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本文基于 Elastic-Job V2.1.5 版本分享
1. 概述2. 作业分片条件3. 分配作业分片项4. 获取作业分片上下文集合666. 彩
本文主要分享 Elastic-Job-Lite 作业分片。
涉及到主要类的类图如下( 打开大图 ):
com.dangdang.ddframe.job.lite.internal.sharding
包下,实现了 Elastic-Job-Lite 作业分片。你行好事会因为得到赞赏而愉悦 同理,开源项目贡献者会因为 Star 而更加有动力 为 Elastic-Job 点赞!传送门
当作业满足分片条件时,不会立即进行作业分片分配,而是设置需要重新进行分片的标记,等到作业分片获取时,判断有该标记后执行作业分配。
设置需要重新进行分片的标记的代码如下:
// ShardingService.java
/**
* 设置需要重新分片的标记.
*/
public void setReshardingFlag() {
jobNodeStorage.createJobNodeIfNeeded(ShardingNode.NECESSARY);
}
// JobNodeStorage.java
/**
* 如果存在则创建作业节点.
* 如果作业根节点不存在表示作业已经停止, 不再继续创建节点.
*
* @param node 作业节点名称
*/
public void createJobNodeIfNeeded(final String node) {
if (isJobRootNodeExisted() && !isJobNodeExisted(node)) {
regCenter.persist(jobNodePath.getFullPath(node), "");
}
}
#setReshardingFlag()
方法设置需要重新分片的标记/${JOB_NAME}/leader/sharding/necessary
。该 Zookeeper 数据节点是永久节点,存储空串( ""
),使用 zkClient 查看如下:
[zk: localhost:2181(CONNECTED) 2] ls /elastic-job-example-lite-java/javaSimpleJob/leader/sharding [necessary] [zk: localhost:2181(CONNECTED) 3] get /elastic-job-example-lite-java/javaSimpleJob/leader/sharding/necessary#isNeedSharding()
方法即可判断是否需要重新分片。
// ShardingService.java /** * 判断是否需要重分片. * * @return 是否需要重分片 */ public boolean isNeedSharding() { return jobNodeStorage.isJobNodeExisted(ShardingNode.NECESSARY); } // JobNodeStorage.java /** * 判断作业节点是否存在. * * @param node 作业节点名称 * @return 作业节点是否存在 */ public boolean isJobNodeExisted(final String node) { return regCenter.isExisted(jobNodePath.getFullPath(node)); }设置需要重新进行分片有 4 种情况
第一种,注册作业启动信息时。
// SchedulerFacade.java
public void registerStartUpInfo(final boolean enabled) {
// ... 省略无关代码
// 设置 需要重新分片的标记
shardingService.setReshardingFlag();
// ... 省略无关代码
}
第二种,作业分片总数( JobCoreConfiguration.shardingTotalCount
)变化时。
// ShardingTotalCountChangedJobListener.java
class ShardingTotalCountChangedJobListener extends AbstractJobListener {
@Override
protected void dataChanged(final String path, final Type eventType, final String data) {
if (configNode.isConfigPath(path)
&& 0 != JobRegistry.getInstance().getCurrentShardingTotalCount(jobName)) {
int newShardingTotalCount = LiteJobConfigurationGsonFactory.fromJson(data).getTypeConfig().getCoreConfig().getShardingTotalCount();
if (newShardingTotalCount != JobRegistry.getInstance().getCurrentShardingTotalCount(jobName)) { // 作业分片总数变化
// 设置需要重新分片的标记
shardingService.setReshardingFlag();
// 设置当前分片总数
JobRegistry.getInstance().setCurrentShardingTotalCount(jobName, newShardingTotalCount);
}
}
}
}
第三种,服务器变化时。
// ShardingListenerManager.java
class ListenServersChangedJobListener extends AbstractJobListener {
@Override
protected void dataChanged(final String path, final Type eventType, final String data) {
if (!JobRegistry.getInstance().isShutdown(jobName)
&& (isInstanceChange(eventType, path)
|| isServerChange(path))) {
shardingService.setReshardingFlag();
}
}
private boolean isInstanceChange(final Type eventType, final String path) {
return instanceNode.isInstancePath(path) && Type.NODE_UPDATED != eventType;
}
private boolean isServerChange(final String path) {
return serverNode.isServerPath(path);
}
}
#isServerChange(…)
服务器被开启或禁用。#isInstanceChange(…)
作业节点新增或者移除。第四种,在《Elastic-Job-Lite 源码解析 —— 自诊断修复》详细分享。
调用 ShardingService#shardingIfNecessary()
方法,如果需要分片且当前节点为主节点, 则作业分片。
总体流程如下顺序图:( 打开大图 ):
实现代码如下:
// ShardingService.java
/**
* 如果需要分片且当前节点为主节点, 则作业分片.
