JVM-SANDBOX简介
JVM-SANDBOX(沙箱)实现了一种在不重启、不侵入目标JVM应用的AOP解决方案。
GIT 地址 https://github.com/alibaba/jvm-sandbox
具有以下特性:
1)无侵入:目标应用无需重启也无需感知沙箱的存在
2)类隔离:沙箱以及沙箱的模块不会和目标应用的类相互干扰
3)可插拔:沙箱以及沙箱的模块可以随时加载和卸载,不会在目标应用留下痕迹
4)多租户:目标应用可以同时挂载不同租户下的沙箱并独立控制
5)高兼容:支持JDK[6,11]
本文将介绍利用 JVM-SANDBOX 自定义修复 exception 的方法。
故障模拟
原服务模拟抛出异常的代码如下:
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@Slf4j
@RestController
public class SandboxController {
@GetMapping("/test/void")
public String testVoid() {
error();
return "success";
}
private void error() {
throw new IllegalStateException("Illegal state!");
}
}
此时,只要请求 /test/void 都会抛出异常。
修复示例
现在,我们提供一个热修复方案:
1. 安装jvm-sandbox。
# 下载
wget https://ompc.oss.aliyuncs.com/jvm-sandbox/release/sandbox-stable-bin.zip
# 解压
unzip sandbox-stable-bin.zip
2. 新建工程,编写修复代码
import com.alibaba.jvm.sandbox.api.Information;
import com.alibaba.jvm.sandbox.api.Module;
import com.alibaba.jvm.sandbox.api.ProcessController;
import com.alibaba.jvm.sandbox.api.annotation.Command;
import com.alibaba.jvm.sandbox.api.listener.ext.Advice;
import com.alibaba.jvm.sandbox.api.listener.ext.AdviceListener;
import com.alibaba.jvm.sandbox.api.listener.ext.EventWatchBuilder;
import com.alibaba.jvm.sandbox.api.resource.ModuleEventWatcher;
import org.kohsuke.MetaInfServices;
import javax.annotation.Resource;
/**
* @author zhengqian
* @date 2023.02.06
*/
@MetaInfServices(Module.class)
@Information(id = "exception-handler")
public class ExceptionHandlerModule implements Module {
@Resource
private ModuleEventWatcher moduleEventWatcher;
@Command("repairExceptionVoid")
public void repairExceptionVoid() {
new EventWatchBuilder(moduleEventWatcher)
.onClass("xxx.xxx.controller.SandboxController") //对应类名
.onBehavior("error") // 对应方法名
.onWatch(new AdviceListener() {
/**
* 拦截指定方法,当这个方法抛出异常时将会被
* AdviceListener#afterThrowing()所拦截
*/
@Override
protected void afterThrowing(Advice advice) throws Throwable {
// 在此,你可以通过ProcessController来改变原有方法的执行流程
// 这里的代码意义是:改变原方法抛出异常的行为,变更为立即返回;void返回值用null表示
ProcessController.returnImmediately(null);
}
});
}
}
工程依赖参考
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>jvm-sandbox-tool</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.deploy.skip>true</maven.deploy.skip>
<maven.install.skip>true</maven.install.skip>
</properties>
<build>
<finalName>${project.name}-${project.version}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
<showDeprecation>true</showDeprecation>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>attached</goal>
</goals>
<phase>package</phase>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>com.alibaba.jvm.sandbox</groupId>
<artifactId>sandbox-module-starter</artifactId>
<version>1.4.0</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>com.alibaba.jvm.sandbox</groupId>
<artifactId>sandbox-api</artifactId>
<version>1.4.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.alibaba.jvm.sandbox</groupId>
<artifactId>sandbox-common-api</artifactId>
<version>1.4.0</version>
</dependency>
<dependency>
<groupId>org.kohsuke.metainf-services</groupId>
<artifactId>metainf-services</artifactId>
<version>1.9</version>
<scope>provided</scope>
</dependency>
<!-- DEBUG工程公共依赖模块,SANDBOX父工程托管 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.4</version>
</dependency>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.2.2</version>
</dependency>
<!-- DEBUG工程独有依赖模块,所以单独配置并指定了版本 -->
<dependency>
<groupId>ognl</groupId>
<artifactId>ognl</artifactId>
<version>3.0.8</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>18.0</version>
</dependency>
<!-- 给DEBUG模块单独配置一个日志 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.24</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.alibaba.fastjson2</groupId>
<artifactId>fastjson2</artifactId>
<version>2.0.23</version>
</dependency>
</dependencies>
</project>
3. 打包,启动
# 打包
mvn clean package
# 将打包好的内容复制到第一步sandbox-module的目录位置,注意改成你自己的目录
cp target/jvm-sandbox-tool-1.0-SNAPSHOT-jar-with-dependencies.jar ~/install/jvm-sandbox/sandbox/sandbox-module/.
