diff --git a/src/main/java/org/springframework/data/redis/connection/ReactiveHashCommands.java b/src/main/java/org/springframework/data/redis/connection/ReactiveHashCommands.java
index 267585d33..6d277f20e 100644
--- a/src/main/java/org/springframework/data/redis/connection/ReactiveHashCommands.java
+++ b/src/main/java/org/springframework/data/redis/connection/ReactiveHashCommands.java
@@ -582,10 +582,11 @@ public interface ReactiveHashCommands {
 
 	/**
 	 * Use a {@link Flux} to iterate over entries in the hash at {@code key}. The resulting {@link Flux} acts as a cursor
-	 * and issues {@code HSCAN} commands itself as long as the subscriber signals demand .
+	 * and issues {@code HSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return
+	 * @return the {@link Flux} emitting {@link java.util.Map.Entry entries} one by one.
+	 * @throws IllegalArgumentException in case the given key is {@literal null}.
 	 * @see <a href="http://redis.io/commands/hscan">Redis Documentation: HSCAN</a>
 	 * @since 2.1
 	 */
@@ -598,12 +599,14 @@ public interface ReactiveHashCommands {
 	 * {@link Flux} acts as a cursor and issues {@code HSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @param options must not be {@literal null}.
-	 * @return
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the raw {@link java.util.Map.Entry entries} one by one.
+	 * @throws IllegalArgumentException in case one of the required arguments is {@literal null}.
 	 * @see <a href="http://redis.io/commands/hscan">Redis Documentation: HSCAN</a>
 	 * @since 2.1
 	 */
 	default Flux<Map.Entry<ByteBuffer, ByteBuffer>> hScan(ByteBuffer key, ScanOptions options) {
+
 		return hScan(Mono.just(KeyScanCommand.key(key).withOptions(options))).map(CommandResponse::getOutput)
 				.flatMap(it -> it);
 	}
@@ -613,7 +616,7 @@ public interface ReactiveHashCommands {
 	 * and issues {@code HSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param commands must not be {@literal null}.
-	 * @return
+	 * @return the {@link Flux} emitting {@link CommandResponse} one by one.
 	 * @see <a href="http://redis.io/commands/hscan">Redis Documentation: HSCAN</a>
 	 * @since 2.1
 	 */
diff --git a/src/main/java/org/springframework/data/redis/connection/ReactiveKeyCommands.java b/src/main/java/org/springframework/data/redis/connection/ReactiveKeyCommands.java
index a69fa0f8e..7ec4a9549 100644
--- a/src/main/java/org/springframework/data/redis/connection/ReactiveKeyCommands.java
+++ b/src/main/java/org/springframework/data/redis/connection/ReactiveKeyCommands.java
@@ -112,7 +112,9 @@ public interface ReactiveKeyCommands {
 	Flux<NumericResponse<Collection<ByteBuffer>, Long>> touch(Publisher<Collection<ByteBuffer>> keys);
 
 	/**
-	 * Find all keys matching the given {@literal pattern}.
+	 * Find all keys matching the given {@literal pattern}.<br />
+	 * It is recommended to use {@link #scan(ScanOptions)} to iterate over the keyspace as {@link #keys(ByteBuffer)} is a
+	 * non-interruptible and expensive Redis operation.
 	 *
 	 * @param pattern must not be {@literal null}.
 	 * @return
@@ -126,8 +128,10 @@ public interface ReactiveKeyCommands {
 	}
 
