From 8f3dd1e0e907c9c1723815a7ab3e3b21f691fb56 Mon Sep 17 00:00:00 2001
From: Hollow Man <hollowman186@vip.qq.com>
Date: Fri, 14 Aug 2020 01:00:17 -0500
Subject: [PATCH] add Troubleshoot logger conflicts case scenario #847 (#1338)
---
.../arthas-boot.md | 16 ++++
.../case-logger-config-problem.md | 82 ++++++++++++++++++
.../case-logger-config-problem-cn/finish.md | 10 +++
.../case-logger-config-problem-cn/index.json | 45 ++++++++++
.../case-logger-config-problem-cn/intro.md | 11 +++
.../start-demo.md | 14 ++++
.../arthas-boot.md | 16 ++++
.../case-logger-config-problem.md | 83 +++++++++++++++++++
.../case-logger-config-problem-en/finish.md | 6 ++
.../case-logger-config-problem-en/index.json | 45 ++++++++++
.../case-logger-config-problem-en/intro.md | 11 +++
.../start-demo.md | 14 ++++
12 files changed, 353 insertions(+)
create mode 100644 tutorials/katacoda/case-logger-config-problem-cn/arthas-boot.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-cn/case-logger-config-problem.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-cn/finish.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-cn/index.json
create mode 100644 tutorials/katacoda/case-logger-config-problem-cn/intro.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-cn/start-demo.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-en/arthas-boot.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-en/case-logger-config-problem.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-en/finish.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-en/index.json
create mode 100644 tutorials/katacoda/case-logger-config-problem-en/intro.md
create mode 100644 tutorials/katacoda/case-logger-config-problem-en/start-demo.md
diff --git a/tutorials/katacoda/case-logger-config-problem-cn/arthas-boot.md b/tutorials/katacoda/case-logger-config-problem-cn/arthas-boot.md
new file mode 100644
index 000000000..5c6cb8a17
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-cn/arthas-boot.md
@@ -0,0 +1,16 @@
+
+
+
+
+在新的`Terminal 2`里，下载`arthas-boot.jar`，再用`java -jar`命令启动：
+
+`wget https://arthas.aliyun.com/doc/arthas-boot.jar
+java -jar arthas-boot.jar`{{execute T2}}
+
+`arthas-boot`是`Arthas`的启动程序，它启动后，会列出所有的Java进程，用户可以选择需要诊断的目标进程。
+
+选择第一个进程，输入 `1`{{execute T2}} ，再`Enter/回车`：
+
+Attach成功之后，会打印Arthas LOGO。输入 `help`{{execute T2}} 可以获取到更多的帮助信息。
+
+
diff --git a/tutorials/katacoda/case-logger-config-problem-cn/case-logger-config-problem.md b/tutorials/katacoda/case-logger-config-problem-cn/case-logger-config-problem.md
new file mode 100644
index 000000000..8eea8f1ee
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-cn/case-logger-config-problem.md
@@ -0,0 +1,82 @@
+
+
+在这个案例里，展示排查logger冲突的方法。
+
+### 查找UserController的ClassLoader
+
+`sc -d com.example.demo.arthas.user.UserController | grep classLoaderHash`{{execute T2}}
+
+```bash
+$ sc -d com.example.demo.arthas.user.UserController | grep classLoaderHash
+ classLoaderHash 1be6f5c3
+```
+
+注意hashcode是变化的，需要先查看当前的ClassLoader信息，提取对应ClassLoader的hashcode。
+
+如果你使用`-c`，你需要手动输入hashcode：`-c <hashcode>`
+
+```bash
+$ ognl -c 1be6f5c3 @com.example.demo.arthas.user.UserController@logger
+```
+
+对于只有唯一实例的ClassLoader可以通过`--classLoaderClass`指定class name，使用起来更加方便：
+
+```bash
+$ ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader @org.springframework.boot.SpringApplication@logger
+@Slf4jLocationAwareLog[
+ FQCN=@String[org.apache.commons.logging.LogAdapter$Slf4jLocationAwareLog],
+ name=@String[org.springframework.boot.SpringApplication],
+ logger=@Logger[Logger[org.springframework.boot.SpringApplication]],
+]
+```
+
+`--classLoaderClass` 的值是ClassLoader的类名，只有匹配到唯一的ClassLoader实例时才能工作，目的是方便输入通用命令，而`-c <hashcode>`是动态变化的。
+
+### 确认应用使用的logger系统
+
+以`UserController`为例，它使用的是slf4j api，但实际使用到的logger系统是logback。
+
+`ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '@com.example.demo.arthas.user.UserController@logger'`{{execute T2}}
+
+
+```bash
+$ ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '@com.example.demo.arthas.user.UserController@logger'
+@Logger[
+ serialVersionUID=@Long[5454405123156820674],
