DATAREDIS-324 - Add Redis Sentinel support.

We’ve added RedisSentinelConfiguration holding required information for connecting to redis sentinels. This can be used to set up ConnectionFeactory for HA environments.

**Using Jedis**
Providing RedisSentinelConfiguration will force the JedisConnectionFactory to use JedisSentinelPool for managing resources.

**Using Lettuce/JRedis/SRP**
There’s currently no support for sentinel in those clients.

**CI Build**
We’ve added makefile to build and set up redis instances for testing sentinel support on travis-ci. There’s already a section for redis cluster.
The cluster section is for whatever reason currently not working as the cluster nodes won’t start.
This will be fixed when we add redis-cluster support.

_side note:_ there’s an alternative fork of lettuce at mp911de/lettuce that already has sentinel support.

src/main/java/org/springframework/data/redis/connection/NamedNode.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.connection;
+
+/**
+ * @author Christoph Strobl
+ * @since 1.4
+ */
+public interface NamedNode {
+
+	String getName();
+}

src/main/java/org/springframework/data/redis/connection/RedisNode.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.connection;
+
+import org.springframework.util.ObjectUtils;
+
+/**
+ * @author Christoph Strobl
+ * @since 1.4
+ */
+public class RedisNode {
+
+	private final String host;
+	private final int port;
+
+	public RedisNode(String host, int port) {
+		this.host = host;
+		this.port = port;
+	}
+
+	public String getHost() {
+		return host;
+	}
+
+	public Integer getPort() {
+		return port;
+	}
+
+	public String asString() {
+		return host + ":" + port;
+	}
+
+	@Override
+	public String toString() {
+		return asString();
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ObjectUtils.nullSafeHashCode(host);
+		result = prime * result + ObjectUtils.nullSafeHashCode(port);
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+
+		if (this == obj) {
+			return true;
+		}
+		if (obj == null || !(obj instanceof RedisNode)) {
+			return false;
+		}
+
+		RedisNode other = (RedisNode) obj;
+
+		if (!ObjectUtils.nullSafeEquals(this.host, other.host)) {
+			return false;
+		}
+
+		if (!ObjectUtils.nullSafeEquals(this.port, other.port)) {
+			return false;
+		}
+
+		return true;
+	}
+
+}

src/main/java/org/springframework/data/redis/connection/RedisSentinelConfiguration.java

@@ -0,0 +1,154 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.connection;
+
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.springframework.util.Assert;
+
+/**
+ * Configuration class used for setting up {@link RedisConnection} via {@link RedisConnectionFactory} using connecting
+ * to <a href="http://redis.io/topics/sentinel">Redis Sentinel(s)</a>. Useful when setting up a high availability Redis
+ * environment.
+ * 
+ * @author Christoph Strobl
+ * @since 1.4
+ */
+public class RedisSentinelConfiguration {
+
+	private NamedNode master;
+	private Set<RedisNode> sentinels;
+
+	/**
+	 * Creates new {@link RedisSentinelConfiguration}.
+	 */
+	public RedisSentinelConfiguration() {
+		this.sentinels = new LinkedHashSet<RedisNode>();
+	}
+
+	/**
+	 * Set {@literal Sentinels} to connect to.
+	 * 
+	 * @param sentinels must not be {@literal null}.
+	 */
+	public void setSentinels(Iterable<RedisNode> sentinels) {
+
+		Assert.notNull(sentinels, "Cannot set sentinels to 'null'.");
+		this.sentinels.clear();
+		for (RedisNode sentinel : sentinels) {
+			addSentinel(sentinel);
+		}
+	}
+
+	/**
+	 * Returns an {@link Collections#unmodifiableSet(Set)} of {@literal Sentinels}.
+	 * 
+	 * @return {@link Set} of sentinels. Never {@literal null}.
+	 */
+	public Set<RedisNode> getSentinels() {
+		return Collections.unmodifiableSet(sentinels);
+	}
+
+	/**
+	 * Add sentinel.
+	 * 
+	 * @param sentinel must not be {@literal null}.
+	 */
+	public void addSentinel(RedisNode sentinel) {
+
+		Assert.notNull(sentinel, "Sentinel must not be 'null'.");
+		this.sentinels.add(sentinel);
+	}
+
+	/**
+	 * Set the master node via its name.
+	 * 
+	 * @param name must not be {@literal null}.
+	 */
+	public void setMaster(final String name) {
+
+		Assert.notNull(name, "Name of sentinel master must not be null.");
+		setMaster(new NamedNode() {
+
+			@Override
+			public String getName() {
+				return name;
+			}
+		});
+	}
+
+	/**
+	 * Set the master.
+	 * 
+	 * @param master must not be {@literal null}.
+	 */
+	public void setMaster(NamedNode master) {
+
+		Assert.notNull("Sentinel master node must not be 'null'.");
+		this.master = master;
+	}
+
+	/**
+	 * Get the {@literal Sentinel} master node.
+	 * 
+	 * @return
+	 */
+	public NamedNode getMaster() {
+		return master;
+	}
+
+	/**
+	 * @see #setMaster(String)
+	 * @param master
+	 * @return
+	 */
+	public RedisSentinelConfiguration master(String master) {
+		this.setMaster(master);
+		return this;
+	}
+
+	/**
+	 * @see #setMaster(NamedNode)
+	 * @param master
+	 * @return
+	 */
+	public RedisSentinelConfiguration master(NamedNode master) {
+		this.setMaster(master);
+		return this;
+	}
+
+	/**
+	 * @see #addSentinel(RedisNode)
+	 * @param sentinel
+	 * @return
+	 */
+	public RedisSentinelConfiguration sentinel(RedisNode sentinel) {
+		this.addSentinel(sentinel);
+		return this;
+	}
+
+	/**
+	 * @see #sentinel(RedisNode)
+	 * @param host
+	 * @param port
+	 * @return
+	 */
+	public RedisSentinelConfiguration sentinel(String host, Integer port) {
+		return sentinel(new RedisNode(host, port));
+	}
+}