 	/**
-	 * Find all keys matching the given {@literal pattern}.
-	 *
+	 * Find all keys matching the given {@literal pattern}.<br />
+	 * It is recommended to use {@link #scan(ScanOptions)} to iterate over the keyspace as {@link #keys(Publisher)} is a
+	 * non-interruptible and expensive Redis operation.
+	 * 
 	 * @param patterns must not be {@literal null}.
 	 * @return
 	 * @see <a href="http://redis.io/commands/keys">Redis Documentation: KEYS</a>
@@ -151,7 +155,8 @@ public interface ReactiveKeyCommands {
 	 * commands itself as long as the subscriber signals demand.
 	 *
 	 * @param options must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @return the {@link Flux} emitting {@link ByteBuffer keys} one by one.
+	 * @throws IllegalArgumentException when options is {@literal null}.
 	 * @see <a href="http://redis.io/commands/scan">Redis Documentation: SCAN</a>
 	 * @since 2.1
 	 */
diff --git a/src/main/java/org/springframework/data/redis/connection/ReactiveRedisConnection.java b/src/main/java/org/springframework/data/redis/connection/ReactiveRedisConnection.java
index eeb275950..5c6e28efc 100644
--- a/src/main/java/org/springframework/data/redis/connection/ReactiveRedisConnection.java
+++ b/src/main/java/org/springframework/data/redis/connection/ReactiveRedisConnection.java
@@ -211,14 +211,16 @@ public interface ReactiveRedisConnection extends Closeable {
 	}
 
 	/**
-	 * {@link Command} for key-bound scan operations like {@code HSCAN}, {@code SSCAN}, and {@code ZSCAN}, .
+	 * {@link Command} for key-bound scan operations like {@code SCAN}, {@code HSCAN}, {@code SSCAN} and {@code
+	 * ZSCAN}.
 	 *
 	 * @author Mark Paluch
+	 * @author Christoph Strobl
 	 * @since 2.1
 	 */
 	class KeyScanCommand extends KeyCommand {
 
-		private ScanOptions options;
+		private final ScanOptions options;
 
 		private KeyScanCommand(@Nullable ByteBuffer key, ScanOptions options) {
 
@@ -248,6 +250,11 @@ public interface ReactiveRedisConnection extends Closeable {
 			return new KeyScanCommand(getKey(), options);
 		}
 
+		/**
+		 * Get the {@link ScanOptions} to apply.
+		 *
+		 * @return never {@literal null}.
+		 */
 		public ScanOptions getOptions() {
 			return options;
 		}
diff --git a/src/main/java/org/springframework/data/redis/connection/ReactiveSetCommands.java b/src/main/java/org/springframework/data/redis/connection/ReactiveSetCommands.java
index bfc982c30..2e90ef49e 100644
--- a/src/main/java/org/springframework/data/redis/connection/ReactiveSetCommands.java
+++ b/src/main/java/org/springframework/data/redis/connection/ReactiveSetCommands.java
@@ -1020,7 +1020,8 @@ public interface ReactiveSetCommands {
 	 * and issues {@code SSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return
+	 * @return the {@link Flux} emitting the raw {@link ByteBuffer members} one by one.
+	 * @throws IllegalArgumentException when options is {@literal null}.
 	 * @see <a href="http://redis.io/commands/sscan">Redis Documentation: SSCAN</a>
 	 * @since 2.1
 	 */
@@ -1033,12 +1034,14 @@ public interface ReactiveSetCommands {
 	 * {@link Flux} acts as a cursor and issues {@code SSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @param options must not be {@literal null}.
-	 * @return
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the raw {@link ByteBuffer members} one by one.
+	 * @throws IllegalArgumentException when one of the required arguments is {@literal null}.
 	 * @see <a href="http://redis.io/commands/sscan">Redis Documentation: SSCAN</a>
 	 * @since 2.1
 	 */
 	default Flux<ByteBuffer> sScan(ByteBuffer key, ScanOptions options) {
+
 		return sScan(Mono.just(KeyScanCommand.key(key).withOptions(options))).map(CommandResponse::getOutput)
 				.flatMap(it -> it);
 	}
diff --git a/src/main/java/org/springframework/data/redis/connection/ReactiveZSetCommands.java b/src/main/java/org/springframework/data/redis/connection/ReactiveZSetCommands.java
index 8f2a5768b..4bf7a97ce 100644
--- a/src/main/java/org/springframework/data/redis/connection/ReactiveZSetCommands.java
+++ b/src/main/java/org/springframework/data/redis/connection/ReactiveZSetCommands.java
@@ -1004,7 +1004,8 @@ public interface ReactiveZSetCommands {
 	 * cursor and issues {@code ZSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return
+	 * @return the {@link Flux} emitting the raw {@link Tuple tuples} one by one.
+	 * @throws IllegalArgumentException when key is {@literal null}.
 	 * @see <a href="http://redis.io/commands/zscan">Redis Documentation: ZSCAN</a>
 	 * @since 2.1
 	 */
@@ -1017,12 +1018,14 @@ public interface ReactiveZSetCommands {
 	 * resulting {@link Flux} acts as a cursor and issues {@code ZSCAN} commands itself as long as the subscriber signals.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @param options must not be {@literal null}.
-	 * @return
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the raw {@link Tuple tuples} one by one.
+	 * @throws IllegalArgumentException when one of the required arguments is {@literal null}.
 	 * @see <a href="http://redis.io/commands/zscan">Redis Documentation: ZSCAN</a>
 	 * @since 2.1
 	 */
 	default Flux<Tuple> zScan(ByteBuffer key, ScanOptions options) {
+
 		return zScan(Mono.just(KeyScanCommand.key(key).withOptions(options))).map(CommandResponse::getOutput)
 				.flatMap(it -> it);
 	}
diff --git a/src/main/java/org/springframework/data/redis/connection/lettuce/LettuceReactiveHashCommands.java b/src/main/java/org/springframework/data/redis/connection/lettuce/LettuceReactiveHashCommands.java
index dd98592aa..fcaed56e3 100644
--- a/src/main/java/org/springframework/data/redis/connection/lettuce/LettuceReactiveHashCommands.java
+++ b/src/main/java/org/springframework/data/redis/connection/lettuce/LettuceReactiveHashCommands.java
@@ -75,8 +75,7 @@ class LettuceReactiveHashCommands implements ReactiveHashCommands {
 
