The KEYS command needs to be keyless

src/main/java/io/lettuce/core/AbstractRedisAsyncCommands.java

@@ -2095,15 +2095,43 @@ public RedisFuture<Map<V, VSimScoreAttribs>> vsimWithScoreWithAttribs(K key, VSi
     }
 
     @Override
-    public RedisFuture<List<K>> keys(K pattern) {
+    public RedisFuture<List<String>> keys(String pattern) {
         return dispatch(commandBuilder.keys(pattern));
     }
 
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
+     * @return List&lt;K&gt; array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
+     */
+    @Deprecated
+    @Override
+    public RedisFuture<List<K>> keysLegacy(K pattern) {
+        return dispatch(commandBuilder.keysLegacy(pattern));
+    }
+
     @Override
-    public RedisFuture<Long> keys(KeyStreamingChannel<K> channel, K pattern) {
+    public RedisFuture<Long> keys(KeyStreamingChannel<String> channel, String pattern) {
         return dispatch(commandBuilder.keys(channel, pattern));
     }
 
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
+     */
+    @Deprecated
+    @Override
+    public RedisFuture<Long> keysLegacy(KeyStreamingChannel<K> channel, K pattern) {
+        return dispatch(commandBuilder.keysLegacy(channel, pattern));
+    }
+
     @Override
     public RedisFuture<Date> lastsave() {
         return dispatch(commandBuilder.lastsave());

src/main/java/io/lettuce/core/AbstractRedisReactiveCommands.java

@@ -2160,15 +2160,43 @@ public Mono<Map<V, VSimScoreAttribs>> vsimWithScoreWithAttribs(K key, VSimArgs a
     }
 
     @Override
-    public Flux<K> keys(K pattern) {
+    public Flux<String> keys(String pattern) {
         return createDissolvingFlux(() -> commandBuilder.keys(pattern));
     }
 
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
+     * @return K array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
+     */
+    @Deprecated
+    @Override
+    public Flux<K> keysLegacy(K pattern) {
+        return createDissolvingFlux(() -> commandBuilder.keysLegacy(pattern));
+    }
+
     @Override
-    public Mono<Long> keys(KeyStreamingChannel<K> channel, K pattern) {
+    public Mono<Long> keys(KeyStreamingChannel<String> channel, String pattern) {
         return createMono(() -> commandBuilder.keys(channel, pattern));
     }
 
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
+     */
+    @Deprecated
+    @Override
+    public Mono<Long> keysLegacy(KeyStreamingChannel<K> channel, K pattern) {
+        return createMono(() -> commandBuilder.keysLegacy(channel, pattern));
+    }
+
     @Override
     public Mono<Date> lastsave() {
         return createMono(commandBuilder::lastsave);

src/main/java/io/lettuce/core/RedisCommandBuilder.java

@@ -1942,17 +1942,52 @@ Command<K, V, String> info(String section) {
         return createCommand(CommandType.INFO, new StatusOutput<>(codec), args);
     }
 
-    Command<K, V, List<K>> keys(K pattern) {
+    Command<K, V, List<String>> keys(String pattern) {
         LettuceAssert.notNull(pattern, "Pattern " + MUST_NOT_BE_NULL);
 
-        return createCommand(KEYS, new KeyListOutput<>(codec), pattern);
+        CommandArgs<K, V> args = new CommandArgs<>(codec).add(pattern);
+        return createCommand(KEYS, new StringListOutput<>(codec), args);
     }
 
-    Command<K, V, Long> keys(KeyStreamingChannel<K> channel, K pattern) {
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
+     * @return List&lt;K&gt; array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
+     */
+    @Deprecated
+    Command<K, V, List<K>> keysLegacy(K pattern) {
+        LettuceAssert.notNull(pattern, "Pattern " + MUST_NOT_BE_NULL);
+
+        CommandArgs<K, V> args = new CommandArgs<>(codec).addKey(pattern);
+        return createCommand(KEYS, new KeyListOutput<>(codec), args);
+    }
+
+    Command<K, V, Long> keys(KeyStreamingChannel<String> channel, String pattern) {
+        LettuceAssert.notNull(pattern, "Pattern " + MUST_NOT_BE_NULL);
+        notNull(channel);
+
+        CommandArgs<K, V> args = new CommandArgs<>(codec).add(pattern);
+        return createCommand(KEYS, new StringStreamingOutput<>(codec, channel), args);
+    }
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
+     */
+    @Deprecated
+    Command<K, V, Long> keysLegacy(KeyStreamingChannel<K> channel, K pattern) {
         LettuceAssert.notNull(pattern, "Pattern " + MUST_NOT_BE_NULL);
         notNull(channel);
 
