@ -9,29 +9,21 @@ Print the logger information, update the logger level
```bash
[arthas@2062]$ logger
name ROOT
class ch.qos.logback.classic.Logger
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
level INFO
effectiveLevel INFO
additivity true
codeSource file:/Users/hengyunabc/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar
appenders name CONSOLE
class ch.qos.logback.core.ConsoleAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
target System.out
name APPLICATION
class ch.qos.logback.core.rolling.RollingFileAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
file app.log
name ASYNC
class ch.qos.logback.classic.AsyncAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
appenderRef [APPLICATION]
name ROOT
class ch.qos.logback.classic.Logger
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
level INFO
effectiveLevel INFO
additivity true
codeSource jar:file:/home/scrapbook/tutorial/demo-arthas-spring-boot.jar!/BOOT-INF/lib/logback-classi
c-1.1.11.jar!/
appenders name CONSOLE
class ch.qos.logback.core.ConsoleAppender
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
target System.out
...
```
#### View logger information for the special name
@ -40,18 +32,19 @@ Print the logger information, update the logger level
```bash
[arthas@2062]$ logger -n org.springframework.web
name org.springframework.web
class ch.qos.logback.classic.Logger
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
level null
effectiveLevel INFO
additivity true
codeSource file:/Users/hengyunabc/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar
name org.springframework.web
class ch.qos.logback.classic.Logger
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
level null
effectiveLevel INFO
additivity true
codeSource jar:file:/home/scrapbook/tutorial/demo-arthas-spring-boot.jar!/BOOT-INF/lib/logback-classi
c-1.1.11.jar!/
```
Please write down your classLoaderHash here, in the case here, it's ` 2a139a5 5`. It will be used in the future steps.
Please write down your classLoaderHash here, in the case here, it's ` 5674cd4d `. It will be used in the future steps.
Note: Please replace `<classLoaderHash>` with your classLoaderHash above, then execute the commands manually in the following steps:
@ -62,42 +55,32 @@ Note that the hashcode changes, you need to check the current ClassLoader inform
if you use`-c`, you have to manually type hashcode by `-c <hashcode>` .
```bash
$ logger -c 2a139a5 5
$ logger -c 5674cd4d
```
For classloader with only one instance, it can be specified by `--classLoaderClass` using class name, which is more convenient to use.
`logger --classLoaderClass sun.misc.Launcher$App ClassLoader`{{execute T2}}
`logger --classLoaderClass org.springframework.boot.loader.LaunchedURL ClassLoader`{{execute T2}}
```bash
[arthas@2062]$ logger --classLoaderClass sun.misc.Launcher$AppClassLoader
name ROOT
class ch.qos.logback.classic.Logger
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
level DEBUG
effectiveLevel DEBUG
additivity true
codeSource file:/Users/hengyunabc/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar
appenders name CONSOLE
class ch.qos.logback.core.ConsoleAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
target System.out
name APPLICATION
class ch.qos.logback.core.rolling.RollingFileAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
file app.log
name ASYNC
class ch.qos.logback.classic.AsyncAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
appenderRef [APPLICATION]
[arthas@2062]$ logger --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader
name ROOT
class ch.qos.logback.classic.Logger
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
level INFO
effectiveLevel INFO
additivity true
codeSource jar:file:/home/scrapbook/tutorial/demo-arthas-spring-boot.jar!/BOOT-INF/lib/logback-classi
c-1.1.11.jar!/
appenders name CONSOLE
class ch.qos.logback.core.ConsoleAppender
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
target System.out
...
```
* PS: Here the classLoaderClass in java 8 is sun.misc.Launcher$AppClassLoader, while in java 11 it's jdk.internal.loader.ClassLoaders$AppClassLoader. Currently katacoda using java 8.
The value of `--classloaderclass` is the class name of classloader. It can only work when it matches a unique classloader instance. The purpose is to facilitate the input of general commands. However, `-c <hashcode>` is dynamic.
#### Update logger level
@ -109,16 +92,18 @@ The value of `--classloaderclass` is the class name of classloader. It can only
update logger level success.
```
PS: Here it will come up with an error message in tutorial, we have to specify the classloader.
#### Speecify classloader to update logger level
By default, logger command will be executed under SystemClassloader, if the application is a traditional `war` , or using spring boot fat jar, then it needs to specify classloader。
You can first use `sc -d yourClassName` to check specified classloader hashcode, then specify classloader when updating logger level:
`logger --classLoaderClass sun.misc.Launcher$App ClassLoader --name ROOT --level debug`{{execute T2}}
`logger --classLoaderClass org.springframework.boot.loader.LaunchedURL ClassLoader --name ROOT --level debug`{{execute T2}}
```bash
[arthas@2062]$ logger --classLoaderClass sun.misc.Launcher$App ClassLoader --name ROOT --level debug
[arthas@2062]$ logger --classLoaderClass org.springframework.boot.loader.LaunchedURL ClassLoader --name ROOT --level debug
```
#### View the logger information without appenders
@ -132,46 +117,18 @@ Note that the output will usually be very long.
```bash
[arthas@2062]$ logger --include-no-appender
name ROOT
class ch.qos.logback.classic.Logger
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
level DEBUG
effectiveLevel DEBUG
additivity true
codeSource file:/Users/hengyunabc/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar
appenders name CONSOLE
class ch.qos.logback.core.ConsoleAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
target System.out
name APPLICATION
class ch.qos.logback.core.rolling.RollingFileAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
file app.log
name ASYNC
class ch.qos.logback.classic.AsyncAppender
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
appenderRef [APPLICATION]
name com
class ch.qos.logback.classic.Logger
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
level null
effectiveLevel DEBUG
additivity true
codeSource file:/Users/hengyunabc/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar
name com.alibaba
class ch.qos.logback.classic.Logger
classLoader sun.misc.Launcher$AppClassLoader@2a139a55
classLoaderHash 2a139a55
level null
effectiveLevel DEBUG
additivity true
codeSource file:/Users/hengyunabc/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar
name org.thymeleaf
class ch.qos.logback.classic.Logger
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
level null
effectiveLevel INFO
additivity false
codeSource jar:file:/home/scrapbook/tutorial/demo-arthas-spring-boot.jar!/BOOT-INF/lib/logback-classi
c-1.1.11.jar!/
appenders name DEBUG_LEVEL_REMAPPER
class org.springframework.boot.logging.logback.LevelRemappingAppender
classLoader org.springframework.boot.loader.LaunchedURLClassLoader@5674cd4d
classLoaderHash 5674cd4d
...
```