Revert "GC unused DiskState"

12 files changed, 431 insertions, 7 deletions

diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerStateRestAPI.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerStateRestAPI.java
index 6c80973c4af..169684aa742 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerStateRestAPI.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerStateRestAPI.java
@@ -2,12 +2,7 @@
 package com.yahoo.vespa.clustercontroller.core.restapiv2;
 
 import com.yahoo.vespa.clustercontroller.core.RemoteClusterControllerTaskScheduler;
-import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.ClusterListRequest;
-import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.ClusterStateRequest;
-import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.NodeStateRequest;
-import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.ServiceStateRequest;
-import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.SetNodeStateRequest;
-import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.SetNodeStatesForClusterRequest;
+import com.yahoo.vespa.clustercontroller.core.restapiv2.requests.*;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.StateRestAPI;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.InternalFailure;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.OtherMasterException;
@@ -17,6 +12,7 @@ import com.yahoo.vespa.clustercontroller.utils.staterestapi.requests.UnitStateRe
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.SetResponse;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.UnitResponse;
 
+import java.util.EnumSet;
 import java.util.Map;
 import java.util.Objects;
 import java.util.logging.Logger;
@@ -90,6 +86,10 @@ public class ClusterControllerStateRestAPI implements StateRestAPI {
             public Request<? extends UnitResponse> visitNode(Id.Node id)  {
                 return new NodeStateRequest(id);
             }
+            @Override
+            public Request<? extends UnitResponse> visitPartition(Id.Partition id)  {
+                return new PartitionStateRequest(id, EnumSet.of(VerboseReport.STATISTICS));
+            }
         });
         if (req instanceof ClusterListRequest) {
             log.fine("Got cluster list request");
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Id.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Id.java
index 1a0fe6cdf8e..ed5af93d7fb 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Id.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Id.java
@@ -52,4 +52,16 @@ public class Id {
         public String toString() { return super.toString() + "/" + id; }
     }
 
+    public static class Partition extends Node {
+        private final int id;
+
+        public Partition(Node n, int partition) {
+            super(n, n.id);
+            this.id = partition;
+        }
+
+        public final int getPartitionIndex() { return id; }
+        public String toString() { return super.toString() + "/" + id; }
+    }
+
 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Response.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Response.java
index 82512262b4a..17949b82365 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Response.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/Response.java
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core.restapiv2;
 
+import com.yahoo.vdslib.state.DiskState;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.InternalFailure;
@@ -31,6 +32,10 @@ public class Response {
             this.id = parseId(ns.getState());
             this.reason = ns.getDescription();
         }
+        public UnitStateImpl(DiskState ds) throws StateRestApiException {
+            this.id = parseId(ds.getState());
+            this.reason = ds.getDescription();
+        }
 
         public String parseId(State id) throws StateRestApiException {
             switch (id) {
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java
index 04fd154ff6b..4dc73f4d0dd 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java
@@ -6,6 +6,7 @@ import com.yahoo.vespa.clustercontroller.core.RemoteClusterControllerTaskSchedul
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.MissingUnitException;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.OperationNotSupportedForUnitException;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.StateRestApiException;
+import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.UnitResponse;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -18,6 +19,7 @@ public class UnitPathResolver<T> {
         Request<? extends T> visitCluster(Id.Cluster id) throws StateRestApiException;
         Request<? extends T> visitService(Id.Service id) throws StateRestApiException;
         Request<? extends T> visitNode(Id.Node id) throws StateRestApiException;
+        Request<? extends T> visitPartition(Id.Partition id) throws StateRestApiException;
 
     }
 
@@ -38,6 +40,7 @@ public class UnitPathResolver<T> {
         public Request<? extends T> visitCluster(Id.Cluster id) throws StateRestApiException { return fail(); }
         public Request<? extends T> visitService(Id.Service id) throws StateRestApiException { return fail(); }
         public Request<? extends T> visitNode(Id.Node id) throws StateRestApiException { return fail(); }
+        public Request<? extends T> visitPartition(Id.Partition id) throws StateRestApiException { return fail(); }
 