src/main/java/org/springframework/data/redis/connection/jedis/JedisConnectionFactory.java

@@ -16,6 +16,11 @@
 
 package org.springframework.data.redis.connection.jedis;
 
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.factory.DisposableBean;
@@ -26,20 +31,26 @@ import org.springframework.data.redis.PassThroughExceptionTranslationStrategy;
 import org.springframework.data.redis.RedisConnectionFailureException;
 import org.springframework.data.redis.connection.RedisConnection;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.connection.RedisNode;
+import org.springframework.data.redis.connection.RedisSentinelConfiguration;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 
 import redis.clients.jedis.Jedis;
 import redis.clients.jedis.JedisPool;
 import redis.clients.jedis.JedisPoolConfig;
+import redis.clients.jedis.JedisSentinelPool;
 import redis.clients.jedis.JedisShardInfo;
 import redis.clients.jedis.Protocol;
+import redis.clients.util.Pool;
 
 /**
  * Connection factory creating <a href="http://github.com/xetorthio/jedis">Jedis</a> based connections.
  * 
  * @author Costin Leau
  * @author Thomas Darimont
+ * @author Christoph Strobl
  */
 public class JedisConnectionFactory implements InitializingBean, DisposableBean, RedisConnectionFactory {
 
@@ -53,10 +64,11 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 	private int timeout = Protocol.DEFAULT_TIMEOUT;
 	private String password;
 	private boolean usePool = true;
-	private JedisPool pool = null;
+	private Pool<Jedis> pool;
 	private JedisPoolConfig poolConfig = new JedisPoolConfig();
 	private int dbIndex = 0;
 	private boolean convertPipelineAndTxResults = true;
+	private RedisSentinelConfiguration sentinelConfig;
 
