diff --git a/src/main/java/com/nhn/hippo/web/calltree/server/AgentIdNodeSelector.java b/src/main/java/com/nhn/hippo/web/calltree/server/AgentIdNodeSelector.java
new file mode 100644
index 000000000..d89606224
--- /dev/null
+++ b/src/main/java/com/nhn/hippo/web/calltree/server/AgentIdNodeSelector.java
@@ -0,0 +1,21 @@
+package com.nhn.hippo.web.calltree.server;
+
+import com.profiler.common.bo.SpanBo;
+import com.profiler.common.bo.SubSpanBo;
+
+/**
+ *
+ */
+public class AgentIdNodeSelector implements NodeSelector {
+
+    @Override
+    public String getServerId(SpanBo span) {
+        return span.getEndPoint();
+    }
+
+    @Override
+    public String getServerId(SubSpanBo span) {
+        return span.getEndPoint();
+    }
+
+}
diff --git a/src/main/java/com/nhn/hippo/web/calltree/server/ApplicationIdNodeSelector.java b/src/main/java/com/nhn/hippo/web/calltree/server/ApplicationIdNodeSelector.java
new file mode 100644
index 000000000..018f8a6bb
--- /dev/null
+++ b/src/main/java/com/nhn/hippo/web/calltree/server/ApplicationIdNodeSelector.java
@@ -0,0 +1,19 @@
+package com.nhn.hippo.web.calltree.server;
+
+import com.profiler.common.bo.SpanBo;
+import com.profiler.common.bo.SubSpanBo;
+
+/**
+ *
+ */
+public class ApplicationIdNodeSelector implements NodeSelector {
+    @Override
+    public String getServerId(SpanBo span) {
+        return span.getServiceName();
+    }
+
+    @Override
+    public String getServerId(SubSpanBo span) {
+        return span.getDestinationId();
+    }
+}
diff --git a/src/main/java/com/nhn/hippo/web/calltree/server/NodeIdGenerator.java b/src/main/java/com/nhn/hippo/web/calltree/server/NodeIdGenerator.java
deleted file mode 100644
index 7d17dada6..000000000
--- a/src/main/java/com/nhn/hippo/web/calltree/server/NodeIdGenerator.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package com.nhn.hippo.web.calltree.server;
-
-import com.profiler.common.bo.SpanBo;
-import com.profiler.common.bo.SubSpanBo;
-
-/**
- * 
- * @author netspider
- * 
- */
-public enum NodeIdGenerator {
-
-	BY_SERVER_INSTANCE, BY_APPLICATION_NAME;
-
-	public String makeServerId(SpanBo span) {
-		if (this == BY_SERVER_INSTANCE) {
-			return span.getEndPoint();
-		} else if (this == BY_APPLICATION_NAME) {
-			return span.getServiceName();
-		} else {
-			throw new IllegalArgumentException();
-		}
-	}
-
-	public String makeServerId(SubSpanBo span) {
-		if (this == BY_SERVER_INSTANCE) {
-			return span.getEndPoint();
-		} else if (this == BY_APPLICATION_NAME) {
-			return span.getDestinationId();
-		} else {
-			throw new IllegalArgumentException();
-		}
-	}
-}
diff --git a/src/main/java/com/nhn/hippo/web/calltree/server/NodeSelector.java b/src/main/java/com/nhn/hippo/web/calltree/server/NodeSelector.java
new file mode 100644
index 000000000..6d3dd5ece
--- /dev/null
+++ b/src/main/java/com/nhn/hippo/web/calltree/server/NodeSelector.java
@@ -0,0 +1,15 @@
+package com.nhn.hippo.web.calltree.server;
+
+import com.profiler.common.bo.SpanBo;
+import com.profiler.common.bo.SubSpanBo;
+
+/**
+ *
+ */
+public interface NodeSelector {
+
+    String getServerId(SpanBo span);
+
+    String getServerId(SubSpanBo span);
+
+}
diff --git a/src/main/java/com/nhn/hippo/web/calltree/server/Server.java b/src/main/java/com/nhn/hippo/web/calltree/server/Server.java
index 14c2ccc7e..0c3f428f6 100644
--- a/src/main/java/com/nhn/hippo/web/calltree/server/Server.java
+++ b/src/main/java/com/nhn/hippo/web/calltree/server/Server.java
@@ -20,7 +20,7 @@ public class Server implements Comparable<Server> {
 
 	protected int recursiveCallCount;
 
-	public Server(SubSpanBo span, NodeIdGenerator idGenerator) {
+	public Server(SubSpanBo span, NodeSelector nodeSelector) {
 		if (span.getServiceType().isTerminal()) {
 			this.agentIds.add(span.getAgentId());
 		} else {
@@ -33,7 +33,7 @@ public class Server implements Comparable<Server> {
 			this.applicationName = span.getEndPoint();
 			this.serviceType = ServiceType.UNKNOWN_CLOUD;
 		} else {
-			this.id = idGenerator.makeServerId(span);
+			this.id = nodeSelector.getServerId(span);
 			// this.id = span.getServiceName();
 			this.applicationName = span.getServiceName();
 			this.serviceType = span.getServiceType();
@@ -43,9 +43,9 @@ public class Server implements Comparable<Server> {
 		this.recursiveCallCount = 0;
 	}
 