-        return createCommand(KEYS, new KeyStreamingOutput<>(codec, channel), pattern);
+        CommandArgs<K, V> args = new CommandArgs<>(codec).addKey(pattern);
+        return createCommand(KEYS, new KeyStreamingOutput<>(codec, channel), args);
     }
 
     Command<K, V, Date> lastsave() {

src/main/java/io/lettuce/core/api/async/RedisKeyAsyncCommands.java

@@ -218,18 +218,43 @@ public interface RedisKeyAsyncCommands<K, V> {
      * Find all keys matching the given pattern.
      *
      * @param pattern the pattern type: patternkey (pattern).
+     * @return List&lt;String&gt; array-reply list of keys matching {@code pattern}.
+     * @implNote {@code keysLegacy(K)} is deprecated and will be removed in a later version. Prefer {@link #keys(String)}.
+     */
+    RedisFuture<List<String>> keys(String pattern);
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
      * @return List&lt;K&gt; array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
      */
-    RedisFuture<List<K>> keys(K pattern);
+    @Deprecated
+    RedisFuture<List<K>> keysLegacy(K pattern);
 
     /**
      * Find all keys matching the given pattern.
      *
      * @param channel the channel.
      * @param pattern the pattern.
      * @return Long array-reply list of keys matching {@code pattern}.
+     * @implNote {@code keysLegacy(KeyStreamingChannel, K)} is deprecated and will be removed in a later version. Prefer
+     *           {@link #keys(KeyStreamingChannel, String)}.
+     */
+    RedisFuture<Long> keys(KeyStreamingChannel<String> channel, String pattern);
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
      */
-    RedisFuture<Long> keys(KeyStreamingChannel<K> channel, K pattern);
+    @Deprecated
+    RedisFuture<Long> keysLegacy(KeyStreamingChannel<K> channel, K pattern);
 
     /**
      * Atomically transfer a key from a Redis instance to another one.

src/main/java/io/lettuce/core/api/reactive/RedisKeyReactiveCommands.java

@@ -228,21 +228,48 @@ public interface RedisKeyReactiveCommands<K, V> {
      * Find all keys matching the given pattern.
      *
      * @param pattern the pattern type: patternkey (pattern).
+     * @return String array-reply list of keys matching {@code pattern}.
+     * @implNote {@code keysLegacy(K)} is deprecated and will be removed in a later version. Prefer {@link #keys(String)}.
+     */
+    Flux<String> keys(String pattern);
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
      * @return K array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
      */
-    Flux<K> keys(K pattern);
+    @Deprecated
+    Flux<K> keysLegacy(K pattern);
 
     /**
      * Find all keys matching the given pattern.
      *
      * @param channel the channel.
      * @param pattern the pattern.
      * @return Long array-reply list of keys matching {@code pattern}.
+     * @implNote {@code keysLegacy(KeyStreamingChannel, K)} is deprecated and will be removed in a later version. Prefer
+     *           {@link #keys(KeyStreamingChannel, String)}.
      * @deprecated since 6.0 in favor of consuming large results through the {@link org.reactivestreams.Publisher} returned by
      *             {@link #keys}.
      */
     @Deprecated
-    Mono<Long> keys(KeyStreamingChannel<K> channel, K pattern);
+    Mono<Long> keys(KeyStreamingChannel<String> channel, String pattern);
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
+     * @deprecated since 6.0 in favor of consuming large results through the {@link org.reactivestreams.Publisher} returned by
+     *             {@link #keysLegacy}.
+     */
+    @Deprecated
+    Mono<Long> keysLegacy(KeyStreamingChannel<K> channel, K pattern);
 
     /**
      * Atomically transfer a key from a Redis instance to another one.