+ FQCN=@String[ch.qos.logback.classic.Logger],
+ name=@String[com.example.demo.arthas.user.UserController],
+ level=null,
+ effectiveLevelInt=@Integer[20000],
+ parent=@Logger[Logger[com.example.demo.arthas.user]],
+ childrenList=null,
+ aai=null,
+ additive=@Boolean[true],
+ loggerContext=@LoggerContext[ch.qos.logback.classic.LoggerContext[default]],
+]
+```
+
+### 获取logback实际加载的配置文件
+
+
+`ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '#map1=@org.slf4j.LoggerFactory@getLogger("root").loggerContext.objectMap, #map1.get("CONFIGURATION_WATCH_LIST")'`{{execute T2}}
+
+
+### 使用classloader命令查找可能存在的logger配置文件
+
+`classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r logback-spring.xml`{{execute T2}}
+
+```
+$ classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r logback-spring.xml
+ jar:file:/Users/hengyunabc/code/java/spring-boot-inside/demo-arthas-spring-boot/target/demo-arthas-spring-boot-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/logback-spring.xml
+
+Affect(row-cnt:1) cost in 13 ms.
+```
+可以知道加载的配置的具体来源。
+
+可以尝试加载容易冲突的文件：
+
+`classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r logback.xml`{{execute T2}}
+
+`classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r log4j.properties`{{execute T2}}
+
+
diff --git a/tutorials/katacoda/case-logger-config-problem-cn/finish.md b/tutorials/katacoda/case-logger-config-problem-cn/finish.md
new file mode 100644
index 000000000..e1cc6b0d7
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-cn/finish.md
@@ -0,0 +1,10 @@
+
+通过本教程基本掌握了Arthas排查logger冲突问题。更多高级特性，可以在下面的进阶指南里继续了解。
+
+* [Arthas进阶](https://arthas.aliyun.com/doc/arthas-tutorials?language=cn&id=arthas-advanced)
+* [Arthas Github](https://github.com/alibaba/arthas)
+* [Arthas 文档](https://arthas.aliyun.com/doc/)
+
+欢迎关注公众号，获取Arthas项目的信息，源码分析，案例实践。
+
+
diff --git a/tutorials/katacoda/case-logger-config-problem-cn/index.json b/tutorials/katacoda/case-logger-config-problem-cn/index.json
new file mode 100644
index 000000000..b14f3c41d
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-cn/index.json
@@ -0,0 +1,45 @@
+{
+ "title": "Arthas 排查logger冲突问题 案例",
+ "description": "Arthas 排查logger冲突问题 案例",
+ "difficulty": "高级使用者",
+ "time": "10分钟",
+ "details": {
+ "steps": [
+ {
+ "title": "Start demo",
+ "text": "start-demo.md"
+ },
+ {
+ "title": "Start arthas-boot",
+ "text": "arthas-boot.md"
+ },
+ {
+ "title": "排查logger冲突问题",
+ "text": "case-logger-config-problem.md"
+ }
+ ],
+ "intro": {
+ "text": "intro.md"
+ },
+ "finish": {
+ "text": "finish.md"
+ },
+ "assets": {
+ "host01": []
+ }
+ },
+ "environment": {
+ "uilayout": "terminal",
+ "showdashboard": true,
+ "dashboards": [
+ {
+ "name": "Web Port 80",
+ "port": 80
+ }
+ ]
+ },
+ "backend": {
+ "imageid": "java",
+ "environmentsprotocol": "http"
+ }
+}
\ No newline at end of file
diff --git a/tutorials/katacoda/case-logger-config-problem-cn/intro.md b/tutorials/katacoda/case-logger-config-problem-cn/intro.md
new file mode 100644
index 000000000..305296638
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-cn/intro.md
@@ -0,0 +1,11 @@
+
+
+
+
+
+`Arthas` 是Alibaba开源的Java诊断工具，深受开发者喜爱。在线排查问题，无需重启；动态跟踪Java代码；实时监控JVM状态。
+
+`Arthas` 支持JDK 6+，支持Linux/Mac/Windows，采用命令行交互模式，同时提供丰富的 `Tab` 自动补全功能，进一步方便进行问题的定位和诊断。
+
+* Github: https://github.com/alibaba/arthas
+* 文档: https://arthas.aliyun.com/doc/
\ No newline at end of file
diff --git a/tutorials/katacoda/case-logger-config-problem-cn/start-demo.md b/tutorials/katacoda/case-logger-config-problem-cn/start-demo.md
new file mode 100644
index 000000000..59be66ea6
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-cn/start-demo.md
@@ -0,0 +1,14 @@
+
+
+
+
+下载`demo-arthas-spring-boot.jar`，再用`java -jar`命令启动：
+
+`wget https://github.com/hengyunabc/spring-boot-inside/raw/master/demo-arthas-spring-boot/demo-arthas-spring-boot.jar
+java -jar demo-arthas-spring-boot.jar`{{execute T1}}
+
+`demo-arthas-spring-boot`是一个很简单的spring boot应用，源代码：[查看](https://github.com/hengyunabc/spring-boot-inside/tree/master/demo-arthas-spring-boot)
+
+启动之后，可以访问80端口： https://[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com
