「这是我参与2022首次更文挑战的第29天，活动详情查看：2022首次更文挑战」。
xxl-job 在当下是一个炙手可热的分布式任务调度框架，在分布式系统中我们常常通过xxl-job做定时任务，它简单易用，天然支持分布式场景，多种路由策略可选，支持弹性扩缩容...本篇文章我们就从源码层面分析一下xxl-job-core（执行器）。
1 xxl-job 简介
XXL-JOB是一个分布式任务调度平台，其核心设计目标是开发迅速、学习简单、轻量级、易扩展。
其源码分为三部分：
- xxl-job-admin 调度中心
- xxl-job-core 核心依赖
- xxl-job-executor-samples 示例
2 xxl-job-core
本篇文章我们先来分析一下xxl-job-core包下的内容。
2.1 XxlJobExecutor
首先core中最核心的部分是xxl-job的执行器XxlJobExecutor，它的启动方式是在其子类中实现的，我们先看其子类。
其具有两大子类，分别适用于不同场景的集成
-
XxlJobSimpleExecutor（简单） 需要将任务对象传入执行器，从而获取任务，这里我们不做重点讲解
-
XxlJobSpringExecutor（Spring）与Spring框架集成，容器初始化之后，通过Spring上下文扫描自动获取任务，并启动执行器
public class XxlJobSpringExecutor extends XxlJobExecutor implements ApplicationContextAware, SmartInitializingSingleton, DisposableBean { private static final Logger logger = LoggerFactory.getLogger(XxlJobSpringExecutor.class); // 启动执行器 @Override public void afterSingletonsInstantiated() { // 初始化任务处理器 initJobHandlerMethodRepository(applicationContext); // new SpringGlueFactory(); GlueFactory.refreshInstance(1); try { // 调用父类的启动 super.start(); } catch (Exception e) { throw new RuntimeException(e); } } @Override public void destroy() { super.destroy(); } private void initJobHandlerMethodRepository(ApplicationContext applicationContext) { if (applicationContext == null) { return; } // init job handler from method String[] beanDefinitionNames = applicationContext.getBeanNamesForType(Object.class, false, true); for (String beanDefinitionName : beanDefinitionNames) { Object bean = applicationContext.getBean(beanDefinitionName); Map<Method, XxlJob> annotatedMethods = null; try { annotatedMethods = MethodIntrospector.selectMethods(bean.getClass(), new MethodIntrospector.MetadataLookup<XxlJob>() { @Override public XxlJob inspect(Method method) { return AnnotatedElementUtils.findMergedAnnotation(method, XxlJob.class); } }); } catch (Throwable ex) { logger.error("xxl-job method-jobhandler resolve error for bean[" + beanDefinitionName + "].", ex); } if (annotatedMethods==null || annotatedMethods.isEmpty()) { continue; } for (Map.Entry<Method, XxlJob> methodXxlJobEntry : annotatedMethods.entrySet()) { Method executeMethod = methodXxlJobEntry.getKey(); XxlJob xxlJob = methodXxlJobEntry.getValue(); if (xxlJob == null) { continue; } String name = xxlJob.value(); if (name.trim().length() == 0) { throw new RuntimeException("xxl-job method-jobhandler name invalid, for[" + bean.getClass() + "#" + executeMethod.getName() + "] ."); } if (loadJobHandler(name) != null) { throw new RuntimeException("xxl-job jobhandler[" + name + "] naming conflicts."); } executeMethod.setAccessible(true); // init and destory Method initMethod = null; Method destroyMethod = null; if (xxlJob.init().trim().length() > 0) { try { initMethod = bean.getClass().getDeclaredMethod(xxlJob.init()); initMethod.setAccessible(true); } catch (NoSuchMethodException e) { throw new RuntimeException("xxl-job method-jobhandler initMethod invalid, for[" + bean.getClass() + "#" + executeMethod.getName() + "] ."); } } if (xxlJob.destroy().trim().length() > 0) { try { destroyMethod = bean.getClass().getDeclaredMethod(xxlJob.destroy()); destroyMethod.setAccessible(true); } catch (NoSuchMethodException e) { throw new RuntimeException("xxl-job method-jobhandler destroyMethod invalid, for[" + bean.getClass() + "#" + executeMethod.getName() + "] ."); } } // registry jobhandler registJobHandler(name, new MethodJobHandler(bean, executeMethod, initMethod, destroyMethod)); } } } // ---------------------- applicationContext ---------------------- private static ApplicationContext applicationContext; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.applicationContext = applicationContext; } public static ApplicationContext getApplicationContext() { return applicationContext; } }
我们再来看执行器XxlJobExecutor中的功能
-
启动 start()
-
初始化日志
-
初始化rpc调用方列表，根据admin地址和token初始化一个调用列表（admin地址和token通过配置文件获取）
-
初始化任务日志文件清理
这里会调用JobLogFileCleanThread线程- - ，每天调用一次文件清理
-
初始化任务触发器回调TriggerCallbackThread（反馈调度结果）
-
初始化rpc提供方，将address, ip, port, appname, accessToken设置到执行服务中
-
启动rpc嵌入服务embedServer.start(address, port, appname, accessToken);
这里通过Nettyn内嵌http服务，启动服务后，会启动额外线程（ExecutorRegistryThread）注册appname, address
以下为服务注册线程，服务注册线程会调用之前创建好的rpc调用方列表AdminBizList，executor执行器通过远程调用的方式向admin调度中注册的心跳线程registryThread:
