Spring boot embedded tomcat logs

Question

i'm using spring boot embedded tomcat with spring boot 1.5.9 , im also using Log4j2.

recently i exerience problems during load, so i want to understand better the tomcat logs [Not the access Logs] , i tried (in application.properties) :

logging.level.org.apache.tomcat: INFO
logging.level.org.apache.catalina: INFO

but none of the above worked. is there any other way to achieve it ?

Answer 1

Found it !! You are now able to see the internal Logs of Embedded Tomcat in your App's Log4j log file with 3 easy steps:

1] add to your pom:

 <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-jul</artifactId>
     </dependency>

2] add to your running arg a new JVM param , e.g:

java -Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager -jar target/demo-0.0.1-SNAPSHOT.jar

3] add to your application.properties:

logging.level.org.apache=DEBUG

Enjoy Life ! :)

Explaination: the problem is because Log4j log levels is not propagated into JUL (which is the actual Logging way Embedded tomcat use) so the above achieves this connection with JUL and Log4j log levels.

Reference: After reading the Spring boot 1.5.10 release notes (which is not required for the solution) i saw the new documentation that shed light how to achive it and explaination about it:

https://github.com/spring-projects/spring-boot/issues/2923#issuecomment-358451260

Answer 2

I struggled a lot,and didnt find anything of my help.Utlimately I had build "WAR" out of my spring boot application.Deploy it to tomcat instance and followed below steps,which redirected all the internal tomcat logs(JULI) logs to my application log file.

1. Delete existing JULI library (CATALINA_HOME/bin/tomcat-juli.jar file) and the existing Tomcat Java Logging configuration file (CATALINA_HOME/conf/logging.properties).

2. Download JULI Log4j Tomcat library (tomcat-juli.jar) from the Tomcat downloads’ Extras section (http://tomcat.apache.org/download-70.cgi). Place the downloaded file to CATALINA_HOME/bin directory.

3. Download Tomcat JULI adapters library (tomcat-juli-adapters.jar) from the Tomcat downloads’ Extras section. Place this file in the CATALINA_HOME/lib directory.

4. Download Log4j (version 1.2 or later), and place the downloaded library file to CATALINA_HOME/lib directory.

5. Create the Log4j configuration file at the following location: CATALINA_HOME/lib/log4j.properties. Check below log4j configuration matching the default Java Logging configuration.

6. Restart Tomcat.

Log4j configuration File Matching the Default Tomcat Logging Settings:

log4j.rootLogger=INFO, CATALINA
//Define all the appenders log4j.appender.CATALINA=org.apache.log4j.DailyRollingFileAppender
log4j.appender.CATALINA.File=${catalina.base}/logs/catalina.
log4j.appender.CATALINA.Append=true log4j.appender.CATALINA.Encoding=UTF-8

//Roll-over the log once per day
log4j.appender.CATALINA.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.CATALINA.layout = org.apache.log4j.PatternLayout

log4j.appender.CATALINA.layout.ConversionPattern = %d [%t] %-5p %c- %m%n
log4j.appender.LOCALHOST=org.apache.log4j.DailyRollingFileAppender
log4j.appender.LOCALHOST.File=${catalina.base}/logs/localhost.
log4j.appender.LOCALHOST.Append=true log4j.appender.LOCALHOST.Encoding=UTF-8
log4j.appender.LOCALHOST.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.LOCALHOST.layout = org.apache.log4j.PatternLayout
log4j.appender.LOCALHOST.layout.ConversionPattern = %d [%t] %-5p %c- %m%n
log4j.appender.MANAGER=org.apache.log4j.DailyRollingFileAppender
log4j.appender.MANAGER.File=${catalina.base}/logs/manager.
log4j.appender.MANAGER.Append=true log4j.appender.MANAGER.Encoding=UTF-8
log4j.appender.MANAGER.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.MANAGER.layout = org.apache.log4j.PatternLayout
log4j.appender.MANAGER.layout.ConversionPattern = %d [%t] %-5p %c- %m%n
log4j.appender.HOST-MANAGER=org.apache.log4j.DailyRollingFileAppender
log4j.appender.HOST-MANAGER.File=${catalina.base}/logs/host-manager.
log4j.appender.HOST-MANAGER.Append=true log4j.appender.HOST-MANAGER.Encoding=UTF-8
log4j.appender.HOST-MANAGER.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.HOST-MANAGER.layout = org.apache.log4j.PatternLayout
log4j.appender.HOST-MANAGER.layout.ConversionPattern = %d [%t] %-5p %c- %m%n
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Encoding=UTF-8
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern = %d [%t] %-5p %c- %m%n

//Configure which loggers log to which appenders
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].
[localhost]=INFO,
 LOCALHOST
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].
[localhost].[/manager]=INFO,MANAGER
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].
[localhost].[/host-manager]=
INFO, HOST-
MANAGER

You can also check a adapter avaiable on GIT @ link

In your spring boot application,you can make changes like adding and removing jars,folder from embedded Tomcat server Or even adding custom config files to it using TomcatEmbeddedServletContainerFactory.class ,of spring boot.

Answer 3

Please refer to this url which contains common application properties which also includes application logging properties and tomcat level logging properties. Whether you use yaml or properties file, spring boot uses this configuration to bootstrap the application. Search for below configuration items.

