private String getHostName(String instanceName) {
        final int pos = instanceName.indexOf(':');
        if (pos > 0) {
            return instanceName.substring(0, pos);
        } else {
            return instanceName;
        }
    }
@author emeroad
@author minwoo.jung
@author HyunGil Jeong
web/src/main/java/com/navercorp/pinpoint/web/applicationmap/nodes/ServerBuilder.java