     }
 
@@ -84,7 +87,16 @@ public class UnitPathResolver<T> {
         if (path.length == 3) {
             return visitor.visitNode(node);
         }
-        throw new MissingUnitException(path, 3);
+        Id.Partition partition;
+        try{
+            partition = new Id.Partition(node, Integer.valueOf(path[3]));
+        } catch (NumberFormatException e) {
+            throw new MissingUnitException(path, 3);
+        }
+        if (path.length == 4) {
+            return visitor.visitPartition(partition);
+        }
+        throw new MissingUnitException(path, 4);
     }
 
 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/PartitionStateRequest.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/PartitionStateRequest.java
new file mode 100644
index 00000000000..bb42af45ef3
--- /dev/null
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/PartitionStateRequest.java
@@ -0,0 +1,69 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core.restapiv2.requests;
+
+import com.yahoo.vdslib.state.DiskState;
+import com.yahoo.vdslib.state.NodeState;
+import com.yahoo.vespa.clustercontroller.core.RemoteClusterControllerTask;
+import com.yahoo.vespa.clustercontroller.core.hostinfo.Metrics;
+import com.yahoo.vespa.clustercontroller.core.restapiv2.Id;
+import com.yahoo.vespa.clustercontroller.core.restapiv2.Request;
+import com.yahoo.vespa.clustercontroller.core.restapiv2.Response;
+import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.StateRestApiException;
+
+import java.util.Set;
+import java.util.logging.Logger;
+
+public class PartitionStateRequest extends Request<Response.PartitionResponse> {
+    private static final Logger log = Logger.getLogger(PartitionStateRequest.class.getName());
+    private final Id.Partition id;
+    private final Set<VerboseReport> verboseReports;
+
+    public PartitionStateRequest(Id.Partition id, Set<VerboseReport> verboseReports) {
+        super(MasterState.MUST_BE_MASTER);
+        this.id = id;
+        this.verboseReports = verboseReports;
+    }
+
+    @Override
+    public Response.PartitionResponse calculateResult(RemoteClusterControllerTask.Context context)
+            throws StateRestApiException {
+        Response.PartitionResponse result = new Response.PartitionResponse();
+        if (verboseReports.contains(VerboseReport.STATISTICS)) {
+            fillInMetrics(context.cluster.getNodeInfo(id.getNode()).getHostInfo().getMetrics(), result);
+        }
+        NodeState nodeState = context.currentConsolidatedState.getNodeState(id.getNode());
+        DiskState diskState = new DiskState();
+        result.addState("generated", new Response.UnitStateImpl(diskState));
+
+        return result;
+    }
+
+    private static void fillInMetrics(Metrics metrics, Response.PartitionResponse result) {
+        for (Metrics.Metric metric: metrics.getMetrics()) {
+            fillInMetricValue(metric.getName(), metric.getValue(), result);
+        }
+    }
+
+    private static void fillInMetricValue(
+            String name, Metrics.Value value, Response.PartitionResponse result) {
+        if (name.equals("vds.datastored.alldisks.docs")) {
+            if (value.getLast() == null) {
+                log.warning("Proper doc count value did not exist in value set.");
+                return;
+            }
+            result.addMetric("unique-document-count", value.getLast());
+        } else if (name.equals("vds.datastored.alldisks.bytes")) {
+            if (value.getLast() == null) {
+                log.warning("Proper doc size value did not exist in value set.");
+                return;
+            }
+            result.addMetric("unique-document-total-size", value.getLast());
+        } else if (name.equals("vds.datastored.alldisks.buckets")) {
+            if (value.getLast() == null) {
+                log.warning("Proper bucket count value did not exist in value set.");
+                return;
+            }
+            result.addMetric("bucket-count", value.getLast());
+        }
+    }
+}
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGeneratorTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGeneratorTest.java
index 0798e6174f9..bf191768892 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGeneratorTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGeneratorTest.java
@@ -2,6 +2,7 @@
 package com.yahoo.vespa.clustercontroller.core;
 