public class ExecutorRegistryThread { private static Logger logger = LoggerFactory.getLogger(ExecutorRegistryThread.class); private static ExecutorRegistryThread instance = new ExecutorRegistryThread(); public static ExecutorRegistryThread getInstance(){ return instance; } private Thread registryThread; private volatile boolean toStop = false; public void start(final String appname, final String address){ // valid if (appname==null || appname.trim().length()==0) { logger.warn(">>>>>>>>>>> xxl-job, executor registry config fail, appname is null."); return; } if (XxlJobExecutor.getAdminBizList() == null) { logger.warn(">>>>>>>>>>> xxl-job, executor registry config fail, adminAddresses is null."); return; } registryThread = new Thread(new Runnable() { @Override public void run() { // registry while (!toStop) { try { RegistryParam registryParam = new RegistryParam(RegistryConfig.RegistType.EXECUTOR.name(), appname, address); for (AdminBiz adminBiz: XxlJobExecutor.getAdminBizList()) { try { ReturnT<String> registryResult = adminBiz.registry(registryParam); if (registryResult!=null && ReturnT.SUCCESS_CODE == registryResult.getCode()) { registryResult = ReturnT.SUCCESS; logger.debug(">>>>>>>>>>> xxl-job registry success, registryParam:{}, registryResult:{}", new Object[]{registryParam, registryResult}); break; } else { logger.info(">>>>>>>>>>> xxl-job registry fail, registryParam:{}, registryResult:{}", new Object[]{registryParam, registryResult}); } } catch (Exception e) { logger.info(">>>>>>>>>>> xxl-job registry error, registryParam:{}", registryParam, e); } } } catch (Exception e) { if (!toStop) { logger.error(e.getMessage(), e); } } try { if (!toStop) { TimeUnit.SECONDS.sleep(RegistryConfig.BEAT_TIMEOUT); } } catch (InterruptedException e) { if (!toStop) { logger.warn(">>>>>>>>>>> xxl-job, executor registry thread interrupted, error msg:{}", e.getMessage()); } } } // registry remove try { RegistryParam registryParam = new RegistryParam(RegistryConfig.RegistType.EXECUTOR.name(), appname, address); for (AdminBiz adminBiz: XxlJobExecutor.getAdminBizList()) { try { ReturnT<String> registryResult = adminBiz.registryRemove(registryParam); if (registryResult!=null && ReturnT.SUCCESS_CODE == registryResult.getCode()) { registryResult = ReturnT.SUCCESS; logger.info(">>>>>>>>>>> xxl-job registry-remove success, registryParam:{}, registryResult:{}", new Object[]{registryParam, registryResult}); break; } else { logger.info(">>>>>>>>>>> xxl-job registry-remove fail, registryParam:{}, registryResult:{}", new Object[]{registryParam, registryResult}); } } catch (Exception e) { if (!toStop) { logger.info(">>>>>>>>>>> xxl-job registry-remove error, registryParam:{}", registryParam, e); } } } } catch (Exception e) { if (!toStop) { logger.error(e.getMessage(), e); } } logger.info(">>>>>>>>>>> xxl-job, executor registry thread destroy."); } }); registryThread.setDaemon(true); registryThread.setName("xxl-job, executor ExecutorRegistryThread"); registryThread.start(); } public void toStop() { toStop = true; // interrupt and wait if (registryThread != null) { registryThread.interrupt(); try { registryThread.join(); } catch (InterruptedException e) { logger.error(e.getMessage(), e); } } } }
-
-
-
销毁 destroy
-
rpc的调用方 initAdminBizList（在启动时调用）
-
rpc的提供方 initEmbedServer（在启动时调用）
-
注册销毁任务处理器（Spring容器初始化之后，扫描到标记注解的方法后，- 调用注册任务处理器，在执行器初始化之前调用）
-
注册销毁任务线程（执行器被调用时会启动执行任务）
涵盖了执行器的启动，销毁方法
public class XxlJobExecutor {
private static final Logger logger = LoggerFactory.getLogger(XxlJobExecutor.class);
// ---------------------- param ----------------------
private String adminAddresses;
private String accessToken;
private String appname;
private String address;
private String ip;
private int port;
private String logPath;
private int logRetentionDays;
public void setAdminAddresses(String adminAddresses) {
this.adminAddresses = adminAddresses;
}
public void setAccessToken(String accessToken) {
this.accessToken = accessToken;
}
public void setAppname(String appname) {
this.appname = appname;
}
public void setAddress(String address) {
this.address = address;
}
public void setIp(String ip) {
this.ip = ip;
}
public void setPort(int port) {
this.port = port;
}
public void setLogPath(String logPath) {
this.logPath = logPath;
}
