public boolean matchesWithHostName(String hostName) {
            Matcher matcher = instancePattern.matcher(hostName);
            return matcher.matches();
        }
The group of instances according to hostPatterns defined in Zabbix rule file
oap-server/server-receiver-plugin/skywalking-zabbix-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zabbix/provider/ZabbixMetrics.java