*
* 如果当前无可用节点则不分片.
*/
public void shardingIfNecessary() {
List<JobInstance> availableJobInstances = instanceService.getAvailableJobInstances();
if (!isNeedSharding() // 判断是否需要重新分片
|| availableJobInstances.isEmpty()) {
return;
}
// 【非主节点】等待 作业分片项分配完成
if (!leaderService.isLeaderUntilBlock()) { // 判断是否为【主节点】
blockUntilShardingCompleted();
return;
}
// 【主节点】作业分片项分配
// 等待 作业未在运行中状态
waitingOtherJobCompleted();
//
LiteJobConfiguration liteJobConfig = configService.load(false);
int shardingTotalCount = liteJobConfig.getTypeConfig().getCoreConfig().getShardingTotalCount();
// 设置 作业正在重分片的标记
log.debug("Job '{}' sharding begin.", jobName);
jobNodeStorage.fillEphemeralJobNode(ShardingNode.PROCESSING, "");
// 重置 作业分片项信息
resetShardingInfo(shardingTotalCount);
// 【事务中】设置 作业分片项信息
JobShardingStrategy jobShardingStrategy = JobShardingStrategyFactory.getStrategy(liteJobConfig.getJobShardingStrategyClass());
jobNodeStorage.executeInTransaction(new PersistShardingInfoTransactionExecutionCallback(jobShardingStrategy.sharding(availableJobInstances, jobName, shardingTotalCount)));
log.debug("Job '{}' sharding complete.", jobName);
}
#isNeedSharding()
方法判断是否需要重新分片。LeaderService#isLeaderUntilBlock()
方法判断是否为主节点。作业分片项的分配过程:LeaderService#isLeaderUntilBlock()
方法在《Elastic-Job-Lite 源码分析 —— 主节点选举》「3. 选举主节点」有详细分享。#blockUntilShardingCompleted()
方法【非主节点】等待作业分片项分配完成。
private void blockUntilShardingCompleted() { while (!leaderService.isLeaderUntilBlock() // 当前作业节点不为【主节点】 && (jobNodeStorage.isJobNodeExisted(ShardingNode.NECESSARY) // 存在作业需要重分片的标记 || jobNodeStorage.isJobNodeExisted(ShardingNode.PROCESSING))) { // 存在作业正在重分片的标记 log.debug("Job '{}' sleep short time until sharding completed.", jobName); BlockUtils.waitingShortTime(); } }#LeaderService#isLeaderUntilBlock()
方法判断是否为主节点。为什么上面判断了一次,这里又判断一次?主节点作业分片项分配过程中,不排除自己挂掉了,此时【非主节点】若选举成主节点,无需继续等待,当然也不能等待,因为已经没节点在执行作业分片项分配,所有节点都会卡在这里。#waitingOtherJobCompleted()
方法等待作业未在运行中状态。作业是否在运行中需要 LiteJobConfiguration.monitorExecution = true
,《Elastic-Job-Lite 源码分析 —— 作业执行》「4.6 执行普通触发的作业」有详细分享。ConfigurationService#load(…)
方法从注册中心获取作业配置( 非缓存 ),避免主节点本地作业配置可能非最新的,主要目的是获得作业分片总数( shardingTotalCount
)。jobNodeStorage.fillEphemeralJobNode(ShardingNode.PROCESSING, "")
设置作业正在重分片的标记 /${JOB_NAME}/leader/sharding/processing
。该 Zookeeper 数据节点是临时节点,存储空串( ""
),仅用于标记作业正在重分片,无特别业务逻辑。#resetShardingInfo(...)
方法重置作业分片信息。
private void resetShardingInfo(final int shardingTotalCount) { // 重置 有效的作业分片项 for (int i = 0; i < shardingTotalCount; i++) { jobNodeStorage.removeJobNodeIfExisted(ShardingNode.getInstanceNode(i)); // 移除 /${JOB_NAME}/sharding/${ITEM_ID}/instance jobNodeStorage.createJobNodeIfNeeded(ShardingNode.ROOT + "/" + i); // 创建 /${JOB_NAME}/sharding/${ITEM_ID} } // 移除 多余的作业分片项 int actualShardingTotalCount = jobNodeStorage.getJobNodeChildrenKeys(ShardingNode.ROOT).size(); if (actualShardingTotalCount > shardingTotalCount) { for (int i = shardingTotalCount; i < actualShardingTotalCount; i++) { jobNodeStorage.removeJobNodeIfExisted(ShardingNode.ROOT + "/" + i); // 移除 /${JOB_NAME}/sharding/${ITEM_ID} } } }JobShardingStrategy#sharding(…)
方法计算每个节点分配的作业分片项。《Elastic-Job-Lite 源码分析 —— 作业分片策略》有详细分享。JobNodeStorage#executeInTransaction(...)
