看到很多人问t-io怎么集群，正好自己也要实现集群，那就开干吧。记忆中隐约记得老谭说过内置了集群，就去翻了下代码，果然有！

第一步：集群需要配置一个redis，这里使用redisson，redis可以设置成集群或者单机模式

public class RedissonConfig {
    private static final Logger logger = LoggerFactory.getLogger(RedissonConfig.class);
    private static RedissonConfig redissonConfig;
    private static RedissonClient redissonClient;

    public static RedissonConfig newInstance() {
        if (redissonConfig == null) {
            synchronized (RedissonConfig.class) {
                   if (redissonConfig == null) {
                    init();
                }
            }
        }
        return redissonConfig;
    }

private static void init() {
    if (redissonConfig == null) {
        String redisCluster = P.get("redisCluster");
       if("0".equals(redisCluster)){
           String host = P.get("redis.host");
           if(StrUtil.isEmpty(host)) {
               logger.error("redis服务器IP不能为空");
           }
           Integer port = P.getInt("redis.port");
           if(port == null) {
               logger.error("redis端口不能为空");
           }
           Config config = new Config();
           SingleServerConfig singleServerConfig = config.useSingleServer();
           singleServerConfig.setIdleConnectionTimeout(5000);
           singleServerConfig.setConnectTimeout(5000);
           singleServerConfig.setConnectionMinimumIdleSize(300);
           singleServerConfig.setConnectionPoolSize(1000);
           singleServerConfig.setTimeout(2000);
           String password = P.get("redis.password");
           if (!StrUtil.isEmpty(password)) {
               singleServerConfig.setAddress("redis://"+host+":"+port)
                       .setPassword(AES256Utils.decrypt(password))
                       .setTimeout(P.getInt("redis.timeout"));
           } else {
               singleServerConfig.setAddress("redis://"+host+":"+port)
                       .setTimeout(P.getInt("redis.timeout"));
           }
           try {
               redissonClient = Redisson.create(config);
               redissonConfig = new RedissonConfig();
           } catch (Exception e) {
               logger.error("redis连接失败", e);
           }
       }else{
           String[] hosts = P.get("redis.urls").split(",");
           if (hosts==null||hosts.length<1) {
               logger.error("redis服务器IP不能为空");
           }
           Config config = new Config();
           ClusterServersConfig clusterServersConfig = config.useClusterServers();
           clusterServersConfig.setIdleConnectionTimeout(5000);
           clusterServersConfig.setConnectTimeout(5000);
           clusterServersConfig.setReadMode(ReadMode.SLAVE);
           clusterServersConfig.setMasterConnectionPoolSize(1000);
           clusterServersConfig.setSlaveConnectionPoolSize(1000);
           clusterServersConfig.setSubscriptionConnectionPoolSize(1000);
           clusterServersConfig.setSubscriptionMode(SubscriptionMode.SLAVE);
           for(String host:hosts){
               clusterServersConfig.addNodeAddress("redis://"+host);
           }
           String password = P.get("redis.password");
           if (!StrUtil.isEmpty(password)) {
                 clusterServersConfig.setPassword(AES256Utils.decrypt(password)).setTimeout(P.getInt("redis.timeout"));
           } else {
               clusterServersConfig.setTimeout(P.getInt("redis.timeout"));
           }
           try {
               redissonClient = Redisson.create(config);
               redissonConfig = new RedissonConfig();
           } catch (Exception e) {
               logger.error("redis连接失败", e);
           }
       }
    }
}

public RedissonClient getRedissonClient() {
    return redissonClient;
}

}

第二步：开启内置集群能力，t-io已经内置了消息集群分发，在ShowcaseWebsocketStarter类的ShowcaseWebsocketStarter方法中加入以下代码即可

RedissonTioClusterTopic redissonTioClusterTopic = new RedissonTioClusterTopic(ShowcaseServerConfig.CHANNEL, RedissonConfig.newInstance().getRedissonClient());
TioClusterConfig tioClusterConfig = new TioClusterConfig(redissonTioClusterTopic);
tioClusterConfig.setCluster4group(true);
serverTioConfig.setTioClusterConfig(tioClusterConfig);

pom.xml集成org.redisson，这里的版本是3.10.4

app.properties增加redis配置

redis.port=6379
redis.host=localhost
redis.password=
redis.timeout=3000

这样就激活了内置的消息集群分发，如果需要获取群组内的组员则需要自己实现此业务，这里附上我自己的实现，在ShowcaseWsMsgHandler.onAfterHandshaked中：

    //获取当前人员信息
    JSONObject user = getUser(channelContext.userid);
    if (user == null) {
        Tio.remove(channelContext,"User does not exist");
        return;
    }
    String groupId = user.getString("groupId");

    //绑定到群组，后面会有群发
    Tio.bindGroup(channelContext, groupId);

    //将当前用户映射到对应的组内
    RSetMultimap<String, JSONObject> groupUserList = redissonClient.getSetMultimap(Const.GROUP_ID);
    groupUserList.put(groupId, user);

        //组装消息体，发送登录消息给群组内所有人
        JSONObject messageObject = new JSONObject();
        messageObject.put("fromId",user.getString("userId"));
        messageObject.put("fromName",user.getString("realName"));
        messageObject.put("userInfo",user);
        messageObject.put("type",MessageType.SYSADMINMESSAGE.getCode());
        messageObject.put("message", String.format(Const.userInTemplate, String.format(Const.FROMUSERNAME,user.getString("realName")),
                Tio.groupCount(channelContext.tioConfig, groupId)));
        messageObject.put("time", System.currentTimeMillis());
        WsResponse wsResponse = WsResponse.fromText(messageObject.toJSONString(), ShowcaseServerConfig.CHARSET);
        Tio.sendToGroup(channelContext.tioConfig, groupId, wsResponse);

        //获取组内成员
        Set<JSONObject> userInfos = groupUserList.get(groupId);

        //发送消息给自己刷新列表
        messageObject.remove("userInfo");
        messageObject.put("type",MessageType.FLISHUSERLISTNOTIC.getCode());
        messageObject.put("userInfos",userInfos);
        messageObject.put("time", System.currentTimeMillis());
        WsResponse wsResponse2 = WsResponse.fromText(messageObject.toJSONString(), ShowcaseServerConfig.CHARSET);
        Tio.send(channelContext, wsResponse2);
        log.info("{} a list of members sent to you： {}, userSize: {}", user.getString("userId"), userInfos.toString(), Tio.groupCount(channelContext.tioConfig, groupId));

至此，一个简单的消息集群就完成了！