 				Entry<ByteBuffer, ByteBuffer> entry = command.getFieldValueMap().entrySet().iterator().next();
 
-				result = command.isUpsert()
-						? cmd.hset(command.getKey(), entry.getKey(), entry.getValue())
+				result = command.isUpsert() ? cmd.hset(command.getKey(), entry.getKey(), entry.getValue())
 						: cmd.hsetnx(command.getKey(), entry.getKey(), entry.getValue());
 			} else {
 
@@ -246,7 +245,7 @@ class LettuceReactiveHashCommands implements ReactiveHashCommands {
 
 				@Override
 				public ByteBuffer setValue(ByteBuffer value) {
-					throw new UnsupportedOperationException("Cannot set value for entry in cursor");
+					throw new UnsupportedOperationException("Cannot set value for entry in cursor.");
 				}
 			});
 
diff --git a/src/main/java/org/springframework/data/redis/core/DefaultReactiveHashOperations.java b/src/main/java/org/springframework/data/redis/core/DefaultReactiveHashOperations.java
index 1d1e820fa..63b6244e1 100644
--- a/src/main/java/org/springframework/data/redis/core/DefaultReactiveHashOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/DefaultReactiveHashOperations.java
@@ -46,7 +46,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 	private final @NonNull ReactiveRedisTemplate<?, ?> template;
 	private final @NonNull RedisSerializationContext<H, ?> serializationContext;
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#delete(java.lang.Object, java.lang.Object[])
 	 */
 	@Override
@@ -64,7 +65,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.flatMap(hks -> connection.hDel(rawKey(key), hks)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#hasKey(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -77,7 +79,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 		return createMono(connection -> connection.hExists(rawKey(key), rawHashKey((HK) hashKey)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#get(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -90,7 +93,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 		return createMono(connection -> connection.hGet(rawKey(key), rawHashKey((HK) hashKey)).map(this::readHashValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#multiGet(java.lang.Object, java.util.Collection)
 	 */
 	@Override
@@ -106,7 +110,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.flatMap(hks -> connection.hMGet(rawKey(key), hks)).map(this::deserializeHashValues));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#increment(java.lang.Object, java.lang.Object, long)
 	 */
 	@Override
@@ -120,7 +125,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.hIncrBy(rawKey(key), rawHashKey(hashKey), delta));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#increment(java.lang.Object, java.lang.Object, double)
 	 */
 	@Override
@@ -134,7 +140,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.hIncrBy(rawKey(key), rawHashKey(hashKey), delta));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#keys(java.lang.Object)
 	 */
 	@Override
@@ -146,7 +153,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.map(this::readHashKey));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#size(java.lang.Object)
 	 */
 	@Override
@@ -157,7 +165,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 		return createMono(connection -> connection.hLen(rawKey(key)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#putAll(java.lang.Object, java.util.Map)
 	 */
 	@Override
@@ -171,7 +180,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.flatMap(serialized -> connection.hMSet(rawKey(key), serialized)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#put(java.lang.Object, java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -184,7 +194,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 		return createMono(connection -> connection.hSet(rawKey(key), rawHashKey(hashKey), rawHashValue(value)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#putIfAbsent(java.lang.Object, java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -197,7 +208,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 		return createMono(connection -> connection.hSetNX(rawKey(key), rawHashKey(hashKey), rawHashValue(value)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#values(java.lang.Object)
 	 */
 	@Override
@@ -209,7 +221,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.map(this::readHashValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#entries(java.lang.Object)
 	 */
 	@Override
@@ -221,7 +234,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.map(this::deserializeHashEntry));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#scan(java.lang.Object, org.springframework.data.redis.core.ScanOptions)
 	 */
 	@Override
@@ -234,7 +248,8 @@ class DefaultReactiveHashOperations<H, HK, HV> implements ReactiveHashOperations
 				.map(this::deserializeHashEntry));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveHashOperations#delete(java.lang.Object)
 	 */
 	@Override
diff --git a/src/main/java/org/springframework/data/redis/core/DefaultReactiveSetOperations.java b/src/main/java/org/springframework/data/redis/core/DefaultReactiveSetOperations.java
index f92f97e76..6f34e2ba3 100644
--- a/src/main/java/org/springframework/data/redis/core/DefaultReactiveSetOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/DefaultReactiveSetOperations.java
@@ -45,7 +45,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 	private final @NonNull ReactiveRedisTemplate<?, ?> template;
 	private final @NonNull RedisSerializationContext<K, V> serializationContext;
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#add(java.lang.Object, java.lang.Object[])
 	 */
 	@Override
@@ -63,7 +64,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.flatMap(serialized -> connection.sAdd(rawKey(key), serialized)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#remove(java.lang.Object, java.lang.Object[])
 	 */
 	@Override
@@ -82,7 +84,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.flatMap(serialized -> connection.sRem(rawKey(key), serialized)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#pop(java.lang.Object)
 	 */
 	@Override
@@ -105,7 +108,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createFlux(connection -> connection.sPop(rawKey(key), count).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#move(java.lang.Object, java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -117,7 +121,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createMono(connection -> connection.sMove(rawKey(sourceKey), rawKey(destKey), rawValue(value)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#size(java.lang.Object)
