maxwellHA on zookeeper

bin/maxwell-leaders

@@ -0,0 +1,22 @@
+#!/bin/bash
+set -e
+
+base_dir="$(dirname "$0")/.."
+lib_dir="$base_dir/lib"
+lib_dir_development="$base_dir/target/lib"
+
+if [ ! -e "$lib_dir" -a -e "$lib_dir_development" ]; then
+        lib_dir="$lib_dir_development"
+        CLASSPATH="$CLASSPATH:$base_dir/target/classes"
+fi
+
+CLASSPATH="$CLASSPATH:$lib_dir/*"
+
+if [ -z "$JAVA_HOME" ]; then
+  JAVA="java"
+else
+  JAVA="$JAVA_HOME/bin/java"
+fi
+
+export LANG="en_US.UTF-8"
+exec $JAVA -Dlog4j.shutdownCallbackRegistry=com.djdch.log4j.StaticShutdownCallbackRegistry -cp $CLASSPATH com.zendesk.maxwell.util.MaxwellLeaders "$@"

docs/docs/high_availability.md

@@ -53,8 +53,36 @@ which can be worked around by forcing the JVM onto an ipv4 stack:
 JAVA_OPTS="-Djava.net.preferIPv4Stack=true" bin/maxwell --ha --raft_member_id=B
 ```
 
+# High Availabilty on Zookeeper
 
+High availability through zookeeper
 
+## Getting started
+Prepare two or more servers to serve as the maxwell host server and a zookeeper cluster.  (The maxwell host server and a zookeeper cluster can communicate.)
+
+Example Running Scripts:
 
+```
+    bin/maxwell --log_level='INFO' --user='<user>' --password='<passwd>' --host='<host>' --producer=stdout --client_id='<client_id>' --ha='zookeeper' --zookeeper_server ='<host1:port>,<host2:port>,<host3:port>'
+```
 
+Run the preceding command on each maxwell host.
+
+Get which host is the leader script Example:
+```
+    bin/maxwell-leaders --ha='zookeeper' --zookeeper_server ='<host1:port>,<host2:port>,<host3:port>' --client_id='<client_id>'
+```
+You can get:
+```
+    [INFO] MaxwellLeaders: clientID:<clientID>:leaders now are -> <leader host>
+```
+
+## Getting deeper
+If a timeout error occurs between the maxwell host and the zookeeper cluster or the connection is abnormal due to network instability, you can set the following parameters:
+```
+--zookeeper_session_timeout_ms=<session timeout duration> 
+--zookeeper_connection_timeout_ms=<internal default wait time for the client to establish a connection with the zk> 
+--zookeeper_max_retries=<number of retries>
+--zookeeper_retry_wait_ms=<retry time interval>
+```
 

pom.xml

@@ -387,6 +387,27 @@
       <version>1.18.0</version>
       <scope>test</scope>
     </dependency>
+    <!--zookeeper as ha-->
+    <dependency>
+      <groupId>org.apache.curator</groupId>
+      <artifactId>curator-recipes</artifactId>
+      <version>2.12.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.curator</groupId>
+      <artifactId>curator-client</artifactId>
+      <version>2.12.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.curator</groupId>
+      <artifactId>curator-framework</artifactId>
+      <version>2.12.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.zookeeper</groupId>
+      <artifactId>zookeeper</artifactId>
+      <version>3.4.13</version>
+    </dependency>
 
   </dependencies>
 

src/main/java/com/zendesk/maxwell/Maxwell.java

@@ -13,6 +13,7 @@
 import com.zendesk.maxwell.schema.*;
 import com.zendesk.maxwell.schema.columndef.ColumnDefCastException;
 import com.zendesk.maxwell.util.Logging;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -331,9 +332,18 @@ public void run() {
 
 			LOGGER.info("Starting Maxwell. maxMemory: " + Runtime.getRuntime().maxMemory() + " bufferMemoryUsage: " + config.bufferMemoryUsage);
 
-			if ( config.haMode ) {
-				new MaxwellHA(maxwell, config.jgroupsConf, config.raftMemberID, config.clientID).startHA();
-			} else {
+			if ( null != config.haMode){
+				if ( "jgroups-raft".equals(config.haMode)){
+					new MaxwellHA(maxwell, config.jgroupsConf, config.raftMemberID, config.clientID).startHAJGroups();
+				} else if ( "zookeeper".equals(config.haMode)){
+					if( StringUtils.isBlank(config.zookeeperServer)){
+						throw new Exception("In high availability mode 'zookeeperServer' does not allow Null. --zookeeper_server = " + config.zookeeperServer);
