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Zookeeper
Commit 68553e5c authored by abdullh.alsoleman's avatar abdullh.alsoleman
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Leader Election

parent b86192ac
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.idea/artifacts/zookeeper_jar.xml 0 → 100644
View file @ 68553e5c
<component name="ArtifactManager">
<artifact type="jar" name="zookeeper:jar">
<output-path>$PROJECT_DIR$/out/artifacts/zookeeper_jar</output-path>
<root id="archive" name="zookeeper.jar">
<element id="module-output" name="zookeeper" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-common/4.1.94.Final/netty-common-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-resolver/4.1.94.Final/netty-resolver-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-boringssl-static/2.0.61.Final/netty-tcnative-boringssl-static-2.0.61.Final-windows-x86_64.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/org/apache/yetus/audience-annotations/0.12.0/audience-annotations-0.12.0.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-boringssl-static/2.0.61.Final/netty-tcnative-boringssl-static-2.0.61.Final-osx-aarch_64.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-boringssl-static/2.0.61.Final/netty-tcnative-boringssl-static-2.0.61.Final-linux-x86_64.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-boringssl-static/2.0.61.Final/netty-tcnative-boringssl-static-2.0.61.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/org/apache/zookeeper/zookeeper-jute/3.9.1/zookeeper-jute-3.9.1.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.30/slf4j-api-1.7.30.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/commons-io/commons-io/2.11.0/commons-io-2.11.0.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-classes/2.0.61.Final/netty-tcnative-classes-2.0.61.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/ch/qos/logback/logback-core/1.2.10/logback-core-1.2.10.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-buffer/4.1.94.Final/netty-buffer-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/ch/qos/logback/logback-classic/1.2.10/logback-classic-1.2.10.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-transport/4.1.94.Final/netty-transport-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/org/apache/zookeeper/zookeeper/3.9.1/zookeeper-3.9.1.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-codec/4.1.94.Final/netty-codec-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-transport-native-unix-common/4.1.94.Final/netty-transport-native-unix-common-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-transport-classes-epoll/4.1.94.Final/netty-transport-classes-epoll-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-boringssl-static/2.0.61.Final/netty-tcnative-boringssl-static-2.0.61.Final-linux-aarch_64.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-handler/4.1.94.Final/netty-handler-4.1.94.Final.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-tcnative-boringssl-static/2.0.61.Final/netty-tcnative-boringssl-static-2.0.61.Final-osx-x86_64.jar" path-in-jar="/" />
<element id="extracted-dir" path="$MAVEN_REPOSITORY$/io/netty/netty-transport-native-epoll/4.1.94.Final/netty-transport-native-epoll-4.1.94.Final-linux-x86_64.jar" path-in-jar="/" />
</root>
</artifact>
</component>
\ No newline at end of file
.idea/misc.xml
View file @ 68553e5c
......@@ -8,7 +8,7 @@
</list>
</option>
</component>
<component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
<component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
<output url="file://$PROJECT_DIR$/out" />
</component>
</project>
\ No newline at end of file
.idea/workspace.xml
View file @ 68553e5c
<?xml version="1.0" encoding="UTF-8"?>
<project version="4">
<component name="ArtifactsWorkspaceSettings">
<artifacts-to-build>
<artifact name="zookeeper:jar" />
</artifacts-to-build>
</component>
<component name="AutoImportSettings">
<option name="autoReloadType" value="SELECTIVE" />
</component>
......@@ -34,7 +39,11 @@
"keyToString": {
"RunOnceActivity.OpenProjectViewOnStart": "true",
"RunOnceActivity.ShowReadmeOnStart": "true",
"SHARE_PROJECT_CONFIGURATION_FILES": "true"
"SHARE_PROJECT_CONFIGURATION_FILES": "true",
"last_opened_file_path": "C:/Users/Abdullah/Desktop/Java/zookeeper",
"project.structure.last.edited": "Artifacts",
"project.structure.proportion": "0.0",
"project.structure.side.proportion": "0.0"
}
}]]></component>
<component name="SpellCheckerSettings" RuntimeDictionaries="0" Folders="0" CustomDictionaries="0" DefaultDictionary="application-level" UseSingleDictionary="true" transferred="true" />
......