public void setLogRetentionDays(int logRetentionDays) {
this.logRetentionDays = logRetentionDays;
}
// ---------------------- start + stop ----------------------
public void start() throws Exception {
// 初始化日志
XxlJobFileAppender.initLogPath(logPath);
// 初始化rpc调用方，根据admin地址和token初始化一个调用列表（admin地址和token通过配置文件获取）
initAdminBizList(adminAddresses, accessToken);
// 初始化任务日志文件清理
JobLogFileCleanThread.getInstance().start(logRetentionDays);
// 初始化任务触发器回调TriggerCallbackThread
TriggerCallbackThread.getInstance().start();
// init executor-server
initEmbedServer(address, ip, port, appname, accessToken);
}
public void destroy(){
// destory executor-server
stopEmbedServer();
// destory jobThreadRepository
if (jobThreadRepository.size() > 0) {
for (Map.Entry<Integer, JobThread> item: jobThreadRepository.entrySet()) {
JobThread oldJobThread = removeJobThread(item.getKey(), "web container destroy and kill the job.");
// wait for job thread push result to callback queue
if (oldJobThread != null) {
try {
oldJobThread.join();
} catch (InterruptedException e) {
logger.error(">>>>>>>>>>> xxl-job, JobThread destroy(join) error, jobId:{}", item.getKey(), e);
}
}
}
jobThreadRepository.clear();
}
jobHandlerRepository.clear();
// destory JobLogFileCleanThread
JobLogFileCleanThread.getInstance().toStop();
// destory TriggerCallbackThread
TriggerCallbackThread.getInstance().toStop();
}
// ---------------------- admin-client (rpc invoker) ----------------------
private static List<AdminBiz> adminBizList;
private void initAdminBizList(String adminAddresses, String accessToken) throws Exception {
if (adminAddresses!=null && adminAddresses.trim().length()>0) {
for (String address: adminAddresses.trim().split(",")) {
if (address!=null && address.trim().length()>0) {
AdminBiz adminBiz = new AdminBizClient(address.trim(), accessToken);
if (adminBizList == null) {
adminBizList = new ArrayList<AdminBiz>();
}
adminBizList.add(adminBiz);
}
}
}
}
public static List<AdminBiz> getAdminBizList(){
return adminBizList;
}
// ---------------------- executor-server (rpc provider) ----------------------
private EmbedServer embedServer = null;
private void initEmbedServer(String address, String ip, int port, String appname, String accessToken) throws Exception {
// fill ip port
port = port>0?port: NetUtil.findAvailablePort(9999);
ip = (ip!=null&&ip.trim().length()>0)?ip: IpUtil.getIp();
// generate address
if (address==null || address.trim().length()==0) {
String ip_port_address = IpUtil.getIpPort(ip, port); // registry-address：default use address to registry , otherwise use ip:port if address is null
address = "http://{ip_port}/".replace("{ip_port}", ip_port_address);
}
// accessToken
if (accessToken==null || accessToken.trim().length()==0) {
logger.warn(">>>>>>>>>>> xxl-job accessToken is empty. To ensure system security, please set the accessToken.");
}
// start
embedServer = new EmbedServer();
embedServer.start(address, port, appname, accessToken);
}
private void stopEmbedServer() {
// stop provider factory
if (embedServer != null) {
try {
embedServer.stop();
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
}
// ---------------------- job handler repository ----------------------
private static ConcurrentMap<String, IJobHandler> jobHandlerRepository = new ConcurrentHashMap<String, IJobHandler>();
public static IJobHandler loadJobHandler(String name){
return jobHandlerRepository.get(name);
}
public static IJobHandler registJobHandler(String name, IJobHandler jobHandler){
logger.info(">>>>>>>>>>> xxl-job register jobhandler success, name:{}, jobHandler:{}", name, jobHandler);
return jobHandlerRepository.put(name, jobHandler);
}
// ---------------------- job thread repository ----------------------
private static ConcurrentMap<Integer, JobThread> jobThreadRepository = new ConcurrentHashMap<Integer, JobThread>();
public static JobThread registJobThread(int jobId, IJobHandler handler, String removeOldReason){
JobThread newJobThread = new JobThread(jobId, handler);
newJobThread.start();
logger.info(">>>>>>>>>>> xxl-job regist JobThread success, jobId:{}, handler:{}", new Object[]{jobId, handler});
JobThread oldJobThread = jobThreadRepository.put(jobId, newJobThread); // putIfAbsent | oh my god, map's put method return the old value!!!