 	 */
 	@Override
@@ -128,7 +133,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createMono(connection -> connection.sCard(rawKey(key)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#isMember(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -140,7 +146,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createMono(connection -> connection.sIsMember(rawKey(key), rawValue((V) o)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#intersect(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -152,7 +159,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return intersect(key, Collections.singleton(otherKey));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#intersect(java.lang.Object, java.util.Collection)
 	 */
 	@Override
@@ -181,7 +189,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return intersectAndStore(key, Collections.singleton(otherKey), destKey);
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#intersectAndStore(java.lang.Object, java.util.Collection, java.lang.Object)
 	 */
 	@Override
@@ -197,7 +206,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.flatMap(rawKeys -> connection.sInterStore(rawKey(destKey), rawKeys)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#union(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -209,7 +219,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return union(key, Collections.singleton(otherKey));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#union(java.lang.Object, java.util.Collection)
 	 */
 	@Override
@@ -225,7 +236,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#unionAndStore(java.lang.Object, java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -238,7 +250,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return unionAndStore(key, Collections.singleton(otherKey), destKey);
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#unionAndStore(java.lang.Object, java.util.Collection, java.lang.Object)
 	 */
 	@Override
@@ -254,7 +267,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.flatMap(rawKeys -> connection.sUnionStore(rawKey(destKey), rawKeys)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#difference(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -266,7 +280,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return difference(key, Collections.singleton(otherKey));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#difference(java.lang.Object, java.util.Collection)
 	 */
 	@Override
@@ -282,7 +297,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#differenceAndStore(java.lang.Object, java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -295,7 +311,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return differenceAndStore(key, Collections.singleton(otherKey), destKey);
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#differenceAndStore(java.lang.Object, java.util.Collection, java.lang.Object)
 	 */
 	@Override
@@ -311,7 +328,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 				.flatMap(rawKeys -> connection.sDiffStore(rawKey(destKey), rawKeys)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#members(java.lang.Object)
 	 */
 	@Override
@@ -322,7 +340,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createFlux(connection -> connection.sMembers(rawKey(key)).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#scan(java.lang.Object, org.springframework.data.redis.core.ScanOptions)
 	 */
 	@Override
@@ -334,7 +353,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createFlux(connection -> connection.sScan(rawKey(key)).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#randomMember(java.lang.Object)
 	 */
 	@Override
@@ -345,7 +365,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createMono(connection -> connection.sRandMember(rawKey(key)).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#distinctRandomMembers(java.lang.Object, long)
 	 */
 	@Override
@@ -356,7 +377,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createFlux(connection -> connection.sRandMember(rawKey(key), count).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#randomMembers(java.lang.Object, long)
 	 */
 	@Override
@@ -367,7 +389,8 @@ class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V>
 		return createFlux(connection -> connection.sRandMember(rawKey(key), -count).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveSetOperations#delete(java.lang.Object)
 	 */
 	@Override
diff --git a/src/main/java/org/springframework/data/redis/core/DefaultReactiveZSetOperations.java b/src/main/java/org/springframework/data/redis/core/DefaultReactiveZSetOperations.java
index e7ae40882..1b9068d71 100644
--- a/src/main/java/org/springframework/data/redis/core/DefaultReactiveZSetOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/DefaultReactiveZSetOperations.java
@@ -53,7 +53,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 	private final @NonNull ReactiveRedisTemplate<?, ?> template;
 	private final @NonNull RedisSerializationContext<K, V> serializationContext;
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#add(java.lang.Object, java.lang.Object, double)
 	 */
 	@Override
@@ -64,7 +65,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zAdd(rawKey(key), score, rawValue(value)).map(l -> l != 0));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#add(java.lang.Object, java.util.Collection)
 	 */
 	@Override
@@ -79,7 +81,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 				.flatMap(serialized -> connection.zAdd(rawKey(key), serialized)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#remove(java.lang.Object, java.lang.Object[])
 	 */
 	@Override
@@ -99,7 +102,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 				.flatMap(serialized -> connection.zRem(rawKey(key), serialized)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#incrementScore(java.lang.Object, java.lang.Object, double)
 	 */
 	@Override
