elastic-job路径

# master 临时节点  值比如: 192.16.67.21@-@227032
/${JOB_NAME}/leader/electron/instance


# 具体的服务ip 多个实例同个ip，servers下只有1个ip  持久节点
# /${JOB_NAME}/servers/192.16.67.21
/${JOB_NAME}/servers/${ip}


# 具体的服务实例，1个服务1个实例  临时节点
# /${jobName}/instances/192.16.67.21-@1234
/${jobName}/instances/${instanceId}

LeaderService

设置主节点

@RequiredArgsConstructor
class LeaderElectionExecutionCallback implements LeaderExecutionCallback {
    
    @Override
    public void execute() {
        if (!hasLeader()) { // 当前无主节点  创建临时节点/${JOB_NAME}/leader/electron/instance 为当前节点 值为${jobInstanceId}
            jobNodeStorage.fillEphemeralJobNode(LeaderNode.INSTANCE, JobRegistry.getInstance().getJobInstance(jobName).getJobInstanceId());
        }
    }
}

判断是否已经有主节点

/** 判断是否已经有主节点
 * Judge has leader or not in current time.
 * 
 * @return has leader or not in current time
 */
public boolean hasLeader() {
    return jobNodeStorage.isJobNodeExisted(LeaderNode.INSTANCE); // /${JOB_NAME}/leader/electron/instance
}

ServerService
 

/**
 * Persist online status of job server.
 * 
 * @param enabled enable server or not
 */
public void persistOnline(final boolean enabled) {
    if (!JobRegistry.getInstance().isShutdown(jobName)) { //如果当前jobName已经shutdown了  则 ${jobName}/servers/${ip} 的 值设置ENABLED或DISABLED
        jobNodeStorage.fillJobNode(serverNode.getServerNode(JobRegistry.getInstance().getJobInstance(jobName).getIp()), enabled ? ServerStatus.ENABLED.name() : ServerStatus.DISABLED.name());
    }
}

/** 是否有可用的服务器
 * Judge has available servers or not.
 * 
 * @return has available servers or not
 */
public boolean hasAvailableServers() {
    List<String> servers = jobNodeStorage.getJobNodeChildrenKeys(ServerNode.ROOT);  //  /${jobName}/servers
    for (String each : servers) {
        if (isAvailableServer(each)) {
            return true;
        }
    }
    return false;
}

/** 当前ip是否是可用的
 * Judge is available server or not.
 * 
 * @param ip job server IP address
 * @return is available server or not
 */
public boolean isAvailableServer(final String ip) {
    return isEnableServer(ip) && hasOnlineInstances(ip); // 条件1： /${jobName}/servers/${ip} 的 值:ENABLED
}

private boolean hasOnlineInstances(final String ip) { //该ip是否有在线的服务实例
    for (String each : jobNodeStorage.getJobNodeChildrenKeys(InstanceNode.ROOT)) {  //  /${jobName}/instances
        if (each.startsWith(ip)) {  // each 比如 192.16.67.21-@1234
            return true;
        }
    }
    return false;
}

/**  /${jobName}/servers/${ip} 这个路径一定要存在，否则一直等候，一直取
 * Judge is server enabled or not.
 *
 * @param ip job server IP address
 * @return is server enabled or not    true:enabled
 */
public boolean isEnableServer(final String ip) {
    String serverStatus = jobNodeStorage.getJobNodeData(serverNode.getServerNode(ip)); //  /${jobName}/servers/${ip}  值:ENABLED
    while (Strings.isNullOrEmpty(serverStatus)) { //返回是空值
        BlockUtils.waitingShortTime(); //等候100ms
        serverStatus = jobNodeStorage.getJobNodeData(serverNode.getServerNode(ip)); // 重新读取/${jobName}/servers/${ip}的值
    }
    return !ServerStatus.DISABLED.name().equals(serverStatus);
}

InstanceService

/** 临时节点  /${jobName}/instances/${instanceId}  值是空字符串
 * Persist job online status.
 */
public void persistOnline() {
    jobNodeStorage.fillEphemeralJobNode(instanceNode.getLocalInstanceNode(), "");
}

/**
 * Persist job instance.
 */
public void removeInstance() {
    jobNodeStorage.removeJobNodeIfExisted(instanceNode.getLocalInstanceNode());
}

/**
 * Clear trigger flag.
 */
public void clearTriggerFlag() {
    jobNodeStorage.updateJobNode(instanceNode.getLocalInstanceNode(), "");
}

/**  获取当前jobname下所有可用的instance
 * Get available job instances.
 *
 * @return available job instances
 */
public List<JobInstance> getAvailableJobInstances() {
    List<JobInstance> result = new LinkedList<>();
    for (String each : jobNodeStorage.getJobNodeChildrenKeys(InstanceNode.ROOT)) {  //$jobName/instances
        JobInstance jobInstance = new JobInstance(each);
        if (serverService.isEnableServer(jobInstance.getIp())) {
            result.add(new JobInstance(each));
        }
    }
    return result;
}

/** 判断/$jobName/instances/${instanceId} 是否存在
 * Judge is job instance existed or not in localhost.
 * 
 * @return is job instance existed or not in localhost
 */
public boolean isLocalJobInstanceExisted() {
    return jobNodeStorage.isJobNodeExisted(instanceNode.getLocalInstanceNode());
}