if (oldJobThread != null) {
oldJobThread.toStop(removeOldReason);
oldJobThread.interrupt();
}
return newJobThread;
}
public static JobThread removeJobThread(int jobId, String removeOldReason){
JobThread oldJobThread = jobThreadRepository.remove(jobId);
if (oldJobThread != null) {
oldJobThread.toStop(removeOldReason);
oldJobThread.interrupt();
return oldJobThread;
}
return null;
}
public static JobThread loadJobThread(int jobId){
JobThread jobThread = jobThreadRepository.get(jobId);
return jobThread;
}
}
2.2 EmbedServer
通过Netty构建Http内嵌服务，这里也是admin和执行器进行rpc通信的核心，也是Netty的经典应用场景
public class EmbedServer {
private static final Logger logger = LoggerFactory.getLogger(EmbedServer.class);
private ExecutorBiz executorBiz;
private Thread thread;
public void start(final String address, final int port, final String appname, final String accessToken) {
executorBiz = new ExecutorBizImpl();
thread = new Thread(new Runnable() {
@Override
public void run() {
// param
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
ThreadPoolExecutor bizThreadPool = new ThreadPoolExecutor(
0,
200,
60L,
TimeUnit.SECONDS,
new LinkedBlockingQueue<Runnable>(2000),
new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
return new Thread(r, "xxl-job, EmbedServer bizThreadPool-" + r.hashCode());
}
},
new RejectedExecutionHandler() {
@Override
public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
throw new RuntimeException("xxl-job, EmbedServer bizThreadPool is EXHAUSTED!");
}
});
try {
// start server
ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel channel) throws Exception {
channel.pipeline()
.addLast(new IdleStateHandler(0, 0, 30 * 3, TimeUnit.SECONDS))
.addLast(new HttpServerCodec())
.addLast(new HttpObjectAggregator(5 * 1024 * 1024))
.addLast(new EmbedHttpServerHandler(executorBiz, accessToken, bizThreadPool));
}
})
.childOption(ChannelOption.SO_KEEPALIVE, true);
// bind
ChannelFuture future = bootstrap.bind(port).sync();
logger.info(">>>>>>>>>>> xxl-job remoting server start success, nettype = {}, port = {}", EmbedServer.class, port);
// start registry
startRegistry(appname, address);
// wait util stop
future.channel().closeFuture().sync();
} catch (InterruptedException e) {
if (e instanceof InterruptedException) {
logger.info(">>>>>>>>>>> xxl-job remoting server stop.");
} else {
logger.error(">>>>>>>>>>> xxl-job remoting server error.", e);
}
} finally {
// stop
try {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
}
});
thread.setDaemon(true);
thread.start();
}
public void stop() throws Exception {
// destroy server thread
if (thread!=null && thread.isAlive()) {
thread.interrupt();
}
// stop registry
stopRegistry();
logger.info(">>>>>>>>>>> xxl-job remoting server destroy success.");
}
// ---------------------- registry ----------------------
/**
* netty_http
*/
public static class EmbedHttpServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
private static final Logger logger = LoggerFactory.getLogger(EmbedHttpServerHandler.class);
private ExecutorBiz executorBiz;
private String accessToken;
private ThreadPoolExecutor bizThreadPool;
public EmbedHttpServerHandler(ExecutorBiz executorBiz, String accessToken, ThreadPoolExecutor bizThreadPool) {
this.executorBiz = executorBiz;
this.accessToken = accessToken;
this.bizThreadPool = bizThreadPool;
}
@Override
protected void channelRead0(final ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
// request parse
//final byte[] requestBytes = ByteBufUtil.getBytes(msg.content()); // byteBuf.toString(io.netty.util.CharsetUtil.UTF_8);
String requestData = msg.content().toString(CharsetUtil.UTF_8);
String uri = msg.uri();
HttpMethod httpMethod = msg.method();
boolean keepAlive = HttpUtil.isKeepAlive(msg);
String accessTokenReq = msg.headers().get(XxlJobRemotingUtil.XXL_JOB_ACCESS_TOKEN);
// invoke
bizThreadPool.execute(new Runnable() {
@Override
public void run() {
// do invoke
Object responseObj = process(httpMethod, uri, requestData, accessTokenReq);
// to json
String responseJson = GsonTool.toJson(responseObj);