 	/**
 	 * Constructs a new <code>JedisConnectionFactory</code> instance with default settings (default connection pooling, no
@@ -80,7 +92,31 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 	 * @param poolConfig pool configuration
 	 */
 	public JedisConnectionFactory(JedisPoolConfig poolConfig) {
-		this.poolConfig = poolConfig;
+		this(null, poolConfig);
+	}
+
+	/**
+	 * Constructs a new {@link JedisConnectionFactory} instance using the given {@link JedisPoolConfig} applied to
+	 * {@link JedisSentinelPool}.
+	 * 
+	 * @param sentinelConfig
+	 * @since 1.4
+	 */
+	public JedisConnectionFactory(RedisSentinelConfiguration sentinelConfig) {
+		this(sentinelConfig, null);
+	}
+
+	/**
+	 * Constructs a new {@link JedisConnectionFactory} instance using the given {@link JedisPoolConfig} applied to
+	 * {@link JedisSentinelPool}.
+	 * 
+	 * @param sentinelConfig
+	 * @param poolConfig pool configuration. Defaulted to new instance if {@literal null}.
+	 * @since 1.4
+	 */
+	public JedisConnectionFactory(RedisSentinelConfiguration sentinelConfig, JedisPoolConfig poolConfig) {
+		this.sentinelConfig = sentinelConfig;
+		this.poolConfig = poolConfig != null ? poolConfig : new JedisPoolConfig();
 	}
 
 	/**
@@ -114,6 +150,10 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 		return connection;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
+	 */
 	public void afterPropertiesSet() {
 		if (shardInfo == null) {
 			shardInfo = new JedisShardInfo(hostName, port);
@@ -128,11 +168,46 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 		}
 
 		if (usePool) {
-			pool = new JedisPool(poolConfig, shardInfo.getHost(), shardInfo.getPort(), shardInfo.getTimeout(),
-					shardInfo.getPassword());
+			this.pool = createPool();
 		}
 	}
 
+	private Pool<Jedis> createPool() {
+
+		if (isRedisSentinelAware()) {
+			return createRedisSentinelPool(this.sentinelConfig);
+		}
+		return createRedisPool();
+	}
+
+	/**
+	 * Creates {@link JedisSentinelPool}.
+	 * 
+	 * @param config
+	 * @return
+	 * @since 1.4
+	 */
+	protected Pool<Jedis> createRedisSentinelPool(RedisSentinelConfiguration config) {
+		return new JedisSentinelPool(config.getMaster().getName(), convertToJedisSentinelSet(config.getSentinels()),
+				getPoolConfig() != null ? getPoolConfig() : new JedisPoolConfig(), getShardInfo().getTimeout(), getShardInfo()
+						.getPassword());
+	}
+
+	/**
+	 * Creates {@link JedisPool}.
+	 * 
+	 * @return
+	 * @since 1.4
+	 */
+	protected Pool<Jedis> createRedisPool() {
+		return new JedisPool(getPoolConfig(), getShardInfo().getHost(), getShardInfo().getPort(), getShardInfo()
+				.getTimeout(), getShardInfo().getPassword());
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.beans.factory.DisposableBean#destroy()
+	 */
 	public void destroy() {
 		if (usePool && pool != null) {
 			try {
@@ -144,6 +219,10 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 		}
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.connection.RedisConnectionFactory#getConnection()
+	 */
 	public JedisConnection getConnection() {
 		Jedis jedis = fetchJedisConnector();
 		JedisConnection connection = (usePool ? new JedisConnection(jedis, pool, dbIndex) : new JedisConnection(jedis,
@@ -152,6 +231,10 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 		return postProcessConnection(connection);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.dao.support.PersistenceExceptionTranslator#translateExceptionIfPossible(java.lang.RuntimeException)
+	 */
 	public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
 		return EXCEPTION_TRANSLATION.translate(ex);
 	}
@@ -321,4 +404,28 @@ public class JedisConnectionFactory implements InitializingBean, DisposableBean,
 	public void setConvertPipelineAndTxResults(boolean convertPipelineAndTxResults) {
 		this.convertPipelineAndTxResults = convertPipelineAndTxResults;
 	}
+
+	/**
+	 * @return true when {@link RedisSentinelConfiguration} is present.
+	 * @since 1.4
+	 */
+	public boolean isRedisSentinelAware() {
+		return sentinelConfig != null;
+	}
+
+	private Set<String> convertToJedisSentinelSet(Collection<RedisNode> nodes) {
+
+		if (CollectionUtils.isEmpty(nodes)) {
+			return Collections.emptySet();
+		}
+
+		Set<String> convertedNodes = new LinkedHashSet<String>(nodes.size());
+		for (RedisNode node : nodes) {
+			if (node != null) {
+				convertedNodes.add(node.asString());
+			}
+		}
+		return convertedNodes;
+	}
+
 }