@@ -110,7 +114,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zIncrBy(rawKey(key), delta, rawValue(value)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rank(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -122,7 +127,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zRank(rawKey(key), rawValue((V) o)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRank(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -134,7 +140,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zRevRank(rawKey(key), rawValue((V) o)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#range(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -146,7 +153,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRange(rawKey(key), range).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeWithScores(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -158,7 +166,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRangeWithScores(rawKey(key), range).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeByScore(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -170,7 +179,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRangeByScore(rawKey(key), range).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeByScoreWithScores(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -182,7 +192,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRangeByScoreWithScores(rawKey(key), range).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeByScore(java.lang.Object, org.springframework.data.domain.Range, org.springframework.data.redis.connection.RedisZSetCommands.Limit)
 	 */
 	@Override
@@ -194,7 +205,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRangeByScore(rawKey(key), range, limit).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeByScoreWithScores(java.lang.Object, org.springframework.data.domain.Range, org.springframework.data.redis.connection.RedisZSetCommands.Limit)
 	 */
 	@Override
@@ -208,7 +220,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 				connection -> connection.zRangeByScoreWithScores(rawKey(key), range, limit).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRange(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -220,7 +233,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRevRange(rawKey(key), range).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeWithScores(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -232,7 +246,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRevRangeWithScores(rawKey(key), range).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeByScore(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -244,7 +259,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRevRangeByScore(rawKey(key), range).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeByScoreWithScores(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -257,7 +273,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 				connection -> connection.zRevRangeByScoreWithScores(rawKey(key), range).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeByScore(java.lang.Object, org.springframework.data.domain.Range, org.springframework.data.redis.connection.RedisZSetCommands.Limit)
 	 */
 	@Override
@@ -269,7 +286,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRevRangeByScore(rawKey(key), range, limit).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeByScoreWithScores(java.lang.Object, org.springframework.data.domain.Range, org.springframework.data.redis.connection.RedisZSetCommands.Limit)
 	 */
 	@Override
@@ -283,7 +301,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 				connection -> connection.zRevRangeByScoreWithScores(rawKey(key), range, limit).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#scan(java.lang.Object, org.springframework.data.redis.core.ScanOptions)
 	 */
 	@Override
@@ -295,7 +314,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zScan(rawKey(key), options).map(this::readTypedTuple));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#count(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -307,7 +327,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zCount(rawKey(key), range));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#size(java.lang.Object)
 	 */
 	@Override
@@ -318,7 +339,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zCard(rawKey(key)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#score(java.lang.Object, java.lang.Object)
 	 */
 	@Override
@@ -330,7 +352,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zScore(rawKey(key), rawValue((V) o)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#removeRange(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -342,7 +365,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createMono(connection -> connection.zRemRangeByRank(rawKey(key), range));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#removeRangeByScore(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -454,7 +478,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 				.flatMap(serialized -> connection.zInterStore(rawKey(destKey), serialized, weights, aggregate)));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeByLex(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -466,7 +491,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRangeByLex(rawKey(key), range).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#rangeByLex(java.lang.Object, org.springframework.data.domain.Range, org.springframework.data.redis.connection.RedisZSetCommands.Limit)
 	 */
 	@Override
@@ -479,7 +505,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRangeByLex(rawKey(key), range, limit).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeByLex(java.lang.Object, org.springframework.data.domain.Range)
 	 */
 	@Override
@@ -491,7 +518,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRevRangeByLex(rawKey(key), range).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#reverseRangeByLex(java.lang.Object, org.springframework.data.domain.Range, org.springframework.data.redis.connection.RedisZSetCommands.Limit)
 	 */
 	@Override
@@ -504,7 +532,8 @@ class DefaultReactiveZSetOperations<K, V> implements ReactiveZSetOperations<K, V
 		return createFlux(connection -> connection.zRevRangeByLex(rawKey(key), range, limit).map(this::readValue));
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.core.ReactiveZSetOperations#delete(java.lang.Object)
 	 */
 	@Override
diff --git a/src/main/java/org/springframework/data/redis/core/ReactiveHashOperations.java b/src/main/java/org/springframework/data/redis/core/ReactiveHashOperations.java
index b3cd3df50..a0f57d5b6 100644
--- a/src/main/java/org/springframework/data/redis/core/ReactiveHashOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/ReactiveHashOperations.java
@@ -147,11 +147,13 @@ public interface ReactiveHashOperations<H, HK, HV> {
 	Flux<Map.Entry<HK, HV>> entries(H key);
 