// write response
writeResponse(ctx, keepAlive, responseJson);
}
});
}
private Object process(HttpMethod httpMethod, String uri, String requestData, String accessTokenReq) {
// valid
if (HttpMethod.POST != httpMethod) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "invalid request, HttpMethod not support.");
}
if (uri==null || uri.trim().length()==0) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "invalid request, uri-mapping empty.");
}
if (accessToken!=null
&& accessToken.trim().length()>0
&& !accessToken.equals(accessTokenReq)) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "The access token is wrong.");
}
// services mapping
try {
if ("/beat".equals(uri)) {
return executorBiz.beat();
} else if ("/idleBeat".equals(uri)) {
IdleBeatParam idleBeatParam = GsonTool.fromJson(requestData, IdleBeatParam.class);
return executorBiz.idleBeat(idleBeatParam);
} else if ("/run".equals(uri)) {
TriggerParam triggerParam = GsonTool.fromJson(requestData, TriggerParam.class);
return executorBiz.run(triggerParam);
} else if ("/kill".equals(uri)) {
KillParam killParam = GsonTool.fromJson(requestData, KillParam.class);
return executorBiz.kill(killParam);
} else if ("/log".equals(uri)) {
LogParam logParam = GsonTool.fromJson(requestData, LogParam.class);
return executorBiz.log(logParam);
} else {
return new ReturnT<String>(ReturnT.FAIL_CODE, "invalid request, uri-mapping("+ uri +") not found.");
}
} catch (Exception e) {
logger.error(e.getMessage(), e);
return new ReturnT<String>(ReturnT.FAIL_CODE, "request error:" + ThrowableUtil.toString(e));
}
}
/**
* write response
*/
private void writeResponse(ChannelHandlerContext ctx, boolean keepAlive, String responseJson) {
// write response
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, Unpooled.copiedBuffer(responseJson, CharsetUtil.UTF_8)); // Unpooled.wrappedBuffer(responseJson)
response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/html;charset=UTF-8"); // HttpHeaderValues.TEXT_PLAIN.toString()
response.headers().set(HttpHeaderNames.CONTENT_LENGTH, response.content().readableBytes());
if (keepAlive) {
response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
}
ctx.writeAndFlush(response);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
logger.error(">>>>>>>>>>> xxl-job provider netty_http server caught exception", cause);
ctx.close();
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
if (evt instanceof IdleStateEvent) {
ctx.channel().close(); // beat 3N, close if idle
logger.debug(">>>>>>>>>>> xxl-job provider netty_http server close an idle channel.");
} else {
super.userEventTriggered(ctx, evt);
}
}
}
// ---------------------- registry ----------------------
public void startRegistry(final String appname, final String address) {
ExecutorRegistryThread.getInstance().start(appname, address);
}
public void stopRegistry() {
ExecutorRegistryThread.getInstance().toStop();
}
}
2.3 ExecutorBizImpl
用于执行admin调度中心发送过来的执行请求，EmbedServer 收到来自调度中心的run请求时会启动该类中的run方法。然后加载任务线程，通过对应的处理器，注册任务
public class ExecutorBizImpl implements ExecutorBiz {
private static Logger logger = LoggerFactory.getLogger(ExecutorBizImpl.class);
@Override
public ReturnT<String> beat() {
return ReturnT.SUCCESS;
}
@Override
public ReturnT<String> idleBeat(IdleBeatParam idleBeatParam) {
// isRunningOrHasQueue
boolean isRunningOrHasQueue = false;
JobThread jobThread = XxlJobExecutor.loadJobThread(idleBeatParam.getJobId());
if (jobThread != null && jobThread.isRunningOrHasQueue()) {
isRunningOrHasQueue = true;
}
if (isRunningOrHasQueue) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "job thread is running or has trigger queue.");
}
return ReturnT.SUCCESS;
}
@Override
public ReturnT<String> run(TriggerParam triggerParam) {
// load old：jobHandler + jobThread
JobThread jobThread = XxlJobExecutor.loadJobThread(triggerParam.getJobId());
IJobHandler jobHandler = jobThread!=null?jobThread.getHandler():null;
String removeOldReason = null;
// valid：jobHandler + jobThread