# LOGGING
logging.config= # Location of the logging configuration file. For instance `classpath:logback.xml` for Logback
logging.exception-conversion-word=%wEx # Conversion word used when logging exceptions.
logging.file= # Log file name. For instance `myapp.log`
logging.level.*= # Log levels severity mapping. For instance `logging.level.org.springframework=DEBUG`
logging.path= # Location of the log file. For instance `/var/log`
logging.pattern.console= # Appender pattern for output to the console. Only supported with the default logback setup.
logging.pattern.file= # Appender pattern for output to the file. Only supported with the default logback setup.
logging.pattern.level= # Appender pattern for log level (default %5p). Only supported with the default logback setup.
logging.register-shutdown-hook=false # Register a shutdown hook for the logging system when it is initialized.

server.tomcat.accept-count= # Maximum queue length for incoming connection requests when all possible request processing threads are in use.
server.tomcat.accesslog.buffered=true # Buffer output such that it is only flushed periodically.
server.tomcat.accesslog.directory=logs # Directory in which log files are created. Can be relative to the tomcat base dir or absolute.
server.tomcat.accesslog.enabled=false # Enable access log.
server.tomcat.accesslog.file-date-format=.yyyy-MM-dd # Date format to place in log file name.
server.tomcat.accesslog.pattern=common # Format pattern for access logs.
server.tomcat.accesslog.prefix=access_log # Log file name prefix.
server.tomcat.accesslog.rename-on-rotate=false # Defer inclusion of the date stamp in the file name until rotate time.
server.tomcat.accesslog.request-attributes-enabled=false # Set request attributes for IP address, Hostname, protocol and port used for the request.
server.tomcat.accesslog.rotate=true # Enable access log rotation.
server.tomcat.accesslog.suffix=.log # Log file name suffix.
server.tomcat.additional-tld-skip-patterns= # Comma-separated list of additional patterns that match jars to ignore for TLD scanning.
server.tomcat.background-processor-delay=30 # Delay in seconds between the invocation of backgroundProcess methods.
server.tomcat.basedir= # Tomcat base directory. If not specified a temporary directory will be used.
server.tomcat.internal-proxies=10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\\
        192\\.168\\.\\d{1,3}\\.\\d{1,3}|\\
        169\\.254\\.\\d{1,3}\\.\\d{1,3}|\\
        127\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\\
        172\\.1[6-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\\
        172\\.2[0-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\\
        172\\.3[0-1]{1}\\.\\d{1,3}\\.\\d{1,3} # regular expression matching trusted IP addresses.
server.tomcat.max-connections= # Maximum number of connections that the server will accept and process at any given time.
server.tomcat.max-http-post-size=0 # Maximum size in bytes of the HTTP post content.
server.tomcat.max-threads=0 # Maximum amount of worker threads.
server.tomcat.min-spare-threads=0 # Minimum amount of worker threads.
server.tomcat.port-header=X-Forwarded-Port # Name of the HTTP header used to override the original port value.
server.tomcat.protocol-header= # Header that holds the incoming protocol, usually named "X-Forwarded-Proto".
server.tomcat.protocol-header-https-value=https # Value of the protocol header that indicates that the incoming request uses SSL.
server.tomcat.redirect-context-root= # Whether requests to the context root should be redirected by appending a / to the path.
server.tomcat.remote-ip-header= # Name of the http header from which the remote ip is extracted. For instance `X-FORWARDED-FOR`
server.tomcat.uri-encoding=UTF-8 # Character encoding to use to decode the URI.

Answer 4

Default configurations are provided for Java Util Logging, Log4J, Log4J2 and Logback. In each case loggers are pre-configured to use console output with optional file output also available

refer this link : https://stackoverflow.com/questions/31939849/spring-boot-default-log-location/31939886

The embedded tomcat in spring boot internally echoes logs to console. The default log configuration will echo messages to the console as they are written. So until you explicitly specify a file as you described, it stays in the Console.

From the spring boot logging doc.

You can custmize the logging as per your need.

Answer 5

The package for the embeded tomcat is org.springframework.boot.context.embedded.tomcat So adding this to your application.properties file

logging.level.org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer=INFO

Answer 6

For slf4j and Spring Boot 2 hide exceptions from Tomcat and handle them by yourself:

• Add to pom:

  <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>jul-to-slf4j</artifactId>
      <version>${slf4j.version}</version>
  </dependency>
  

• Add to config:

  @PostConstruct
  void postConstruct() {
      SLF4JBridgeHandler.install();
  }
  

• Add to application.yaml

  logging:
      level:
        org.apache.catalina: off
  

• Handle exception in ErrorController

  @Controller
  @Slf4j
  public class ErrorController implements 
                org.springframework.boot.web.servlet.error.ErrorController {
      private static final String ERROR_PATH = "/error";
  
     @Autowired
     private ErrorAttributes errorAttributes;
  
     @Override
     public String getErrorPath() {
        return ERROR_PATH;
     }
  
     @RequestMapping(ERROR_PATH)
     public ModelAndView error(HttpServletRequest request) {
         return processException(errorAttributes.getError(new ServletWebRequest(request)));
     }
  }