[helix] 17/21: Metaclient - Leader election - leader change event notification (#2560)
This is an automated email from the ASF dual-hosted git repository.
jxue pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/helix.git
commit 4eacde3312265e5184708f59641451bccb649ca0
Author: xyuanlu
AuthorDate: Sat Jul 22 22:39:37 2023 -0700
Metaclient - Leader election - leader change event notification (#2560)
Co-authored-by: Xiaoyuan Lu
---
.../impl/zk/adapter/DataListenerAdapter.java | 1 +
.../leaderelection/LeaderElectionClient.java | 4 +-
.../LeaderElectionListenerInterface.java | 15 ++-
.../LeaderElectionListenerInterfaceAdapter.java| 43 +++
.../zk/TestConnectStateChangeListenerAndRetry.java | 3 +-
.../recipes/leaderelection/TestLeaderElection.java | 135 -
.../helix/zookeeper/zkclient/ZkConnection.java | 1 -
7 files changed, 193 insertions(+), 9 deletions(-)
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
b/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
index 94ae198ce..748b6ed3f 100644
---
a/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
+++
b/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
@@ -21,6 +21,7 @@ package org.apache.helix.metaclient.impl.zk.adapter;
import org.apache.helix.metaclient.api.DataChangeListener;
import org.apache.helix.zookeeper.zkclient.IZkDataListener;
+import org.apache.helix.zookeeper.zkclient.annotation.PreFetchChangedData;
import org.apache.zookeeper.Watcher;
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
index 39233e979..7b13778c0 100644
---
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
+++
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
@@ -334,7 +334,8 @@ public class LeaderElectionClient implements AutoCloseable {
* @return A boolean value indicating if registration is success.
*/
public boolean subscribeLeadershipChanges(String leaderPath,
LeaderElectionListenerInterface listener) {
-//TODO: add converter class for LeaderElectionListenerInterface
+_metaClient.subscribeDataChange(leaderPath + LEADER_ENTRY_KEY, new
LeaderElectionListenerInterfaceAdapter(listener),
+false);
return false;
}
@@ -343,6 +344,7 @@ public class LeaderElectionClient implements AutoCloseable {
* @param listener An implementation of LeaderElectionListenerInterface
*/
public void unsubscribeLeadershipChanges(String leaderPath,
LeaderElectionListenerInterface listener) {
+_metaClient.unsubscribeDataChange(leaderPath + LEADER_ENTRY_KEY, new
LeaderElectionListenerInterfaceAdapter(listener));
}
@Override
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
index 0436e1eb0..230fc2af1 100644
---
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
+++
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
@@ -24,9 +24,16 @@ package org.apache.helix.metaclient.recipes.leaderelection;
* leader node is deleted.
*/
public interface LeaderElectionListenerInterface {
+ enum ChangeType {
+LEADER_ACQUIRED,
+LEADER_LOST
+ }
+
// When new leader is elected:
- // noLeader (null) ->has
leader (new leader name)
- // When existing leader not leader anymore:
- // has Leader (prevleader name) ->no
leader (null)
- public void onLeadershipChange(String leaderPath, String prevLeader, String
curLeader);
+ // ChangeType == NEW_LEADER_ELECTED, curLeader is
the new leader name
+ // When no leader anymore:
+ // ChangeType == LEADER_GONE, curLeader is an empty
string
+ // In ZK implementation, since notification does not include changed data
and metaclient fetches
+ // the entry when event comes, it is possible that
+ public void onLeadershipChange(String leaderPath, ChangeType type, String
curLeader);
}
\ No newline at end of file
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterfaceAdapter.java
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterfaceAdapter.java
new file mode 100644
index 0..5c64d6790
--- /dev/null
+++
[helix] 17/21: Metaclient - Leader election - leader change event notification (#2560)
This is an automated email from the ASF dual-hosted git repository.
jxue pushed a commit to branch metaclient
in repository https://gitbox.apache.org/repos/asf/helix.git
commit dd95ca441faa43ddec07f30ff7c15aea67e3aaa3
Author: xyuanlu
AuthorDate: Sat Jul 22 22:39:37 2023 -0700
Metaclient - Leader election - leader change event notification (#2560)
Co-authored-by: Xiaoyuan Lu
---
.../impl/zk/adapter/DataListenerAdapter.java | 1 +
.../leaderelection/LeaderElectionClient.java | 4 +-
.../LeaderElectionListenerInterface.java | 15 ++-
.../LeaderElectionListenerInterfaceAdapter.java| 43 +++
.../zk/TestConnectStateChangeListenerAndRetry.java | 3 +-
.../recipes/leaderelection/TestLeaderElection.java | 135 -
.../helix/zookeeper/zkclient/ZkConnection.java | 1 -
7 files changed, 193 insertions(+), 9 deletions(-)
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
b/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
index 94ae198ce..748b6ed3f 100644
---
a/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
+++
b/meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/adapter/DataListenerAdapter.java
@@ -21,6 +21,7 @@ package org.apache.helix.metaclient.impl.zk.adapter;
import org.apache.helix.metaclient.api.DataChangeListener;
import org.apache.helix.zookeeper.zkclient.IZkDataListener;
+import org.apache.helix.zookeeper.zkclient.annotation.PreFetchChangedData;
import org.apache.zookeeper.Watcher;
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
index 39233e979..7b13778c0 100644
---
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
+++
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
@@ -334,7 +334,8 @@ public class LeaderElectionClient implements AutoCloseable {
* @return A boolean value indicating if registration is success.
*/
public boolean subscribeLeadershipChanges(String leaderPath,
LeaderElectionListenerInterface listener) {
-//TODO: add converter class for LeaderElectionListenerInterface
+_metaClient.subscribeDataChange(leaderPath + LEADER_ENTRY_KEY, new
LeaderElectionListenerInterfaceAdapter(listener),
+false);
return false;
}
@@ -343,6 +344,7 @@ public class LeaderElectionClient implements AutoCloseable {
* @param listener An implementation of LeaderElectionListenerInterface
*/
public void unsubscribeLeadershipChanges(String leaderPath,
LeaderElectionListenerInterface listener) {
+_metaClient.unsubscribeDataChange(leaderPath + LEADER_ENTRY_KEY, new
LeaderElectionListenerInterfaceAdapter(listener));
}
@Override
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
index 0436e1eb0..230fc2af1 100644
---
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
+++
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterface.java
@@ -24,9 +24,16 @@ package org.apache.helix.metaclient.recipes.leaderelection;
* leader node is deleted.
*/
public interface LeaderElectionListenerInterface {
+ enum ChangeType {
+LEADER_ACQUIRED,
+LEADER_LOST
+ }
+
// When new leader is elected:
- // noLeader (null) ->has
leader (new leader name)
- // When existing leader not leader anymore:
- // has Leader (prevleader name) ->no
leader (null)
- public void onLeadershipChange(String leaderPath, String prevLeader, String
curLeader);
+ // ChangeType == NEW_LEADER_ELECTED, curLeader is
the new leader name
+ // When no leader anymore:
+ // ChangeType == LEADER_GONE, curLeader is an empty
string
+ // In ZK implementation, since notification does not include changed data
and metaclient fetches
+ // the entry when event comes, it is possible that
+ public void onLeadershipChange(String leaderPath, ChangeType type, String
curLeader);
}
\ No newline at end of file
diff --git
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterfaceAdapter.java
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionListenerInterfaceAdapter.java
new file mode 100644
index 0..5c64d6790
--- /dev/null
+++