GlueTypeEnum glueTypeEnum = GlueTypeEnum.match(triggerParam.getGlueType());
if (GlueTypeEnum.BEAN == glueTypeEnum) {
// new jobhandler
IJobHandler newJobHandler = XxlJobExecutor.loadJobHandler(triggerParam.getExecutorHandler());
// valid old jobThread
if (jobThread!=null && jobHandler != newJobHandler) {
// change handler, need kill old thread
removeOldReason = "change jobhandler or glue type, and terminate the old job thread.";
jobThread = null;
jobHandler = null;
}
// valid handler
if (jobHandler == null) {
jobHandler = newJobHandler;
if (jobHandler == null) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "job handler [" + triggerParam.getExecutorHandler() + "] not found.");
}
}
} else if (GlueTypeEnum.GLUE_GROOVY == glueTypeEnum) {
if (jobThread != null &&
!(jobThread.getHandler() instanceof GlueJobHandler
&& ((GlueJobHandler) jobThread.getHandler()).getGlueUpdatetime()==triggerParam.getGlueUpdatetime() )) {
// change handler or gluesource updated, need kill old thread
removeOldReason = "change job source or glue type, and terminate the old job thread.";
jobThread = null;
jobHandler = null;
}
if (jobHandler == null) {
try {
IJobHandler originJobHandler = GlueFactory.getInstance().loadNewInstance(triggerParam.getGlueSource());
jobHandler = new GlueJobHandler(originJobHandler, triggerParam.getGlueUpdatetime());
} catch (Exception e) {
logger.error(e.getMessage(), e);
return new ReturnT<String>(ReturnT.FAIL_CODE, e.getMessage());
}
}
} else if (glueTypeEnum!=null && glueTypeEnum.isScript()) {
if (jobThread != null &&
!(jobThread.getHandler() instanceof ScriptJobHandler
&& ((ScriptJobHandler) jobThread.getHandler()).getGlueUpdatetime()==triggerParam.getGlueUpdatetime() )) {
// change script or gluesource updated, need kill old thread
removeOldReason = "change job source or glue type, and terminate the old job thread.";
jobThread = null;
jobHandler = null;
}
// valid handler
if (jobHandler == null) {
jobHandler = new ScriptJobHandler(triggerParam.getJobId(), triggerParam.getGlueUpdatetime(), triggerParam.getGlueSource(), GlueTypeEnum.match(triggerParam.getGlueType()));
}
} else {
return new ReturnT<String>(ReturnT.FAIL_CODE, "glueType[" + triggerParam.getGlueType() + "] is not valid.");
}
// executor block strategy
if (jobThread != null) {
ExecutorBlockStrategyEnum blockStrategy = ExecutorBlockStrategyEnum.match(triggerParam.getExecutorBlockStrategy(), null);
if (ExecutorBlockStrategyEnum.DISCARD_LATER == blockStrategy) {
// discard when running
if (jobThread.isRunningOrHasQueue()) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "block strategy effect："+ExecutorBlockStrategyEnum.DISCARD_LATER.getTitle());
}
} else if (ExecutorBlockStrategyEnum.COVER_EARLY == blockStrategy) {
// kill running jobThread
if (jobThread.isRunningOrHasQueue()) {
removeOldReason = "block strategy effect：" + ExecutorBlockStrategyEnum.COVER_EARLY.getTitle();
jobThread = null;
}
} else {
// just queue trigger
}
}
// replace thread (new or exists invalid)
if (jobThread == null) {
jobThread = XxlJobExecutor.registJobThread(triggerParam.getJobId(), jobHandler, removeOldReason);
}
// push data to queue
ReturnT<String> pushResult = jobThread.pushTriggerQueue(triggerParam);
return pushResult;
}
@Override
public ReturnT<String> kill(KillParam killParam) {
// kill handlerThread, and create new one
JobThread jobThread = XxlJobExecutor.loadJobThread(killParam.getJobId());
if (jobThread != null) {
XxlJobExecutor.removeJobThread(killParam.getJobId(), "scheduling center kill job.");
return ReturnT.SUCCESS;
}
return new ReturnT<String>(ReturnT.SUCCESS_CODE, "job thread already killed.");
}
@Override
public ReturnT<LogResult> log(LogParam logParam) {
// log filename: logPath/yyyy-MM-dd/9999.log
String logFileName = XxlJobFileAppender.makeLogFileName(new Date(logParam.getLogDateTim()), logParam.getLogId());
LogResult logResult = XxlJobFileAppender.readLog(logFileName, logParam.getFromLineNum());
return new ReturnT<LogResult>(logResult);
}
}
2.4 JobThread
任务线程，通过任务线程执行对应的任务处理
步骤：
-
初始化处理器
-