-	public Server(SpanBo span, NodeIdGenerator idGenerator) {
+	public Server(SpanBo span, NodeSelector nodeSelector) {
 		// this.id = span.getServiceName();
-		this.id = idGenerator.makeServerId(span);
+		this.id = nodeSelector.getServerId(span);
 
 		if (span.getServiceType().isTerminal()) {
 			this.agentIds.add(span.getAgentId());
diff --git a/src/main/java/com/nhn/hippo/web/calltree/server/ServerCallTree.java b/src/main/java/com/nhn/hippo/web/calltree/server/ServerCallTree.java
index 1b2c14e73..bd33bffd6 100644
--- a/src/main/java/com/nhn/hippo/web/calltree/server/ServerCallTree.java
+++ b/src/main/java/com/nhn/hippo/web/calltree/server/ServerCallTree.java
@@ -29,7 +29,7 @@ public class ServerCallTree {
 
 	private final Map<String, Server> servers = new HashMap<String, Server>();
 	private final Map<String, ServerRequest> serverRequests = new HashMap<String, ServerRequest>();
-	private final NodeIdGenerator idGenerator;
+	private final NodeSelector nodeSelector;
 	private boolean isBuilt = false;
 
 	// temporary variables
@@ -39,8 +39,8 @@ public class ServerCallTree {
 	private final Map<String, String> spanIdToClientId = new HashMap<String, String>();
 	private final Map<String, TerminalStatistics> terminalRequests = new HashMap<String, TerminalStatistics>();
 
-	public ServerCallTree(NodeIdGenerator idGenerator) {
-		this.idGenerator = idGenerator;
+	public ServerCallTree(NodeSelector nodeSelector) {
+		this.nodeSelector = nodeSelector;
 	}
 
 	public void addTerminalStatistics(TerminalStatistics terminal) {
@@ -77,7 +77,7 @@ public class ServerCallTree {
     }
 
 	public void addSubSpan(SubSpanBo subSpan) {
-		Server server = new Server(subSpan, idGenerator);
+		Server server = new Server(subSpan, nodeSelector);
 
 		if (server.getId() == null) {
 			return;
@@ -100,7 +100,7 @@ public class ServerCallTree {
     }
 
 	public void addSpan(SpanBo span) {
-		Server server = new Server(span, idGenerator);
+		Server server = new Server(span, nodeSelector);
 
 		if (server.getId() == null) {
 			return;
diff --git a/src/main/java/com/nhn/hippo/web/service/FlowChartServiceImpl.java b/src/main/java/com/nhn/hippo/web/service/FlowChartServiceImpl.java
index 8f357ee84..a03f8d4d8 100755
--- a/src/main/java/com/nhn/hippo/web/service/FlowChartServiceImpl.java
+++ b/src/main/java/com/nhn/hippo/web/service/FlowChartServiceImpl.java
@@ -8,13 +8,14 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 
+import com.nhn.hippo.web.calltree.server.AgentIdNodeSelector;
+import com.nhn.hippo.web.calltree.server.ApplicationIdNodeSelector;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.util.StopWatch;
 
-import com.nhn.hippo.web.calltree.server.NodeIdGenerator;
 import com.nhn.hippo.web.calltree.server.ServerCallTree;
 import com.nhn.hippo.web.dao.ApplicationIndexDao;
 import com.nhn.hippo.web.dao.ApplicationTraceIndexDao;
@@ -101,7 +102,7 @@ public class FlowChartServiceImpl implements FlowChartService {
 	@Deprecated
 	@Override
 	public ServerCallTree selectServerCallTree(Set<TraceId> traceIds) {
-		final ServerCallTree tree = new ServerCallTree(NodeIdGenerator.BY_APPLICATION_NAME);
+		final ServerCallTree tree = new ServerCallTree(new ApplicationIdNodeSelector());
 
 		List<List<SpanBo>> traces = this.traceDao.selectSpans(traceIds);
 
@@ -166,7 +167,7 @@ public class FlowChartServiceImpl implements FlowChartService {
      * @return
      */
     private ServerCallTree createServerCallTree(List<SpanBo> transaction) {
-        ServerCallTree serverCallTree = new ServerCallTree(NodeIdGenerator.BY_SERVER_INSTANCE);
+        ServerCallTree serverCallTree = new ServerCallTree(new AgentIdNodeSelector());
         serverCallTree.addSpanList(transaction);
         return serverCallTree;
     }
@@ -192,7 +193,7 @@ public class FlowChartServiceImpl implements FlowChartService {
 	@Override
 	public ServerCallTree selectServerCallTree(Set<TraceId> traceIds, String applicationName, long from, long to) {
 		final Map<String, ServiceType> terminalQueryParams = new HashMap<String, ServiceType>();
-		final ServerCallTree tree = new ServerCallTree(NodeIdGenerator.BY_APPLICATION_NAME);
+		final ServerCallTree tree = new ServerCallTree(new ApplicationIdNodeSelector());
 
 		StopWatch watch = new StopWatch();
 		watch.start("scanNonTerminalSpans");