everything I try to log in my code.
Any ideas?

This is most likely a classloading-related problem. WebSphere Portal uses Log4J internally, so I'm guessing that you end up using WebSphere Portal's provided Log4J JAR file as well as its own Log4J properties.
You can verify that by adding the following to the JVM arguments of the server instance:
-Dlog4j.debug=true
And then inspect the SystemOut.log file. Log4J will spit out lots of tracing information about the configuration file(s) it reads.
The best way to avoid this is to do the following:
Bundle the Log4J JAR file with your application.
Associate a Shared Library with the server. In that Shared Library, place your Log4J configuration file.
As an alternative to step 2, you can bundle your Log4J configuration file with the application itself, however that would carry its own drawbacks (for example, having to repackage your application whenever you perform a Log4J configuration change).

Another common problem is that the JARs you have in your classpath also use log4j and also have their own appenders set. So depending on the settings that they use, and the packages that your classes reside in, this may lead to the problem you describe.
So:
Make sure that your package names are unique and not used by any of the third party libraries.
Check the log4j settings in all libraries in your classpath. They should not contain general settings which override yours.
Make sure your loggers use your log4j.properties (you can be sure if changes you make in your file affect your loggers as expected).
If you can, make sure that your log4j stuff loads last, in case any of the third party libs reset the configuration. They shouldn't, but who can stop them.
Normally, it should be one of these things. Post more explicit example if it doesn't work.
Good luck!

What I have done in the past is set specific logs for the classes I want to log. It sounds like you can try setting your root logger to INFO and see if that gets you the messages you want. Here's a little bit of my log4j property file. I set a logger for each class and assign it to my "data" appender, which defines the log layout. In the loggers I specify specific classes I want to log and set their Log level individually. Any class that logs that is not defined in the Loggers I have use the default log level for the rootCategory.
log4j.rootCategory=INFO, rollingFile, stdout
#GetData Loggers
log4j.logger.com.myapp.data=INFO, data
log4j.logger.com.myapp.data.SybaseConnection=DEBUG, data
log4j.logger.com.myapp.data.GetData=ERROR, data
# data appender
log4j.appender.data=org.apache.log4j.RollingFileAppender
log4j.appender.data.layout=org.apache.log4j.PatternLayout
log4j.appender.data.File=c\:\\Program Files\\MyApp\\logs\\MyApp-data.log
log4j.appender.data.Append=true
log4j.appender.data.layout.ConversionPattern=[%d{ISO8601}]%5p%6.6r[%t]%x - %C.%M(%F:%L) - %m%n

you root logger opens the log properties in the debug mode,
use INFO instead of DEbug in the first line of your properties file.