执行
- 取出队列triggerQueue
- 移除triggerLogIdSet记录
- 设置XxlJobContext内容
- 执行处理器
- 获取执行结果
- 删除任务线程
-
调用TriggerCallbackThread反馈调度结果
-
销毁处理器
public class JobThread extends Thread{
private static Logger logger = LoggerFactory.getLogger(JobThread.class);
private int jobId;
private IJobHandler handler;
private LinkedBlockingQueue<TriggerParam> triggerQueue;
private Set<Long> triggerLogIdSet; // avoid repeat trigger for the same TRIGGER_LOG_ID
private volatile boolean toStop = false;
private String stopReason;
private boolean running = false; // if running job
private int idleTimes = 0; // idel times
public JobThread(int jobId, IJobHandler handler) {
this.jobId = jobId;
this.handler = handler;
this.triggerQueue = new LinkedBlockingQueue<TriggerParam>();
this.triggerLogIdSet = Collections.synchronizedSet(new HashSet<Long>());
// assign job thread name
this.setName("xxl-job, JobThread-"+jobId+"-"+System.currentTimeMillis());
}
public IJobHandler getHandler() {
return handler;
}
/**
* new trigger to queue
*
* @param triggerParam
* @return
*/
public ReturnT<String> pushTriggerQueue(TriggerParam triggerParam) {
// avoid repeat
if (triggerLogIdSet.contains(triggerParam.getLogId())) {
logger.info(">>>>>>>>>>> repeate trigger job, logId:{}", triggerParam.getLogId());
return new ReturnT<String>(ReturnT.FAIL_CODE, "repeate trigger job, logId:" + triggerParam.getLogId());
}
triggerLogIdSet.add(triggerParam.getLogId());
triggerQueue.add(triggerParam);
return ReturnT.SUCCESS;
}
/**
* kill job thread
*
* @param stopReason
*/
public void toStop(String stopReason) {
/**
* Thread.interrupt只支持终止线程的阻塞状态(wait、join、sleep)，
* 在阻塞出抛出InterruptedException异常,但是并不会终止运行的线程本身；
* 所以需要注意，此处彻底销毁本线程，需要通过共享变量方式；
*/
this.toStop = true;
this.stopReason = stopReason;
}
/**
* is running job
* @return
*/
public boolean isRunningOrHasQueue() {
return running || triggerQueue.size()>0;
}
@Override
public void run() {
// init
try {
handler.init();
} catch (Throwable e) {
logger.error(e.getMessage(), e);
}
// execute
while(!toStop){
running = false;
idleTimes++;
TriggerParam triggerParam = null;
try {
// to check toStop signal, we need cycle, so wo cannot use queue.take(), instand of poll(timeout)
triggerParam = triggerQueue.poll(3L, TimeUnit.SECONDS);
if (triggerParam!=null) {
running = true;
idleTimes = 0;
triggerLogIdSet.remove(triggerParam.getLogId());
// log filename, like "logPath/yyyy-MM-dd/9999.log"
String logFileName = XxlJobFileAppender.makeLogFileName(new Date(triggerParam.getLogDateTime()), triggerParam.getLogId());
XxlJobContext xxlJobContext = new XxlJobContext(
triggerParam.getJobId(),
triggerParam.getExecutorParams(),
logFileName,
triggerParam.getBroadcastIndex(),
triggerParam.getBroadcastTotal());
// init job context
XxlJobContext.setXxlJobContext(xxlJobContext);
// execute
XxlJobHelper.log("<br>----------- xxl-job job execute start -----------<br>----------- Param:" + xxlJobContext.getJobParam());
if (triggerParam.getExecutorTimeout() > 0) {
// limit timeout
Thread futureThread = null;
try {
FutureTask<Boolean> futureTask = new FutureTask<Boolean>(new Callable<Boolean>() {
@Override
public Boolean call() throws Exception {
// init job context
XxlJobContext.setXxlJobContext(xxlJobContext);
handler.execute();
return true;
}
});
futureThread = new Thread(futureTask);
futureThread.start();
Boolean tempResult = futureTask.get(triggerParam.getExecutorTimeout(), TimeUnit.SECONDS);
} catch (TimeoutException e) {
XxlJobHelper.log("<br>----------- xxl-job job execute timeout");
XxlJobHelper.log(e);
// handle result
XxlJobHelper.handleTimeout("job execute timeout ");
} finally {
futureThread.interrupt();
}
} else {
// just execute
handler.execute();
}
// valid execute handle data
if (XxlJobContext.getXxlJobContext().getHandleCode() <= 0) {
XxlJobHelper.handleFail("job handle result lost.");
} else {
String tempHandleMsg = XxlJobContext.getXxlJobContext().getHandleMsg();
tempHandleMsg = (tempHandleMsg!=null&&tempHandleMsg.length()>50000)
?tempHandleMsg.substring(0, 50000).concat("...")