+					}
+					new MaxwellHA(maxwell, config.zookeeperServer, config.zookeeperSessionTimeoutMs, config.zookeeperConnectionTimeoutMs, config.zookeeperMaxRetries, config.zookeeperRetryWaitMs, config.clientID).startHAZookeeper();
+				} else {
+					throw new Exception("The value of ha is not in (jgroups-raft,zookeeper). ha = " + config.haMode);
+				}
+			} else{
 				maxwell.start();
 			}
 		} catch ( SQLException e ) {

src/main/java/com/zendesk/maxwell/MaxwellConfig.java

@@ -609,9 +609,9 @@ public class MaxwellConfig extends AbstractConfig {
 	public Scripting scripting;
 
 	/**
-	 * Enable high available support (via jgroups-raft)
+	 * Enable high available support (via jgroups-raft or zookeeper)
 	 */
-	public boolean haMode;
+	public String haMode;
 
 	/**
 	 * Path to raft.xml file that configures high availability support
@@ -629,6 +629,32 @@ public class MaxwellConfig extends AbstractConfig {
 	 */
 	public int binlogEventQueueSize;
 
+	/**
+	 * HA zookeeper address
+	 */
+	public String zookeeperServer;
+
+	/**
+	 * session time
+	 */
+	public int zookeeperSessionTimeoutMs;
+
+	/**
+	 * connection time
+	 */
+	public int zookeeperConnectionTimeoutMs;
+
+	/**
+	 * maxRetries
+	 */
+	public int zookeeperMaxRetries;
+
+	/**
+	 * retryWaitMs
+	 */
+	public int zookeeperRetryWaitMs;
+
+
 	/**
 	 * Build a default configuration object.
 	 */
@@ -741,12 +767,22 @@ protected MaxwellOptionParser buildOptionParser() {
 				.withRequiredArg();
 		parser.separator();
 
-		parser.accepts( "ha", "enable high-availability mode via jgroups-raft" )
-				.withOptionalArg().ofType(Boolean.class);
+		parser.accepts( "ha", "enable high-availability mode via jgroups-raft or zookeeper" )
+				.withOptionalArg();
 		parser.accepts( "jgroups_config", "location of jgroups xml configuration file" )
 				.withRequiredArg();
 		parser.accepts( "raft_member_id", "raft memberID.  (may also be specified in raft.xml)" )
 				.withRequiredArg();
+		parser.accepts("zookeeper_server","enable maxwell High Availability using zookeeper")
+				.withRequiredArg();
+		parser.accepts("zookeeper_session_timeout_ms","session timeout duration (maxwellHA on zk)")
+				.withRequiredArg().ofType(Integer.class);
+		parser.accepts("zookeeper_connection_timeout_ms","connection timeout duration (maxwellHA on zk)")
+				.withRequiredArg().ofType(Integer.class);
+		parser.accepts("zookeeper_max_retries","maximum retry (maxwellHA on zk)")
+				.withRequiredArg().ofType(Integer.class);
+		parser.accepts("zookeeper_retry_wait_ms","initial retry wait time (maxwellHA on zk)")
+				.withRequiredArg().ofType(Integer.class);
 
 		parser.separator();
 
@@ -1206,11 +1242,17 @@ private void setup(OptionSet options, Properties properties) {
 
 		setupEncryptionOptions(options, properties);
 
-		this.haMode = fetchBooleanOption("ha", options, properties, false);
+		this.haMode = fetchStringOption("ha", options, properties, null);
 		this.jgroupsConf = fetchStringOption("jgroups_config", options, properties, "raft.xml");
 		this.raftMemberID = fetchStringOption("raft_member_id", options, properties, null);
 		this.replicationReconnectionRetries = fetchIntegerOption("replication_reconnection_retries", options, properties, 1);
 
+		this.zookeeperServer = fetchStringOption("zookeeper_server", options, properties, null);
+		this.zookeeperSessionTimeoutMs = fetchIntegerOption("zookeeper_session_timeout_ms", options, properties, 6000);
+		this.zookeeperConnectionTimeoutMs = fetchIntegerOption("zookeeper_connection_timeout_ms", options, properties, 6000);
+		this.zookeeperMaxRetries = fetchIntegerOption("zookeeper_max_retries", options, properties, 3);
+		this.zookeeperRetryWaitMs = fetchIntegerOption("zookeeper_retry_wait_ms", options, properties, 1000);
+
 		this.binlogEventQueueSize = fetchIntegerOption("binlog_event_queue_size", options, properties, BinlogConnectorReplicator.BINLOG_QUEUE_SIZE);
 	}
 