src/main/java/org/example/LeaderElection.java
View file @ 68553e5c
......@@ -2,29 +2,64 @@ package org.example;
import org.apache.zookeeper.*;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.data.Stat;
import java.io.IOException;
import java.net.ConnectException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
public class LeaderElection implements Watcher {
private static final String address = "192.168.56.115:2181";
private static final int SESSION_TIMEOUT = 3000; //dead client
private static final String ADDRESS = "192.168.56.115:2181";
private static final int SESSION_TIMEOUT = 3000;
private static final String ELECTION_NAMESPACE = "/election";
private String currentZnodeName;
private String leader;
private ZooKeeper zooKeeper = null;
private void volunteerForLeadership() throws InterruptedException, KeeperException {
String znodePrefix = ELECTION_NAMESPACE + "/c_";
String path = zooKeeper.create(znodePrefix, new byte[]{}, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
this.currentZnodeName = path.replace(ELECTION_NAMESPACE + "/", "");
System.out.println("Created znode: " + path);
}
private void electLeader() throws InterruptedException, KeeperException {
List<String> children = zooKeeper.getChildren(ELECTION_NAMESPACE, false);
Collections.sort(children);
leader = children.get(0);
if (currentZnodeName.equals(leader)) {
System.out.println("I'm the leader");
//set data in leader Znode.
setLeaderData(currentZnodeName);
} else {
System.out.println("I'm not the leader, the leader is " + leader);
// Set a watch on the znode with one less sequence number
int currentZnodeIndex = children.indexOf(currentZnodeName);
String previousZnode = ELECTION_NAMESPACE + "/" + children.get(currentZnodeIndex - 1);
zooKeeper.exists(previousZnode, this);
}
}
private void setLeaderData(String znodeName) {
String znodePath = ELECTION_NAMESPACE + "/" + znodeName;
try {
zooKeeper.setData(znodePath, ("The leader is " + znodeName).getBytes(), -1);
} catch (KeeperException | InterruptedException e) {
throw new RuntimeException("Error setting leader data", e);
}
}
public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
LeaderElection leaderElection = new LeaderElection();
leaderElection.connectToZookeeper();
leaderElection.volunteerForLeadership();
leaderElection.electLeader();
leaderElection.run();
}
public void connectToZookeeper() throws IOException {
this.zooKeeper = new ZooKeeper(address, SESSION_TIMEOUT, this);
this.zooKeeper = new ZooKeeper(ADDRESS, SESSION_TIMEOUT, this);
}
public void run() throws InterruptedException {
......@@ -38,6 +73,59 @@ public class LeaderElection implements Watcher {
public void process(WatchedEvent watchedEvent) {
switch (watchedEvent.getType()) {
case None:
handleNoneEvent(watchedEvent);
break;
case NodeDeleted:
handleNodeDeletedEvent(watchedEvent);
break;
case NodeDataChanged:
handleNodeDataChangedEvent(watchedEvent);
break;
}
}
private void handleNodeDeletedEvent(WatchedEvent watchedEvent) {
String deletedZnodePath = watchedEvent.getPath();
System.out.println("Znode deleted: " + deletedZnodePath);
// Check if the deleted znode is the leader
if (deletedZnodePath.equals(ELECTION_NAMESPACE + "/" + leader)) {
System.out.println("The deleted znode was the leader. Re-electing leader...");
try {
// Re-elect leader
electLeader();
} catch (InterruptedException | KeeperException e) {
throw new RuntimeException("Error re-electing leader", e);
}
}
}
private void handleNodeDataChangedEvent(WatchedEvent watchedEvent) {
String znodePath = watchedEvent.getPath();
System.out.println("Znode data changed: " + znodePath);
byte[] znodePathBytes = new byte[]{};
try {
//get data of the znode which changed its data
znodePathBytes = zooKeeper.getData(znodePath, false, null);
// Set the data of the current znode to the combined data
zooKeeper.setData(ELECTION_NAMESPACE+"/"+currentZnodeName, znodePathBytes, -1);
String data = new String(znodePathBytes);
System.out.println(data);
} catch (KeeperException e) {
throw new RuntimeException(e);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
private void handleNoneEvent(WatchedEvent watchedEvent) {
if (watchedEvent.getState() == Event.KeeperState.SyncConnected) {
System.out.println("Successfully connected to ZooKeeper");
} else if (watchedEvent.getState() == Event.KeeperState.Expired) {
......@@ -51,7 +139,5 @@ public class LeaderElection implements Watcher {
zooKeeper.notifyAll();
}
}
break;
}
}
}
src/main/resources/META-INF/MANIFEST.MF 0 → 100644
View file @ 68553e5c
Manifest-Version: 1.0
Main-Class: org.example.LeaderElection
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