+ PersistShardingInfoTransactionExecutionCallback#execute()
方法实现在事务中设置每个节点分配的作业分片项。
// PersistShardingInfoTransactionExecutionCallback.java class PersistShardingInfoTransactionExecutionCallback implements TransactionExecutionCallback { /** * 作业分片项分配结果 * key:作业节点 * value:作业分片项 */ private final Map<JobInstance, List<Integer>> shardingResults; @Override public void execute(final CuratorTransactionFinal curatorTransactionFinal) throws Exception { // 设置 每个节点分配的作业分片项 for (Map.Entry<JobInstance, List<Integer>> entry : shardingResults.entrySet()) { for (int shardingItem : entry.getValue()) { curatorTransactionFinal.create().forPath(jobNodePath.getFullPath(ShardingNode.getInstanceNode(shardingItem)) , entry.getKey().getJobInstanceId().getBytes()).and(); } } // 移除 作业需要重分片的标记、作业正在重分片的标记 curatorTransactionFinal.delete().forPath(jobNodePath.getFullPath(ShardingNode.NECESSARY)).and(); curatorTransactionFinal.delete().forPath(jobNodePath.getFullPath(ShardingNode.PROCESSING)).and(); } } // JobNodeStorage.java /** * 在事务中执行操作. * * @param callback 执行操作的回调 */ public void executeInTransaction(final TransactionExecutionCallback callback) { try { CuratorTransactionFinal curatorTransactionFinal = getClient().inTransaction().check().forPath("/").and(); callback.execute(curatorTransactionFinal); curatorTransactionFinal.commit(); } catch (final Exception ex) { RegExceptionHandler.handleException(ex); } }
[zk: localhost:2181(CONNECTED) 0] get /elastic-job-example-lite-java/javaSimpleJob/sharding/0/instance 192.168.3.2@-@31492/${JOB_NAME}/sharding/${ITEM_ID}/instance
为分配的作业节点的作业实例主键( jobInstanceId
)。使用 zkClient 查看如下:作业分片项分配整体流程有点长,耐着心看,毕竟是核心代码哟。如果中间有任何疑问,欢迎给我公众号:芋道源码 留言。
在《Elastic-Job-Lite 源码分析 —— 作业执行的》「4.2 获取当前作业服务器的分片上下文」中,我们可以看到作业执行器( AbstractElasticJobExecutor ) 执行作业时,会获取当前作业服务器的分片上下文进行执行。获取过程总体如下顺序图( 打开大图 ):
实现代码如下:
// LiteJobFacade.java
@Override
public ShardingContexts getShardingContexts() {
// 【忽略,作业失效转移详解】获得 失效转移的作业分片项
boolean isFailover = configService.load(true).isFailover();
if (isFailover) {
List<Integer> failoverShardingItems = failoverService.getLocalFailoverItems();
if (!failoverShardingItems.isEmpty()) {
return executionContextService.getJobShardingContext(failoverShardingItems);
}
}
// 作业分片,如果需要分片且当前节点为主节点
shardingService.shardingIfNecessary();
// 获得 分配在本机的作业分片项
List<Integer> shardingItems = shardingService.getLocalShardingItems();
// 【忽略,作业失效转移详解】移除 分配在本机的失效转移的作业分片项目
if (isFailover) {
shardingItems.removeAll(failoverService.getLocalTakeOffItems());
}
// 移除 被禁用的作业分片项
shardingItems.removeAll(executionService.getDisabledItems(shardingItems));
// 获取当前作业服务器分片上下文
return executionContextService.getJobShardingContext(shardingItems);
}
ShardingService#shardingIfNecessary()
方法,如果需要分片且当前节点为主节点,作业分片项分配。不是每次都需要作业分片,必须满足「2. 作业分片条件」才执行作业分片。ShardingService#getLocalShardingItems()
方法,获得分配在本机的作业分片项,即 /${JOB_NAME}/sharding/${ITEM_ID}/instance
为本机的作业分片项。
// ShardingService.java /** * 获取运行在本作业实例的分片项集合. * * @return 运行在本作业实例的分片项集合 */ public List<Integer> getLocalShardingItems() { if (JobRegistry.getInstance().isShutdown(jobName) || !serverService.isAvailableServer(JobRegistry.getInstance().getJobInstance(jobName).getIp())) { return Collections.emptyList(); } return getShardingItems(JobRegistry.getInstance().getJobInstance(jobName).getJobInstanceId()); } /** * 获取作业运行实例的分片项集合. * * @param jobInstanceId 作业运行实例主键 * @return 作业运行实例的分片项集合 */ public List<Integer> getShardingItems(final String jobInstanceId) { JobInstance jobInstance = new JobInstance(jobInstanceId); if (!serverService.isAvailableServer(jobInstance.getIp())) { return Collections.emptyList(); } List<Integer> result = new LinkedList<>(); int shardingTotalCount = configService.load(true).getTypeConfig().getCoreConfig().getShardingTotalCount(); for (int i = 0; i < shardingTotalCount; i++) { // /${JOB_NAME}/sharding/${ITEM_ID}/instance if (jobInstance.getJobInstanceId().equals(jobNodeStorage.getJobNodeData(ShardingNode.getInstanceNode(i)))) { result.add(i); } } return result; }shardingItems.removeAll(executionService.getDisabledItems(shardingItems))