+
+
\ No newline at end of file
diff --git a/tutorials/katacoda/case-logger-config-problem-en/arthas-boot.md b/tutorials/katacoda/case-logger-config-problem-en/arthas-boot.md
new file mode 100644
index 000000000..5f6d3f246
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-en/arthas-boot.md
@@ -0,0 +1,16 @@
+
+
+
+
+In the new `Terminal 2`, download `arthas-boot.jar` and start with the `java -jar` command:
+
+`wget https://arthas.aliyun.com/doc/arthas-boot.jar
+java -jar arthas-boot.jar`{{execute T2}}
+
+`arthas-boot` is the launcher for `Arthas`. It lists all the Java processes, and the user can select the target process to be diagnosed.
+
+Select the first process, type `1`{{execute T2}} ，then type `Enter`：
+
+After the Attach is successful, Arthas LOGO is printed. Enter `help`{{execute T2}} for more help.
+
+
diff --git a/tutorials/katacoda/case-logger-config-problem-en/case-logger-config-problem.md b/tutorials/katacoda/case-logger-config-problem-en/case-logger-config-problem.md
new file mode 100644
index 000000000..49a6d5083
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-en/case-logger-config-problem.md
@@ -0,0 +1,83 @@
+
+
+
+In this case, show how to troubleshoot logger conflicts.
+
+### Find the ClassLoader of the UserController
+
+`sc -d com.example.demo.arthas.user.UserController | grep classLoaderHash`{{execute T2}}
+
+```bash
+$ sc -d com.example.demo.arthas.user.UserController | grep classLoaderHash
+ classLoaderHash 1be6f5c3
+```
+
+Please write down your classLoaderHash here since it's dynamic. In the case here, it's `1be6f5c3`.
+
+if you use`-c`, you have to manually type hashcode by `-c <hashcode>`.
+
+```bash
+$ ognl -c 1be6f5c3 @com.example.demo.arthas.user.UserController@logger
+```
+
+For classloader with only one instance, it can be specified by `--classLoaderClass` using class name, which is more convenient to use.
+
+```bash
+$ ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader @org.springframework.boot.SpringApplication@logger
+@Slf4jLocationAwareLog[
+ FQCN=@String[org.apache.commons.logging.LogAdapter$Slf4jLocationAwareLog],
+ name=@String[org.springframework.boot.SpringApplication],
+ logger=@Logger[Logger[org.springframework.boot.SpringApplication]],
+]
+```
+
+The value of `--classloaderclass` is the class name of classloader. It can only work when it matches a unique classloader instance. The purpose is to facilitate the input of general commands. However, `-c <hashcode>` is dynamic.
+
+### View the logger system used by the app
+
+Take `UserController` as an example, it uses slf4j api, but the actual logger system used is logback.
+
+`ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '@com.example.demo.arthas.user.UserController@logger'`{{execute T2}}
+
+
+```bash
+$ ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '@com.example.demo.arthas.user.UserController@logger'
+@Logger[
+ serialVersionUID=@Long[5454405123156820674],
+ FQCN=@String[ch.qos.logback.classic.Logger],
+ name=@String[com.example.demo.arthas.user.UserController],
+ level=null,
+ effectiveLevelInt=@Integer[20000],
+ parent=@Logger[Logger[com.example.demo.arthas.user]],
+ childrenList=null,
+ aai=null,
+ additive=@Boolean[true],
+ loggerContext=@LoggerContext[ch.qos.logback.classic.LoggerContext[default]],
+]
+```
+
+### Find the configuration file actually loaded by the logback
+
+
+`ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '#map1=@org.slf4j.LoggerFactory@getLogger("root").loggerContext.objectMap, #map1.get("CONFIGURATION_WATCH_LIST")'`{{execute T2}}
+
+
+### Use the classloader command to find possible logger configuration files
+
+`classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r logback-spring.xml`{{execute T2}}
+
+```
+$ classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r logback-spring.xml
+ jar:file:/Users/hengyunabc/code/java/spring-boot-inside/demo-arthas-spring-boot/target/demo-arthas-spring-boot-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/logback-spring.xml
+
+Affect(row-cnt:1) cost in 13 ms.
