sofa-registry-meta-select (sofastack#235)

* annotation * 添加文章连接 * delete node Co-authored-by: dongdong.yang <[email protected]>
czbcxy · Jun 16, 2022 · 6e740c5 · 6e740c5
1 parent 9dc6eec
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Showing 3 changed files with 9 additions and 6 deletions.
diff --git a/README.md b/README.md
@@ -37,6 +37,7 @@ SOFARegistry 是蚂蚁金服开源的一个生产级、高时效、高可用的
 - 源码解析
    - [SlotTable](https://www.sofastack.tech/projects/sofa-registry/code-analyze/code-analyze-slottable/)
    - [发布订阅推送](https://www.sofastack.tech/projects/sofa-registry/code-analyze/code-analyze-publish-subscription-push/)
+   - [registry meta 选主](https://www.sofastack.tech/projects/sofa-registry/code-analyze/code-analyze-registry-meta/)
 
 
 ## 贡献

diff --git a/...e/api/src/main/java/com/alipay/sofa/registry/store/api/elector/AbstractLeaderElector.java b/...e/api/src/main/java/com/alipay/sofa/registry/store/api/elector/AbstractLeaderElector.java
@@ -88,7 +88,7 @@ public void waitingUnthrowable() {
 
   public void elect() {
     synchronized (this) {
-      if (isObserver) {
+      if (isObserver) {//如果是Observer，不参与选主
         leaderInfo = doQuery();
         LOG.info("meta role: Observer, leaderInfo: {}", leaderInfo);
       } else {
@@ -97,7 +97,7 @@ public void elect() {
 
       if (amILeader()) {
         onIamLeader();
-      } else {
+      } else {//我不是leader
         onIamNotLeader();
       }
     }

diff --git a/...store/jdbc/src/main/java/com/alipay/sofa/registry/jdbc/elector/MetaJdbcLeaderElector.java b/...store/jdbc/src/main/java/com/alipay/sofa/registry/jdbc/elector/MetaJdbcLeaderElector.java
@@ -52,21 +52,23 @@ public class MetaJdbcLeaderElector extends AbstractLeaderElector implements Reco
    */
   @Override
   protected LeaderInfo doElect() {
+    //1、查询锁
     DistributeLockDomain lock =
         distributeLockMapper.queryDistLock(defaultCommonConfig.getClusterId(tableName()), lockName);
 
     /** compete and return leader */
+    //2、不存在则创建锁
     if (lock == null) {
       return competeLeader(defaultCommonConfig.getClusterId(tableName()));
     }
-
+    //3、判断角色
     ElectorRole role = amILeader(lock.getOwner()) ? ElectorRole.LEADER : ElectorRole.FOLLOWER;
     if (role == ElectorRole.LEADER) {
-      lock = onLeaderWorking(lock, myself());
+      lock = onLeaderWorking(lock, myself());//4、提交心跳
     } else {
-      lock = onFollowWorking(lock, myself());
+      lock = onFollowWorking(lock, myself());//5、判断过期与否，如过期，则cas竞争锁
     }
-    LeaderInfo result = leaderFrom(lock);
+    LeaderInfo result = leaderFrom(lock);//6、锁信息转换为LeaderInfo
     LOG.info("meta role : {}, leaderInfo: {}", role, result);
     return result;
   }