src/main/java/com/zendesk/maxwell/MaxwellHA.java

@@ -1,5 +1,9 @@
 package com.zendesk.maxwell;
 
+import com.zendesk.maxwell.util.CuratorUtils;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.recipes.leader.LeaderLatch;
+import org.apache.curator.framework.recipes.leader.LeaderLatchListener;
 import org.jgroups.JChannel;
 import org.jgroups.protocols.raft.Role;
 import org.jgroups.raft.RaftHandle;
@@ -9,13 +13,15 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
- * Class that joins a jgroups-raft cluster of servers
+ * Class that joins a jgroups-raft cluster of servers or zookeeper
  */
 public class MaxwellHA {
 	static final Logger LOGGER = LoggerFactory.getLogger(MaxwellHA.class);
 
 	private final Maxwell maxwell;
-	private final String jgroupsConf, raftMemberID, clientID;
+	private String jgroupsConf, raftMemberID, clientID;
+	private String zookeeperServer;
+	private int sessionTimeoutMs, connectionTimeoutMs, maxRetries, baseSleepTimeMs;
 	private boolean hasRun = false;
 	private AtomicBoolean isRaftLeader = new AtomicBoolean(false);
 
@@ -33,6 +39,26 @@ public MaxwellHA(Maxwell maxwell, String jgroupsConf, String raftMemberID, Strin
 		this.clientID = clientID;
 	}
 
+	/**
+	 * Build a MaxwellHA object
+	 * @param maxwell The Maxwell instance that will be run when an election is won
+	 * @param zookeeperServer zookeeper adds
+	 * @param sessionTimeoutMs
+	 * @param connectionTimeoutMs
+	 * @param maxRetries
+	 * @param baseSleepTimeMs
+	 * @param clientID The maxwell clientID. This will be the only one through which the actual path is stored
+	 */
+	public MaxwellHA(Maxwell maxwell, String zookeeperServer, int sessionTimeoutMs, int connectionTimeoutMs, int maxRetries, int baseSleepTimeMs, String clientID) {
+		this.maxwell = maxwell;
+		this.zookeeperServer = zookeeperServer;
+		this.sessionTimeoutMs = sessionTimeoutMs;
+		this.connectionTimeoutMs = connectionTimeoutMs;
+		this.maxRetries = maxRetries;
+		this.baseSleepTimeMs = baseSleepTimeMs;
+		this.clientID = clientID;
+	}
+
 	private void run() {
 		try {
 			if (hasRun)
@@ -53,7 +79,7 @@ private void run() {
 	 * Does not return.
 	 * @throws Exception if there's any issues
 	 */
-	public void startHA() throws Exception {
+	public void startHAJGroups() throws Exception {
 		JChannel ch=new JChannel(jgroupsConf);
 		RaftHandle handle=new RaftHandle(ch, null);
 		if ( raftMemberID != null )
@@ -83,4 +109,51 @@ public void startHA() throws Exception {
 
 		Thread.sleep(Long.MAX_VALUE);
 	}
+
+	/**
+	 * indicates that Ha is started in zookeeper mode
+	 * @throws Exception
+	 */
+	public void startHAZookeeper() throws Exception {
+		String electPath = "/" + clientID + "/services";
+		String masterPath = "/" + clientID + "/leader";
+		CuratorUtils cu = new CuratorUtils();
+		cu.setZookeeperServer(zookeeperServer);
+		cu.setSessionTimeoutMs(sessionTimeoutMs);
+		cu.setConnectionTimeoutMs(connectionTimeoutMs);
+		cu.setMaxRetries(maxRetries);
+		cu.setBaseSleepTimeMs(baseSleepTimeMs);
+		cu.setClientId(clientID);
+		cu.setElectPath(electPath);
+		cu.setMasterPath(masterPath);
+		cu.init();
+		CuratorFramework client = cu.getClient();
+		LeaderLatch leader = new LeaderLatch(client, cu.getElectPath());
+		leader.start();
+		LOGGER.info("this node is participating in the election of the leader ....");
+		leader.addListener(new LeaderLatchListener() {
+			@Override
+			public void isLeader() {
+				try {
+					cu.register();
+				} catch (Exception e) {
+					e.printStackTrace();
+					LOGGER.error("The node registration is abnormal, check whether the maxwell host communicates properly with the zookeeper network");
+					cu.stop();
+					System.exit(1);
+				}
+				LOGGER.info("node is current leader, starting Maxwell....");
+				run();
+				cu.stop();
+			}
+
+			@Override
+			public void notLeader() {
+				//LeaderLatch.CloseMode.SILENT mode will not invoke this method
+			}
+		});
+
+		Thread.sleep(Long.MAX_VALUE);
+	}
+
 }