Soul网关学习Zookeeper数据同步02
启动 admin，与网关。 admin 操作，使用 zookeeper 同步数据到网关
上一篇，通过 soul-admin 启动过程为入口，分析了 soul-admin 启动就会同步网关数据 rule、metaData、selector、plugin 等到 zookeeper。
数据变化会发布 DataChangedEvent 事件，监听事件将数据同步至 zookeeper。 本篇接着上一篇继续跟踪源码分析 zookeeper 同步数据到网关原理：
- soul-admin 变更网关数据，跟踪数据同步过程。
- soul-bootstrap 如何获取 zookeeper 数据的，如何感知网关数据变化的。
一、soul-admin 变更网关数据，跟踪数据同步过程
1、在网关后台尝试更改 divide 插件状态，debug 跟踪。
2、插件更新后会发布一个 DataChangedEvent 事件
3、org.dromara.soul.admin.listener.DataChangedEventDispatcher --> onApplicationEvent() 负责监听事件
4、org.dromara.soul.admin.listener.zookeeper.ZookeeperDataChangedListener 负责同步数据至 zookeeper
二、soul-bootstrap 如何获取 zookeeper 数据的，如何感知网关数据变化的。
1、soul-bootstrap 依赖
<dependency>
<groupId>org.dromara</groupId>
<artifactId>soul-spring-boot-starter-sync-data-zookeeper</artifactId>
<version>${project.version}</version>
</dependency>2、soul-bootstrap 启动后会自动注入 org.dromara.soul.spring.boot.sync.data.zookeeper.ZookeeperSyncDataConfiguration
读取 Zookeeper 配置向容器中注入 ZkClient。
SyncDataService 向容器注入数据同步服务 bean，从 Spring 容器中获取，ZkClient（zookeeper 客户端）， pluginSubscriber（插件数据订阅）、metaSubscribers （元数据订阅）、authSubscribers（权限订阅）。
public class ZookeeperSyncDataConfiguration {
/**
* Sync data service sync data service.
* @param zkClient the zk client
* @param pluginSubscriber the plugin subscriber
* @param metaSubscribers the meta subscribers
* @param authSubscribers the auth subscribers
* @return the sync data service
*/
@Bean
public SyncDataService syncDataService(final ObjectProvider<ZkClient> zkClient, final ObjectProvider<PluginDataSubscriber> pluginSubscriber,
final ObjectProvider<List<MetaDataSubscriber>> metaSubscribers, final ObjectProvider<List<AuthDataSubscriber>> authSubscribers) {
log.info("you use zookeeper sync soul data.......");
return new ZookeeperSyncDataService(zkClient.getIfAvailable(), pluginSubscriber.getIfAvailable(),
metaSubscribers.getIfAvailable(Collections::emptyList), authSubscribers.getIfAvailable(Collections::emptyList));
}
/**
* register zkClient in spring ioc.
* @param zookeeperConfig the zookeeper configuration
* @return ZkClient {@linkplain ZkClient}
*/
@Bean
public ZkClient zkClient(final ZookeeperConfig zookeeperConfig) {
return new ZkClient(zookeeperConfig.getUrl(), zookeeperConfig.getSessionTimeout(), zookeeperConfig.getConnectionTimeout());
}
}3、org.dromara.soul.sync.data.zookeeper.ZookeeperSyncDataService 初始化，也就是 soul-bootstrap 启动后就会从 zookeeper 获取数据，同步至内存。
- watcherData()--> watcherAll() --> watcherPlugin() --> cachePluginData()。
- zkClient.subscribeDataChanges() 监听 当前节点和子节点的内容修改、删除。
public class ZookeeperSyncDataService implements SyncDataService, AutoCloseable {
private final ZkClient zkClient;
private final PluginDataSubscriber pluginDataSubscriber;
private final List<MetaDataSubscriber> metaDataSubscribers;
private final List<AuthDataSubscriber> authDataSubscribers;
/**
* Instantiates a new Zookeeper cache manager.
* @param zkClient the zk client
* @param pluginDataSubscriber the plugin data subscriber
* @param metaDataSubscribers the meta data subscribers
* @param authDataSubscribers the auth data subscribers
*/
public ZookeeperSyncDataService(final ZkClient zkClient, final PluginDataSubscriber pluginDataSubscriber,
final List<MetaDataSubscriber> metaDataSubscribers, final List<AuthDataSubscriber> authDataSubscribers) {
this.zkClient = zkClient;
this.pluginDataSubscriber = pluginDataSubscriber;
this.metaDataSubscribers = metaDataSubscribers;
this.authDataSubscribers = authDataSubscribers;
watcherData();
watchAppAuth();
watchMetaData();
}
......
private void watcherData() {
final String pluginParent = ZkPathConstants.PLUGIN_PARENT;
List<String> pluginZKs = zkClientGetChildren(pluginParent);
for (String pluginName : pluginZKs) {
watcherAll(pluginName);
}
zkClient.subscribeChildChanges(pluginParent, (parentPath, currentChildren) -> {
if (CollectionUtils.isNotEmpty(currentChildren)) {
for (String pluginName : currentChildren) {
watcherAll(pluginName);
}
}
});
}
......
private void watcherPlugin(final String pluginName) {
String pluginPath = ZkPathConstants.buildPluginPath(pluginName);
if (!zkClient.exists(pluginPath)) {
zkClient.createPersistent(pluginPath, true);
}
cachePluginData(zkClient.readData(pluginPath));
subscribePluginDataChanges(pluginPath, pluginName);
}
}4、debug 过程
三、soul-bootstrap 是如何感知网关数据变化的
1、org.dromara.soul.sync.data.zookeeper.ZookeeperSyncDataService cacheRuleData 方法上打上断点，更新插件规则，观察是否会进入此断点。
private void cacheRuleData(final RuleData ruleData) {
Optional.ofNullable(ruleData)
.ifPresent(data -> Optional.ofNullable(pluginDataSubscriber).ifPresent(e -> e.onRuleSubscribe(data)));
}2、soul-admin 后台操作更改 divide 插件规则，首先 soul-admin 会发布事件，并监听事件同步更新数据至 zookeeper。
3、soul-bootstrap 确实收到了插件数据的更新，根据 Soul 官网介绍的"zookeeper 的同步原理"这里主要是依赖 zookeeper 的 watch 机制。
org.dromara.soul.sync.data.zookeeper.ZookeeperSyncDataService 类：
zkClient.subscribeDataChanges() 监听 当前节点和子节点的内容修改、删除。
zkClient.subscribeChildChanges(groupParentPath, (parentPath, currentChildren) -> {
if (CollectionUtils.isNotEmpty(currentChildren)) {
List<String> addSubscribePath = addSubscribePath(childrenList, currentChildren);
// Get the newly added node data and subscribe to that node
addSubscribePath.stream().map(addPath -> {
String realPath = buildRealPath(parentPath, addPath);
cacheRuleData(zkClient.readData(realPath));
return realPath;
}).forEach(this::subscribeRuleDataChanges);
}
});
private void subscribeRuleDataChanges(final String path) {
zkClient.subscribeDataChanges(path, new IZkDataListener() {
@Override
public void handleDataChange(final String dataPath, final Object data) {
cacheRuleData((RuleData) data);
}
@Override
public void handleDataDeleted(final String dataPath) {
unCacheRuleData(dataPath);
}
});
}
四、总结
