channel :{
records : {'20110' : {uid : '20110', sid : 'connector-server-1'}}, //以uid为key
groups : {'connector-server-1' : ['20110', ] } //以前端服务器Id为key
}
getMessageTargetByUids( uids, next)
getMessageTargetByServerType( serverType, next);
玩家登陆, channel.add( uid, sid);
玩家离开, channel.leave( uid, sid); //onUserLeave
有时候会清除不掉 这时候使用pushMessage会推送多条信息