4. 启动
# 这里假设 27377 是目标进程号(也就是报异常的原服务)
./sandbox.sh -p 27377
5. 执行修复指令
./sandbox.sh -p 27377 -d 'exception-handler/repairExceptionVoid'
此时再请求 /test/void 会正常返回,不会报错。使用指令 ./sandbox.sh -p 27377 -S
停用sandbox后,服务恢复异常,实现了热插拔。
改为可传参的通用版本
import com.alibaba.fastjson2.JSONObject;
import com.alibaba.jvm.sandbox.api.Information;
import com.alibaba.jvm.sandbox.api.Module;
import com.alibaba.jvm.sandbox.api.ProcessController;
import com.alibaba.jvm.sandbox.api.annotation.Command;
import com.alibaba.jvm.sandbox.api.http.printer.ConcurrentLinkedQueuePrinter;
import com.alibaba.jvm.sandbox.api.http.printer.Printer;
import com.alibaba.jvm.sandbox.api.listener.ext.Advice;
import com.alibaba.jvm.sandbox.api.listener.ext.AdviceListener;
import com.alibaba.jvm.sandbox.api.listener.ext.EventWatchBuilder;
import com.alibaba.jvm.sandbox.api.listener.ext.EventWatcher;
import com.alibaba.jvm.sandbox.api.resource.ModuleEventWatcher;
import org.apache.commons.lang3.StringUtils;
import org.kohsuke.MetaInfServices;
import javax.annotation.Resource;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Map;
@MetaInfServices(Module.class)
@Information(id = "exception-repair", version = "0.0.1", author = "[email protected]")
public class ExceptionRepairModule extends ParamSupported implements Module {
@Resource
private ModuleEventWatcher moduleEventWatcher;
@Command("returnObject")
public void returnObject(final Map<String, String> param, final PrintWriter writer) {
final String cnPattern = getParameter(param, "class");
final String mnPattern = getParameter(param, "method");
final String rtPattern = getParameter(param, "return");
final String rtString = getParameter(param, "returnString");
final Printer printer = new ConcurrentLinkedQueuePrinter(writer);
final EventWatcher watcher = new EventWatchBuilder(moduleEventWatcher)
.onClass(cnPattern)
.onBehavior(mnPattern)
.onWatch(new AdviceListener() {
/**
* 拦截指定方法,当这个方法抛出异常时将会被
* AdviceListener#afterThrowing()所拦截
*/
@Override
protected void afterThrowing(Advice advice) throws Throwable {
Class clazz = Class.forName(rtPattern);
Object object;
if (StringUtils.isEmpty(rtString)) {
object = clazz.newInstance();
printer.print("repair exception, return empty object");
} else {
object = JSONObject.parseObject(rtString, clazz);
printer.print("repair exception, return object: " + object.toString());
}
ProcessController.returnImmediately(object);
}
});
try {
printer.println(String.format(
"tracing on [%s#%s].\nPress CTRL_C abort it!",
cnPattern,
mnPattern
));
printer.waitingForBroken();
} finally {
watcher.onUnWatched();
}
}
@Command("returnEmptyList")
public void returnList(final Map<String, String> param, final PrintWriter writer) {
final String cnPattern = getParameter(param, "class");
final String mnPattern = getParameter(param, "method");
final String rtPattern = getParameter(param, "return");
final Printer printer = new ConcurrentLinkedQueuePrinter(writer);
final EventWatcher watcher = new EventWatchBuilder(moduleEventWatcher)
.onClass(cnPattern)
.onBehavior(mnPattern)
.onWatch(new AdviceListener() {
/**
* 拦截指定方法,当这个方法抛出异常时将会被
* AdviceListener#afterThrowing()所拦截
*/
@Override
protected void afterThrowing(Advice advice) throws Throwable {
ProcessController.returnImmediately(new ArrayList<>());
}
});
try {
printer.println(String.format(
"tracing on [%s#%s].\nPress CTRL_C abort it!",
cnPattern,
mnPattern
));
printer.waitingForBroken();
} finally {
watcher.onUnWatched();
}
}
}
故障模拟
@Slf4j
@RestController
public class SandboxController {
@GetMapping("/test/object")
public SandboxReturnType testObject() {
SandboxReturnType type = errorObject();
log.info("type:{}", type);
return type;
}
private SandboxReturnType errorObject() {
throw new IllegalStateException("Illegal state!");
}
}
@Data
public class SandboxReturnType {
private String name;
}
执行指令,可以指定作用的类、方法、以及需要返回的object(传入的是json字段串,且这里的 returnString 做了urlencode)
./sandbox.sh -p 47620 -d 'exception-repair/returnObject?class=org.example.demo.controller.SandboxController&method=errorObject&return=org.example.demo.controller.SandboxReturnType&returnString=%7B%22name%22%3A%22111%22%7D'
此时,请求 /test/object 时可以正常返回传入的数据,实现热修复
{
"name": 111
}
可传参的通用代码可以打包上传,需要时直接下载使用即可,不需要每次重复写代码、打包处理。
标签:JVM,示例,alibaba,sandbox,api,jvm,import,com From: https://www.cnblogs.com/ylty/p/17108963.html