 import com.yahoo.vdslib.distribution.ConfiguredNode;
+import com.yahoo.vdslib.state.DiskState;
 import com.yahoo.vdslib.state.Node;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
index d33d235bc66..bd77f42ff8a 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
@@ -2,6 +2,7 @@
 package com.yahoo.vespa.clustercontroller.core;
 
 import com.yahoo.vdslib.distribution.ConfiguredNode;
+import com.yahoo.vdslib.state.DiskState;
 import com.yahoo.vdslib.state.Node;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/NotMasterTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/NotMasterTest.java
index b0355844341..4ec5893c1e7 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/NotMasterTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/NotMasterTest.java
@@ -54,6 +54,12 @@ public class NotMasterTest extends StateRestApiTest {
             assertTrue(e.getMessage(), e.getMessage().contains("No known master cluster controller"));
         }
         try{
+            restAPI.getState(new StateRequest("music/storage/1/0", 0));
+            fail();
+        } catch (UnknownMasterException e) {
+            assertTrue(e.getMessage(), e.getMessage().contains("No known master cluster controller"));
+        }
+        try{
             restAPI.setUnitState(new SetNodeStateTest.SetUnitStateRequestImpl("music/storage/1")
                                     .setNewState("user", "down", "test"));
             fail();
@@ -112,6 +118,14 @@ public class NotMasterTest extends StateRestApiTest {
             assertEquals(e.getPort(), getDefaults().vespaWebServicePort());
         }
         try{
+            restAPI.getState(new StateRequest("music/storage/1/0", 0));
+            fail();
+        } catch (OtherMasterException e) {
+            assertTrue(e.getMessage(), e.getMessage().contains("Cluster controller not master. Use master at otherhost:" + getDefaults().vespaWebServicePort() + "."));
+            assertEquals("otherhost", e.getHost());
+            assertEquals(e.getPort(), getDefaults().vespaWebServicePort());
+        }
+        try{
             restAPI.setUnitState(new SetNodeStateTest.SetUnitStateRequestImpl("music/storage/1")
                     .setNewState("user", "down", "test"));
             fail();
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/PartitionTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/PartitionTest.java
new file mode 100644
index 00000000000..106803ec3f1
--- /dev/null
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/PartitionTest.java
@@ -0,0 +1,49 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core.restapiv2;
+
+import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.UnitResponse;
+import org.codehaus.jettison.json.JSONObject;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class PartitionTest extends StateRestApiTest {
+
+    @Test
+    public void testPartition() throws Exception {
+        setUp(true);
+        UnitResponse response = restAPI.getState(new StateRequest("music/storage/1/0", 0));
+        String expected =
+                "{\n" +
+                "  \"state\": {\"generated\": {\n" +
+                "    \"state\": \"up\",\n" +
+                "    \"reason\": \"\"\n" +
+                "  }},\n" +
+                "  \"metrics\": {\n" +
+                "    \"bucket-count\": 1,\n" +
+                "    \"unique-document-count\": 2,\n" +
+                "    \"unique-document-total-size\": 3\n" +
+                "  }\n" +
+                "}";
+        assertEquals(expected, jsonWriter.createJson(response).toString(2));
+    }
+
+    @Test
+    public void testRecursiveCluster() throws Exception {
+        setUp(true);
+        UnitResponse response = restAPI.getState(new StateRequest("music/storage/1/0", 1));
+        String expected =
+                "{\n" +
+                "  \"state\": {\"generated\": {\n" +
+                "    \"state\": \"up\",\n" +
+                "    \"reason\": \"\"\n" +
+                "  }},\n" +
+                "  \"metrics\": {\n" +
+                "    \"bucket-count\": 1,\n" +
+                "    \"unique-document-count\": 2,\n" +
+                "    \"unique-document-total-size\": 3\n" +
+                "  }\n" +
+                "}";
+        assertEquals(expected, jsonWriter.createJson(response).toString(2));
+    }
+}
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/SetNodeStateTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/SetNodeStateTest.java
index 0e9a4808e9b..03fdb15971f 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/SetNodeStateTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/SetNodeStateTest.java
@@ -366,6 +366,16 @@ public class SetNodeStateTest extends StateRestApiTest {
         } catch (OperationNotSupportedForUnitException e) {
             assertTrue(e.getMessage(), e.getMessage().contains(wrongUnitMessage));
         }
+
+        // ... setting at node-level is allowed
+
+        try{
+            restAPI.setUnitState(new SetUnitStateRequestImpl(
+                    "music/storage/1/0").setNewState("user", "down", "testing"));
+            fail();
+        } catch (OperationNotSupportedForUnitException e) {
+            assertTrue(e.getMessage(), e.getMessage().contains(wrongUnitMessage));
+        }
     }
 