+```
+You can know the specific source of the loaded configuration.
+
+You can try to load files that are prone to conflict:
+
+`classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r logback.xml`{{execute T2}}
+
+`classloader --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader -r log4j.properties`{{execute T2}}
+
+
diff --git a/tutorials/katacoda/case-logger-config-problem-en/finish.md b/tutorials/katacoda/case-logger-config-problem-en/finish.md
new file mode 100644
index 000000000..3fa721e63
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-en/finish.md
@@ -0,0 +1,6 @@
+
+Through this tutorial, you can know how to Troubleshoot logger conflicts. More advanced features can be found in the Advanced Guide below.
+
+* [Arthas Advanced](https://arthas.aliyun.com/doc/arthas-tutorials?language=en&id=arthas-advanced)
+* [Arthas Github](https://github.com/alibaba/arthas)
+* [Arthas Documentation](https://arthas.aliyun.com/doc/en)
diff --git a/tutorials/katacoda/case-logger-config-problem-en/index.json b/tutorials/katacoda/case-logger-config-problem-en/index.json
new file mode 100644
index 000000000..0cd78b0fd
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-en/index.json
@@ -0,0 +1,45 @@
+{
+ "title": "Arthas Troubleshoot logger conflicts",
+ "description": "Arthas Troubleshoot logger conflicts",
+ "difficulty": "expert",
+ "time": "10 minutes",
+ "details": {
+ "steps": [
+ {
+ "title": "Start demo",
+ "text": "start-demo.md"
+ },
+ {
+ "title": "Start arthas-boot",
+ "text": "arthas-boot.md"
+ },
+ {
+ "title": "Troubleshoot logger conflicts",
+ "text": "case-logger-config-problem.md"
+ }
+ ],
+ "intro": {
+ "text": "intro.md"
+ },
+ "finish": {
+ "text": "finish.md"
+ },
+ "assets": {
+ "host01": []
+ }
+ },
+ "environment": {
+ "uilayout": "terminal",
+ "showdashboard": true,
+ "dashboards": [
+ {
+ "name": "Web Port 80",
+ "port": 80
+ }
+ ]
+ },
+ "backend": {
+ "imageid": "java",
+ "environmentsprotocol": "http"
+ }
+}
\ No newline at end of file
diff --git a/tutorials/katacoda/case-logger-config-problem-en/intro.md b/tutorials/katacoda/case-logger-config-problem-en/intro.md
new file mode 100644
index 000000000..c27afd332
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-en/intro.md
@@ -0,0 +1,11 @@
+
+
+
+
+
+`Arthas` is a Java diagnostic tool open-sourced by Alibaba middleware team. Arthas helps developers in trouble-shooting issues in production environment for Java based applications without modifying code or restarting servers.
+
+`Arthas` supports JDK 6+, supports Linux/Mac/Windows.
+
+* Github: https://github.com/alibaba/arthas
+* Documentation: https://arthas.aliyun.com/doc/en
\ No newline at end of file
diff --git a/tutorials/katacoda/case-logger-config-problem-en/start-demo.md b/tutorials/katacoda/case-logger-config-problem-en/start-demo.md
new file mode 100644
index 000000000..4915b847a
--- /dev/null
+++ b/tutorials/katacoda/case-logger-config-problem-en/start-demo.md
@@ -0,0 +1,14 @@
+
+
+
+
+Download `demo-arthas-spring-boot.jar`, and start with `java -jar` command:
+
+`wget https://github.com/hengyunabc/spring-boot-inside/raw/master/demo-arthas-spring-boot/demo-arthas-spring-boot.jar
+java -jar demo-arthas-spring-boot.jar`{{execute T1}}
+
+`demo-arthas-spring-boot` is a simple Spring Boot demo, the source code here: [View](https://github.com/hengyunabc/spring-boot-inside/tree/master/demo-arthas-spring-boot)
+
+After booting, access port 80: https://[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com
+
+
\ No newline at end of file