,移除被禁用的作业分片项,即 /${JOB_NAME}/sharding/${ITEM_ID}/disabled
存在的作业分片项。
// ExecutionService.java /** * 获取禁用的任务分片项. * * @param items 需要获取禁用的任务分片项 * @return 禁用的任务分片项 */ public List<Integer> getDisabledItems(final List<Integer> items) { List<Integer> result = new ArrayList<>(items.size()); for (int each : items) { // /¨E123EJOB¨E95ENAME¨E125E/sharding/<annotation encoding="application style="color: rgb(150, 152, 150);overflow-wrap: inherit !important;word-break: inherit !important;" span="" class="hljs-comment" encoding=""application"><span class="katex-html" aria-hidden="true" style="overflow-wrap: inherit !important;word-break: inherit !important;"><span class="strut" style="height:1em;vertical-align:-0.25em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">¨<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E123<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E<span class="mord mathit" style="margin-right:0.09618em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">J<span class="mord mathit" style="margin-right:0.02778em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">O<span class="mord mathit" style="margin-right:0.05017em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">B¨<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E95<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E<span class="mord mathit" style="margin-right:0.10903em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">N<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">A<span class="mord mathit" style="margin-right:0.10903em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">M<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E¨<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E125<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E/<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">s<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">h<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">a<span class="mord mathit" style="margin-right:0.02778em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">r<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">d<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">i<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">n<span class="mord mathit" style="margin-right:0.03588em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">g/{ITEM_ID}/disabled if (jobNodeStorage.isJobNodeExisted(ShardingNode.getDisabledNode(each))) { result.add(each); } } return result; } </span class="mord mathit" style="margin-right:0.03588em;"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit" style="margin-right:0.02778em;"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.10903em;"></span class="mord mathit"></span class="mord mathit" style="margin-right:0.10903em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05017em;"></span class="mord mathit" style="margin-right:0.02778em;"></span class="mord mathit" style="margin-right:0.09618em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="strut" style="height:1em;vertical-align:-0.25em;"></span class="katex-html" aria-hidden="true"></annotation encoding="application>ExecutionContextService#getJobShardingContext(…)
方法,获取当前作业服务器分片上下文。获取当前作业服务器分片上下文
调用 ExecutionContextService#getJobShardingContext(...)
