public ServerGroupList buildLogicalServer(final AgentHistogramList hostHistogram) {
        ServerGroupList.Builder builder = ServerGroupList.newBuilder();

        for (AgentHistogram agentHistogram : hostHistogram.getAgentHistogramList()) {
            final String instanceName = agentHistogram.getId();
            final String hostName = getHostName(agentHistogram.getId());
            final ServiceType serviceType = agentHistogram.getServiceType();

            final ServerInstance serverInstance = new ServerInstance(hostName, instanceName, serviceType);

            builder.addServerInstance(serverInstance);
        }
        return builder.build();
    }
filled with application information of physical server and service instance

@param hostHistogram
web/src/main/java/com/navercorp/pinpoint/web/applicationmap/nodes/ServerBuilder.java