diff --git a/src/main/java/org/apache/cassandra/gms/ApplicationState.java b/src/main/java/org/apache/cassandra/gms/ApplicationState.java
new file mode 100644
index 0000000..31958cf
--- /dev/null
+++ b/src/main/java/org/apache/cassandra/gms/ApplicationState.java
@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * Copyright (C) 2015 ScyllaDB
+ */
+/*
+ * Moddified by ScyllaDB
+ */
+
+package org.apache.cassandra.gms;
+
+public enum ApplicationState
+{
+    STATUS,
+    LOAD,
+    SCHEMA,
+    DC,
+    RACK,
+    RELEASE_VERSION,
+    REMOVAL_COORDINATOR,
+    INTERNAL_IP,
+    RPC_ADDRESS,
+    X_11_PADDING, // padding specifically for 1.1
+    SEVERITY,
+    NET_VERSION,
+    HOST_ID,
+    TOKENS,
+    // pad to allow adding new states to existing cluster
+    X1,
+    X2,
+    X3,
+    X4,
+    X5,
+    X6,
+    X7,
+    X8,
+    X9,
+    X10,
+}
diff --git a/src/main/java/org/apache/cassandra/gms/EndpointState.java b/src/main/java/org/apache/cassandra/gms/EndpointState.java
new file mode 100644
index 0000000..c786d94
--- /dev/null
+++ b/src/main/java/org/apache/cassandra/gms/EndpointState.java
@@ -0,0 +1,103 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * Copyright (C) 2015 ScyllaDB
+ */
+/*
+ * Moddified by ScyllaDB
+ */
+package org.apache.cassandra.gms;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * This abstraction represents both the HeartBeatState and the ApplicationState
+ * in an EndpointState instance. Any state for a given endpoint can be retrieved
+ * from this instance.
+ */
+
+public class EndpointState {
+    private volatile HeartBeatState hbState;
+
+    final Map<ApplicationState, String> applicationState = new HashMap<ApplicationState, String>();
+
+    private volatile long updateTimestamp;
+    private volatile boolean isAlive;
+    ApplicationState[] applicationValues;
+
+    EndpointState(HeartBeatState initialHbState) {
+        applicationValues = ApplicationState.values();
+        hbState = initialHbState;
+        updateTimestamp = System.nanoTime();
+        isAlive = true;
+    }
+
+    HeartBeatState getHeartBeatState() {
+        return hbState;
+    }
+
+    void setHeartBeatState(HeartBeatState newHbState) {
+        hbState = newHbState;
+    }
+
+    public String getApplicationState(ApplicationState key) {
+        return applicationState.get(key);
+    }
+
+    /**
+     * TODO replace this with operations that don't expose private state
+     */
+    @Deprecated
+    public Map<ApplicationState, String> getApplicationStateMap() {
+        return applicationState;
+    }
+
+    void addApplicationState(ApplicationState key, String value) {
+        applicationState.put(key, value);
+    }
+
+    void addApplicationState(int key, String value) {
+        addApplicationState(applicationValues[key], value);
+    }
+
+    /* getters and setters */
+    /**
+     * @return System.nanoTime() when state was updated last time.
+     */
+    public long getUpdateTimestamp() {
+        return updateTimestamp;
+    }
+
+    public void setUpdateTimestamp(long ts) {
+        updateTimestamp = ts;
+    }
+
+    public boolean isAlive() {
+        return isAlive;
+    }
+
+    public void setAliave(boolean alive) {
+        isAlive = alive;
+    }
+
+    public String toString() {
+        return "EndpointState: HeartBeatState = " + hbState + ", AppStateMap = "
+                + applicationState;
+    }
+}
diff --git a/src/main/java/org/apache/cassandra/gms/HeartBeatState.java b/src/main/java/org/apache/cassandra/gms/HeartBeatState.java
new file mode 100644
index 0000000..0af0ef6
--- /dev/null
+++ b/src/main/java/org/apache/cassandra/gms/HeartBeatState.java
@@ -0,0 +1,65 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * Copyright (C) 2015 ScyllaDB
+ */
+/*
+ * Moddified by ScyllaDB
+ */
+package org.apache.cassandra.gms;
+
+/**
+ * HeartBeat State associated with any given endpoint.
+ */
+class HeartBeatState {
+    private int generation;
+    private int version;
+
+    HeartBeatState(int gen) {
+        this(gen, 0);
+    }
+
+    HeartBeatState(int gen, int ver) {
+        generation = gen;
+        version = ver;
+    }
+
+    int getGeneration() {
+        return generation;
+    }
+
+    void updateHeartBeat() {
+    }
+
+    int getHeartBeatVersion() {
+        return version;
+    }
+
+    void forceNewerGenerationUnsafe() {
+        generation += 1;
+    }
+
+    void forceHighestPossibleVersionUnsafe() {
+        version = Integer.MAX_VALUE;
+    }
+
+    public String toString() {
+        return String.format("HeartBeat: generation = %d, version = %d",
+                generation, version);
+    }
+}