     @Test
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/state/DiskState.java b/vdslib/src/main/java/com/yahoo/vdslib/state/DiskState.java
new file mode 100644
index 00000000000..1a05f8ab565
--- /dev/null
+++ b/vdslib/src/main/java/com/yahoo/vdslib/state/DiskState.java
@@ -0,0 +1,135 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vdslib.state;
+
+import com.yahoo.text.StringUtilities;
+
+import java.util.StringTokenizer;
+import java.text.ParseException;
+
+/**
+ *
+ */
+public class DiskState implements Cloneable {
+    private State state = State.UP;
+    private String description = "";
+    private double capacity = 1.0;
+
+    public DiskState() {}
+    public DiskState(State s) {
+        setState(s);
+    }
+    public DiskState(State s, String description, double capacity) {
+        setState(s); // Set via set methods, so we can have illegal argument checks only one place
+        setCapacity(capacity);
+        setDescription(description);
+    }
+    public DiskState clone() {
+        try{
+            return (DiskState) super.clone();
+        } catch (CloneNotSupportedException e) {
+            assert(false); // Should not happen
+            return null;
+        }
+    }
+
+    public DiskState(String serialized) throws ParseException {
+        StringTokenizer st = new StringTokenizer(serialized, " \t\f\r\n");
+        while (st.hasMoreTokens()) {
+            String token = st.nextToken();
+            int index = token.indexOf(':');
+            if (index < 0) {
+                throw new ParseException("Token " + token + " does not contain ':': " + serialized, 0);
+            }
+            String key = token.substring(0, index);
+            String value = token.substring(index + 1);
+            if (key.length() > 0) switch (key.charAt(0)) {
+                case 's':
+                    if (key.length() > 1) break;
+                    setState(State.get(value));
+                    continue;
+                case 'c':
+                    if (key.length() > 1) break;
+                    try{
+                        setCapacity(Double.valueOf(value));
+                    } catch (Exception e) {
+                        throw new ParseException("Illegal disk capacity '" + value + "'. Capacity must be a positive floating point number", 0);
+                    }
+                    continue;
+                case 'm':
+                    if (key.length() > 1) break;
+                    description = StringUtilities.unescape(value);
+                    continue;
+                default:
+                    break;
+            }
+            // Ignore unknown tokens
+        }
+    }
+
+    public String serialize(String prefix, boolean includeDescription) {
+        boolean empty = true;
+        StringBuilder sb = new StringBuilder();
+        if (!state.equals(State.UP) || prefix.length() < 2) {
+            sb.append(prefix).append("s:").append(state.serialize());
+            empty = false;
+        }
+        if (Math.abs(capacity - 1.0) > 0.000000001) {
+            if (empty) { empty = false; } else { sb.append(' '); }
+            sb.append(prefix).append("c:").append(capacity);
+        }
+        if (includeDescription && description.length() > 0) {
+            if (!empty) { sb.append(' '); }
+            sb.append(prefix).append("m:").append(StringUtilities.escape(description, ' '));
+        }
+        return sb.toString();
+    }
+
+    public State getState() { return state; }
+    public double getCapacity() { return capacity; }
+    public String getDescription() { return description; }