 	/**
-	 * Use a {@link Flux} to iterate over entries in the hash at {@code key} given {@link ScanOptions}. The resulting
-	 * {@link Flux} acts as a cursor and issues {@code HSCAN} commands itself as long as the subscriber signals demand.
+	 * Use a {@link Flux} to iterate over entries in the hash at {@code key}. The resulting {@link Flux} acts as a cursor
+	 * and issues {@code HSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @return the {@link Flux} emitting the {@link java.util.Map.Entry entries} on by one or an {@link Flux#empty() empty
+	 *         flux} if the key does not exist.
+	 * @throws IllegalArgumentException when the given {@code key} is {@literal null}.
 	 * @see <a href="http://redis.io/commands/hscan">Redis Documentation: HSCAN</a>
 	 * @since 2.1
 	 */
@@ -164,8 +166,10 @@ public interface ReactiveHashOperations<H, HK, HV> {
 	 * {@link Flux} acts as a cursor and issues {@code HSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @param options must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the {@link java.util.Map.Entry entries} on by one or an {@link Flux#empty() empty
+	 *         flux} if the key does not exist.
+	 * @throws IllegalArgumentException when one of the required arguments is {@literal null}.
 	 * @see <a href="http://redis.io/commands/hscan">Redis Documentation: HSCAN</a>
 	 * @since 2.1
 	 */
diff --git a/src/main/java/org/springframework/data/redis/core/ReactiveRedisOperations.java b/src/main/java/org/springframework/data/redis/core/ReactiveRedisOperations.java
index ab8c97702..4d407bc8b 100644
--- a/src/main/java/org/springframework/data/redis/core/ReactiveRedisOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/ReactiveRedisOperations.java
@@ -138,22 +138,24 @@ public interface ReactiveRedisOperations<K, V> {
 	Mono<DataType> type(K key);
 
