Queries are routed to unhealthy backends about presto-gateway HOT 9 OPEN

public static String getTrinoClusterToken(String targetUrl, MonitorConfiguration monitorConfiguration){
        HttpURLConnection loginConnection = null;
        try{
            URL loginUrl = new URL(String.format("%s/ui/login", targetUrl));
            loginConnection = (HttpURLConnection) loginUrl.openConnection();
            loginConnection.setRequestMethod("POST");
            loginConnection.setDoOutput(true);
            loginConnection.setInstanceFollowRedirects(false);
            loginConnection.addRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            loginConnection.setRequestProperty("charset", "utf-8");
            String password = "";
            if(!Strings.isNullOrEmpty(monitorConfiguration.getMonitorPassword())){
                password = monitorConfiguration.getMonitorPassword();
            }
            String loginData = String.format("username=%s&password=%s", monitorConfiguration.getMonitorUser(), password);
            byte[] postData = loginData.getBytes( StandardCharsets.UTF_8);
            loginConnection.connect();
            DataOutputStream out = new DataOutputStream(loginConnection.getOutputStream());
            out.write(postData);
            String token = loginConnection.getHeaderField("Set-Cookie");
            out.close();
            // data simple: Trino-UI-Token=xx;Version=1;Path=/ui;HttpOnly
            // so we need split by ;
            return token.split(";")[0];

        }catch (Exception e){
            log.error("Error login trino cluster from {},reason is:  {}", targetUrl, e);
        }finally {
            if (loginConnection != null) {
                loginConnection.disconnect();
            }
        }
        return "";
    }

public static String requestTrinoClusterStatsWithToken(String targetUrl, String token){
        HttpURLConnection apiConnection = null;
        try{
            URL apiURL = new URL(String.format("%s/ui/api/stats", targetUrl));
            apiConnection = (HttpURLConnection) apiURL.openConnection();
            apiConnection.setRequestMethod("GET");
            apiConnection.setRequestProperty("Cookie", token);
            int responseCode = apiConnection.getResponseCode();
            if (responseCode == HttpStatus.SC_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader((InputStream) apiConnection.getContent()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    sb.append(line).append("\n");
                }
                return sb.toString();
            }
        }catch (Exception e){
            log.error("Error fetching cluster stats from [{}]", targetUrl, e);
        }finally {
            if (apiConnection != null){
                apiConnection.disconnect();
            }
        }
        return null;
    }