src/main/java/io/lettuce/core/api/sync/RedisKeyCommands.java

@@ -227,18 +227,43 @@ public interface RedisKeyCommands<K, V> {
      * Find all keys matching the given pattern.
      *
      * @param pattern the pattern type: patternkey (pattern).
+     * @return List&lt;String&gt; array-reply list of keys matching {@code pattern}.
+     * @implNote {@code keysLegacy(K)} is deprecated and will be removed in a later version. Prefer {@link #keys(String)}.
+     */
+    List<String> keys(String pattern);
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
      * @return List&lt;K&gt; array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
      */
-    List<K> keys(K pattern);
+    @Deprecated
+    List<K> keysLegacy(K pattern);
 
     /**
      * Find all keys matching the given pattern.
      *
      * @param channel the channel.
      * @param pattern the pattern.
      * @return Long array-reply list of keys matching {@code pattern}.
+     * @implNote {@code keysLegacy(KeyStreamingChannel, K)} is deprecated and will be removed in a later version. Prefer
+     *           {@link #keys(KeyStreamingChannel, String)}.
+     */
+    Long keys(KeyStreamingChannel<String> channel, String pattern);
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
      */
-    Long keys(KeyStreamingChannel<K> channel, K pattern);
+    @Deprecated
+    Long keysLegacy(KeyStreamingChannel<K> channel, K pattern);
 
     /**
      * Atomically transfer a key from a Redis instance to another one.

src/main/java/io/lettuce/core/cluster/RedisAdvancedClusterAsyncCommandsImpl.java

@@ -276,9 +276,31 @@ public RedisFuture<String> flushdb(FlushMode flushMode) {
     }
 
     @Override
-    public RedisFuture<List<K>> keys(K pattern) {
+    public RedisFuture<List<String>> keys(String pattern) {
 
-        Map<String, CompletableFuture<List<K>>> executions = executeOnUpstream(commands -> commands.keys(pattern));
+        Map<String, CompletableFuture<List<String>>> executions = executeOnUpstream(commands -> commands.keys(pattern));
+
+        return new PipelinedRedisFuture<>(executions, objectPipelinedRedisFuture -> {
+            List<String> result = new ArrayList<>();
+            for (CompletableFuture<List<String>> future : executions.values()) {
+                result.addAll(MultiNodeExecution.execute(future::get));
+            }
+            return result;
+        });
+    }
+
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param pattern the pattern type: patternkey (pattern).
+     * @return List&lt;K&gt; array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(String)} instead. This legacy overload will be removed in a later version.
+     */
+    @Deprecated
+    @Override
+    public RedisFuture<List<K>> keysLegacy(K pattern) {
+
+        Map<String, CompletableFuture<List<K>>> executions = executeOnUpstream(commands -> commands.keysLegacy(pattern));
 
         return new PipelinedRedisFuture<>(executions, objectPipelinedRedisFuture -> {
             List<K> result = new ArrayList<>();
@@ -290,12 +312,29 @@ public RedisFuture<List<K>> keys(K pattern) {
     }
 
     @Override
-    public RedisFuture<Long> keys(KeyStreamingChannel<K> channel, K pattern) {
+    public RedisFuture<Long> keys(KeyStreamingChannel<String> channel, String pattern) {
 
         Map<String, CompletableFuture<Long>> executions = executeOnUpstream(commands -> commands.keys(channel, pattern));
         return MultiNodeExecution.aggregateAsync(executions);
     }
 
+    /**
+     * Find all keys matching the given pattern (legacy overload).
+     *
+     * @param channel the channel.
+     * @param pattern the pattern.
+     * @return Long array-reply list of keys matching {@code pattern}.
+     * @deprecated Use {@link #keys(KeyStreamingChannel, String)} instead. This legacy overload will be removed in a later
+     *             version.
+     */
+    @Deprecated
+    @Override
+    public RedisFuture<Long> keysLegacy(KeyStreamingChannel<K> channel, K pattern) {
+
+        Map<String, CompletableFuture<Long>> executions = executeOnUpstream(commands -> commands.keysLegacy(channel, pattern));
+        return MultiNodeExecution.aggregateAsync(executions);
+    }
+
     @Override
     public RedisFuture<List<JsonValue>> jsonMGet(JsonPath jsonPath, K... keys) {
         Map<Integer, List<K>> partitioned = SlotHash.partition(codec, Arrays.asList(keys));