 	/**
-	 * Find all keys matching the given {@code pattern}.
+	 * Find all keys matching the given {@code pattern}. <br />
+	 * <strong>IMPORTANT:</strong> It is recommended to use {@link #scan()} to iterate over the keyspace as
+	 * {@link #keys(Object)} is a
+	 * non-interruptible and expensive Redis operation.
 	 *
 	 * @param pattern must not be {@literal null}.
-	 * @return
+	 * @return the {@link Flux} emitting matching keys one by one.
+	 * @throws IllegalArgumentException in case the pattern is {@literal null}.
 	 * @see <a href="http://redis.io/commands/keys">Redis Documentation: KEYS</a>
-	 * @deprecated Since 2.1. Use {@link #scan()} to iterate over the keyspace as {@link #keys(Object)} is a
-	 *             non-interruptible and expensive Redis operation.
 	 */
-	@Deprecated
 	Flux<K> keys(K pattern);
 
 	/**
 	 * Use a {@link Flux} to iterate over keys. The resulting {@link Flux} acts as a cursor and issues {@code SCAN}
 	 * commands itself as long as the subscriber signals demand.
 	 *
-	 * @return never {@literal null}.
+	 * @return the {@link Flux} emitting the {@literal keys} one by one or an {@link Flux#empty() empty flux} if none
+	 *         exist.
 	 * @see <a href="http://redis.io/commands/scan">Redis Documentation: SCAN</a>
 	 * @since 2.1
 	 */
@@ -165,8 +167,10 @@ public interface ReactiveRedisOperations<K, V> {
 	 * Use a {@link Flux} to iterate over keys. The resulting {@link Flux} acts as a cursor and issues {@code SCAN}
 	 * commands itself as long as the subscriber signals demand.
 	 *
-	 * @param options must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the {@literal keys} one by one or an {@link Flux#empty() empty flux} if none
+	 *         exist.
+	 * @throws IllegalArgumentException when the given {@code options} is {@literal null}.
 	 * @see <a href="http://redis.io/commands/scan">Redis Documentation: SCAN</a>
 	 * @since 2.1
 	 */
diff --git a/src/main/java/org/springframework/data/redis/core/ReactiveSetOperations.java b/src/main/java/org/springframework/data/redis/core/ReactiveSetOperations.java
index 8ab9d5923..f9864e04c 100644
--- a/src/main/java/org/springframework/data/redis/core/ReactiveSetOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/ReactiveSetOperations.java
@@ -235,11 +235,13 @@ public interface ReactiveSetOperations<K, V> {
 	Flux<V> members(K key);
 
