Support the MAXAGE option for CLIENT KILL (#3754)

* Support the MAXAGE option for CLIENT KILL

Starting with Redis 7.6, the CLIENT KILL command has a new option, called MAXAGE, to kill clients older than a given age. Add support for this new option.

* Ensure clients are closed in some tests

* More concise unit test code

Co-authored-by: M Sazzadul Hoque <[email protected]>

---------

Co-authored-by: Gabriel Erzse <[email protected]>
Co-authored-by: M Sazzadul Hoque <[email protected]>

src/main/java/redis/clients/jedis/Protocol.java

@@ -301,7 +301,7 @@ public static enum Keyword implements Rawable {
     DELETE, LIBRARYNAME, WITHCODE, DESCRIPTION, GETKEYS, GETKEYSANDFLAGS, DOCS, FILTERBY, DUMP,
     MODULE, ACLCAT, PATTERN, DOCTOR, LATEST, HISTORY, USAGE, SAMPLES, PURGE, STATS, LOADEX, CONFIG, ARGS, RANK,
     NOW, VERSION, ADDR, SKIPME, USER, LADDR,
-    CHANNELS, NUMPAT, NUMSUB, SHARDCHANNELS, SHARDNUMSUB, NOVALUES;
+    CHANNELS, NUMPAT, NUMSUB, SHARDCHANNELS, SHARDNUMSUB, NOVALUES, MAXAGE;
 
     private final byte[] raw;
 

src/main/java/redis/clients/jedis/commands/ClientCommands.java

@@ -30,10 +30,10 @@ public interface ClientCommands {
   String clientKill(String ip, int port);
 
   /**
-   * Close a given client connection.
+   * Close client connections based on certain selection parameters.
    *
-   * @param params Connection info will be closed
-   * @return Close success return OK
+   * @param params Parameters defining what client connections to close.
+   * @return The number of client connections that were closed.
    */
   long clientKill(ClientKillParams params);
 

src/main/java/redis/clients/jedis/params/ClientKillParams.java

@@ -67,6 +67,16 @@ public ClientKillParams laddr(String ip, int port) {
     return addParam(Keyword.LADDR, ip + ':' + port);
   }
 
+  /**
+   * Kill clients older than {@code maxAge} seconds.
+   *
+   * @param maxAge Clients older than this number of seconds will be killed.
+   * @return The {@code ClientKillParams} instance, for call chaining.
+   */
+  public ClientKillParams maxAge(long maxAge) {
+    return addParam(Keyword.MAXAGE, maxAge);
+  }
+
   @Override
   public void addParams(CommandArguments args) {
     params.forEach(kv -> args.add(kv.getKey()).add(kv.getValue()));

src/test/java/redis/clients/jedis/commands/jedis/ClientCommandsTest.java

@@ -222,17 +222,38 @@ public void killAddrIpPort() {
 
   @Test
   public void killUser() {
-    Jedis client2 = new Jedis(hnp.getHost(), hnp.getPort(), 500);
     client.aclSetUser("test_kill", "on", "+acl", ">password1");
-    try {
+    try (Jedis client2 = new Jedis(hnp.getHost(), hnp.getPort(), 500)) {
       client2.auth("test_kill", "password1");
+
       assertEquals(1, jedis.clientKill(new ClientKillParams().user("test_kill")));
       assertDisconnected(client2);
     } finally {
       jedis.aclDelUser("test_kill");
     }
   }
 
+  @Test
+  public void killMaxAge() throws InterruptedException {
+    long maxAge = 2;
+
+    // sleep twice the maxAge, to be sure
+    Thread.sleep(maxAge * 2 * 1000);
+
+    try (Jedis client2 = new Jedis(hnp.getHost(), hnp.getPort(), 500)) {
+      client2.auth("foobared");
+
+      long killedClients = jedis.clientKill(new ClientKillParams().maxAge(maxAge));
+
+      // The reality is that some tests leak clients, so we can't assert
+      // on the exact number of killed clients.
+      assertTrue(killedClients > 0);
+
+      assertDisconnected(client);
+      assertConnected(client2);
+    }
+  }
+
   @Test
   public void clientInfo() {
     String info = client.clientInfo();
@@ -267,6 +288,10 @@ private void assertDisconnected(Jedis j) {
     }
   }
 
+  private void assertConnected(Jedis j) {
+    assertEquals("PONG", j.ping());
+  }
+
   private String findInClientList() {
     for (String clientInfo : jedis.clientList().split("\n")) {
       if (pattern.matcher(clientInfo).find()) {