方法,获取当前作业服务器分片上下文:
// ExecutionContextService.java
public ShardingContexts getJobShardingContext(final List<Integer> shardingItems) {
LiteJobConfiguration liteJobConfig = configService.load(false);
// 移除 正在运行中的作业分片项
removeRunningIfMonitorExecution(liteJobConfig.isMonitorExecution(), shardingItems);
//
if (shardingItems.isEmpty()) {
return new ShardingContexts(buildTaskId(liteJobConfig, shardingItems), liteJobConfig.getJobName(), liteJobConfig.getTypeConfig().getCoreConfig().getShardingTotalCount(),
liteJobConfig.getTypeConfig().getCoreConfig().getJobParameter(), Collections.<Integer, String>emptyMap());
}
// 解析分片参数
Map<Integer, String> shardingItemParameterMap = new ShardingItemParameters(liteJobConfig.getTypeConfig().getCoreConfig().getShardingItemParameters()).getMap();
// 创建 分片上下文集合
return new ShardingContexts(buildTaskId(liteJobConfig, shardingItems), //
liteJobConfig.getJobName(), liteJobConfig.getTypeConfig().getCoreConfig().getShardingTotalCount(),
liteJobConfig.getTypeConfig().getCoreConfig().getJobParameter(),
getAssignedShardingItemParameterMap(shardingItems, shardingItemParameterMap)); // 获得当前作业节点的分片参数
}
#removeRunningIfMonitorExecution()
方法,移除正在运行中的作业分片项。
private void removeRunningIfMonitorExecution(final boolean monitorExecution, final List<Integer> shardingItems) { if (!monitorExecution) { return; } List<Integer> runningShardingItems = new ArrayList<>(shardingItems.size()); for (int each : shardingItems) { if (isRunning(each)) { runningShardingItems.add(each); // /¨E123EJOB¨E95ENAME¨E125E/sharding/<annotation encoding="application style="color: rgb(150, 152, 150);overflow-wrap: inherit !important;word-break: inherit !important;" span="" class="hljs-comment" encoding=""application"><span class="katex-html" aria-hidden="true" style="overflow-wrap: inherit !important;word-break: inherit !important;"><span class="strut" style="height:1em;vertical-align:-0.25em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">¨<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E123<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E<span class="mord mathit" style="margin-right:0.09618em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">J<span class="mord mathit" style="margin-right:0.02778em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">O<span class="mord mathit" style="margin-right:0.05017em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">B¨<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E95<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E<span class="mord mathit" style="margin-right:0.10903em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">N<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">A<span class="mord mathit" style="margin-right:0.10903em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">M<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E¨<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E125<span class="mord mathit" style="margin-right:0.05764em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">E/<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">s<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">h<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">a<span class="mord mathit" style="margin-right:0.02778em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">r<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">d<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">i<span class="mord mathit" style="overflow-wrap: inherit !important;word-break: inherit !important;">n<span class="mord mathit" style="margin-right:0.03588em;" style="overflow-wrap: inherit !important;word-break: inherit !important;">g/{ITEM_ID}/running } } shardingItems.removeAll(runningShardingItems); } private boolean isRunning(final int shardingItem) { return jobNodeStorage.isJobNodeExisted(ShardingNode.getRunningNode(shardingItem)); } </span class="mord mathit" style="margin-right:0.03588em;"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit" style="margin-right:0.02778em;"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.10903em;"></span class="mord mathit"></span class="mord mathit" style="margin-right:0.10903em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05017em;"></span class="mord mathit" style="margin-right:0.02778em;"></span class="mord mathit" style="margin-right:0.09618em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="mord mathit" style="margin-right:0.05764em;"></span class="strut" style="height:1em;vertical-align:-0.25em;"></span class="katex-html" aria-hidden="true"></annotation encoding="application>JobCoreConfiguration.shardingItemParameters="0=Beijing,1=Shanghai,2=Guangzhou"
) 解析结果:
#buildTaskId(...)
方法,创建作业任务ID( ShardingContexts.taskId
):
private String buildTaskId(final LiteJobConfiguration liteJobConfig, final List<Integer> shardingItems) { JobInstance jobInstance = JobRegistry.getInstance().getJobInstance(jobName); return Joiner.on("@-@").join(liteJobConfig.getJobName(), Joiner.on(",").join(shardingItems), "READY", null == jobInstance.getJobInstanceId() ? "127.0.0.1@-@1" : jobInstance.getJobInstanceId()); }taskId
= ${JOB_NAME}
+ @-@
+ ${SHARDING_ITEMS}
+ @-@
+ READY
+ @-@
+ ${IP}
+ @-@
+ ${PID}
。例如:javaSimpleJob@-@0,1,2@-@READY@-@192.168.3.2@-@38330
。#getAssignedShardingItemParameterMap(...)
方法,获得当前作业节点的分片参数。
private Map<Integer, String> getAssignedShardingItemParameterMap(final List<Integer> shardingItems, final Map<Integer, String> shardingItemParameterMap) { Map<Integer, String> result = new HashMap<>(shardingItemParameterMap.size(), 1); for (int each : shardingItems) { result.put(each, shardingItemParameterMap.get(each)); } return result; }
jobEventSamplingCount
,currentJobEventSamplingCount
在 Elastic-Job-Lite 暂未还使用,在 Elastic-Job-Cloud 使用。旁白君:小伙伴,更新了干货嘛,双击 666。 芋道君:那必须的嘛,而且这么勤快更新!是不是应该分享一波朋友圈。
道友,赶紧上车,分享一波朋友圈!