:tempHandleMsg;
XxlJobContext.getXxlJobContext().setHandleMsg(tempHandleMsg);
}
XxlJobHelper.log("<br>----------- xxl-job job execute end(finish) -----------<br>----------- Result: handleCode="
+ XxlJobContext.getXxlJobContext().getHandleCode()
+ ", handleMsg = "
+ XxlJobContext.getXxlJobContext().getHandleMsg()
);
} else {
if (idleTimes > 30) {
if(triggerQueue.size() == 0) { // avoid concurrent trigger causes jobId-lost
XxlJobExecutor.removeJobThread(jobId, "excutor idel times over limit.");
}
}
}
} catch (Throwable e) {
if (toStop) {
XxlJobHelper.log("<br>----------- JobThread toStop, stopReason:" + stopReason);
}
// handle result
StringWriter stringWriter = new StringWriter();
e.printStackTrace(new PrintWriter(stringWriter));
String errorMsg = stringWriter.toString();
XxlJobHelper.handleFail(errorMsg);
XxlJobHelper.log("<br>----------- JobThread Exception:" + errorMsg + "<br>----------- xxl-job job execute end(error) -----------");
} finally {
if(triggerParam != null) {
// callback handler info
if (!toStop) {
// commonm
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(
triggerParam.getLogId(),
triggerParam.getLogDateTime(),
XxlJobContext.getXxlJobContext().getHandleCode(),
XxlJobContext.getXxlJobContext().getHandleMsg() )
);
} else {
// is killed
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(
triggerParam.getLogId(),
triggerParam.getLogDateTime(),
XxlJobContext.HANDLE_CODE_FAIL,
stopReason + " [job running, killed]" )
);
}
}
}
}
// callback trigger request in queue
while(triggerQueue !=null && triggerQueue.size()>0){
TriggerParam triggerParam = triggerQueue.poll();
if (triggerParam!=null) {
// is killed
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(
triggerParam.getLogId(),
triggerParam.getLogDateTime(),
XxlJobContext.HANDLE_CODE_FAIL,
stopReason + " [job not executed, in the job queue, killed.]")
);
}
}
// destroy
try {
handler.destroy();
} catch (Throwable e) {
logger.error(e.getMessage(), e);
}
logger.info(">>>>>>>>>>> xxl-job JobThread stoped, hashCode:{}", Thread.currentThread());
}
}
3 总结
xxl-job-core 核心就是执行器，我们再来看一下xxl-job-core的执行原理：
Spring集成环境下：
-
Spring容器初始化
-
容器化初始完成后
-
注册处理器，通过扫描Spring容器中标有注解的任务处理器
-
启动执行器
-
初始化日志
-
初始化rpc调用方（调度中心）列表
-
初始化任务日志文件清理
-
这里会调用JobLogFileCleanThread线程，每天调用一次文件清理
-
初始化任务触发器回调TriggerCallbackThread（反馈调度结果）
-
初始化rpc提供方，将address, ip, port, appname, accessToken设置到执行服务中
- 创建执行服务器（Netty HTTP服务）
- 创建向调度中心发生心跳的线程
-
-
任务调度中心admin调度服务
-
启动任务执行线程
-
通过任务线程，调用对应处理器执行任务
-
向任务调度中心反馈调度结果
-
销毁任务执行线程