 	/**
-	 * Use a {@link Flux} to iterate over entries in the set at {@code key} given {@link ScanOptions}. The resulting
-	 * {@link Flux} acts as a cursor and issues {@code SSCAN} commands itself as long as the subscriber signals demand.
+	 * Use a {@link Flux} to iterate over entries in the set at {@code key}. The resulting {@link Flux} acts as a cursor
+	 * and issues {@code SSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @return the {@link Flux} emitting the {@literal values} one by one or an {@link Flux#empty() empty Flux} if none
+	 *         exist.
+	 * @throws IllegalArgumentException when given {@code key} is {@literal null}.
 	 * @see <a href="http://redis.io/commands/sscan">Redis Documentation: SSCAN</a>
 	 * @since 2.1
 	 */
@@ -252,8 +254,10 @@ public interface ReactiveSetOperations<K, V> {
 	 * {@link Flux} acts as a cursor and issues {@code SSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @param options must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the {@literal values} one by one or an {@link Flux#empty() empty Flux} if the key
+	 *         does not exist.
+	 * @throws IllegalArgumentException when one of the required arguments is {@literal null}.
 	 * @see <a href="http://redis.io/commands/sscan">Redis Documentation: SSCAN</a>
 	 * @since 2.1
 	 */
diff --git a/src/main/java/org/springframework/data/redis/core/ReactiveZSetOperations.java b/src/main/java/org/springframework/data/redis/core/ReactiveZSetOperations.java
index 33092e4df..0af3d4201 100644
--- a/src/main/java/org/springframework/data/redis/core/ReactiveZSetOperations.java
+++ b/src/main/java/org/springframework/data/redis/core/ReactiveZSetOperations.java
@@ -229,12 +229,13 @@ public interface ReactiveZSetOperations<K, V> {
 	Flux<TypedTuple<V>> reverseRangeByScoreWithScores(K key, Range<Double> range, Limit limit);
 
 	/**
-	 * Use a {@link Flux} to iterate over entries in the sorted set at {@code key} given {@link ScanOptions}. The
-	 * resulting {@link Flux} acts as a cursor and issues {@code ZSCAN} commands itself as long as the subscriber signals
-	 * demand.
+	 * Use a {@link Flux} to iterate over entries in the sorted set at {@code key}. The resulting {@link Flux} acts as a
+	 * cursor and issues {@code ZSCAN} commands itself as long as the subscriber signals demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @return the {@link Flux} emitting the {@literal values} one by one or an {@link Flux#empty() empty Flux} if none
+	 *         exist.
+	 * @throws IllegalArgumentException when given {@code key} is {@literal null}.
 	 * @see <a href="http://redis.io/commands/zscan">Redis Documentation: ZSCAN</a>
 	 * @since 2.1
 	 */
@@ -248,8 +249,10 @@ public interface ReactiveZSetOperations<K, V> {
 	 * demand.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @param options must not be {@literal null}.
-	 * @return never {@literal null}.
+	 * @param options must not be {@literal null}. Use {@link ScanOptions#NONE} instead.
+	 * @return the {@link Flux} emitting the {@literal values} one by one or an {@link Flux#empty() empty Flux} if none
+	 *         exist.
+	 * @throws IllegalArgumentException when one of the required arguments is {@literal null}.
 	 * @see <a href="http://redis.io/commands/zscan">Redis Documentation: ZSCAN</a>
 	 * @since 2.1
 	 */