+
+    public void setState(State s) {
+        if (!s.validDiskState()) {
+            throw new IllegalArgumentException("State " + s + " is not a valid disk state.");
+        }
+        state = s;
+    }
+    public void setCapacity(double capacity) {
+        if (capacity < 0) {
+            throw new IllegalArgumentException("Negative capacity makes no sense.");
+        }
+        this.capacity = capacity;
+    }
+    public void setDescription(String desc) { description = desc; }
+
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("DiskState(").append(state.serialize());
+        if (Math.abs(capacity - 1.0) > 0.00000001) {
+            sb.append(", capacity ").append(capacity);
+        }
+        if (description.length() > 0) {
+            sb.append(": ").append(description);
+        }
+        sb.append(")");
+        return sb.toString();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof DiskState)) { return false; }
+        DiskState other = (DiskState) o;
+        if (state.equals(other.state)
+            && Math.abs(capacity - other.capacity) < 0.00000001)
+        {
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        // NOTE: capacity cannot be part of the hashCode
+        return state.hashCode();
+    }
+}
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/state/DiskStateTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/state/DiskStateTestCase.java
new file mode 100644
index 00000000000..bdc3be3dc70
--- /dev/null
+++ b/vdslib/src/test/java/com/yahoo/vdslib/state/DiskStateTestCase.java
@@ -0,0 +1,116 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vdslib.state;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class DiskStateTestCase {
+
+    private static final double delta = 0.0000000001;
+
+    @Test
+    public void testEquals() {
+        DiskState d1 = new DiskState(State.UP, "", 1);
+        DiskState d2 = new DiskState(State.UP, "", 2);
+        DiskState d3 = new DiskState(State.DOWN, "Failed disk", 1);
+        DiskState d4 = new DiskState(State.DOWN, "IO error", 1);
+        DiskState d5 = new DiskState(State.UP, "", 1);
+        DiskState d6 = new DiskState(State.UP, "", 2);
+        DiskState d7 = new DiskState(State.DOWN, "Failed disk", 1);
+        DiskState d8 = new DiskState(State.DOWN, "IO error", 1);
+
+        assertEquals(d1, d5);
+        assertEquals(d2, d6);
+        assertEquals(d3, d7);
+        assertEquals(d4, d8);
+
+        assertFalse(d1.equals(d2));
+        assertFalse(d1.equals(d3));
+        assertFalse(d1.equals(d4));
+
+        assertFalse(d2.equals(d1));
+        assertFalse(d2.equals(d3));
+        assertFalse(d2.equals(d4));
+
+        assertFalse(d3.equals(d1));
+        assertFalse(d3.equals(d2));
+        assertEquals(d3, d4);
+
+        assertFalse(d4.equals(d1));
+        assertFalse(d4.equals(d2));
+        assertEquals(d4, d3);
+
+        assertFalse(d1.equals("class not instance of Node"));
+    }
+
+    @Test
+    public void testSerialization() throws ParseException {
+        DiskState d = new DiskState();
+        DiskState other = new DiskState(d.serialize("", true));
+        assertEquals(d, other);
+        assertEquals(d.toString(), other.toString());
+        assertEquals(State.UP, other.getState());
+        assertEquals(1.0, other.getCapacity(), delta);
+        assertEquals("", other.getDescription());
+        assertEquals("s:u", d.serialize("", false));
+        assertEquals("s:u", d.serialize("", true));
+        assertEquals("", d.serialize(".0.", false));
+        assertEquals("", d.serialize(".0.", true));
+
+        assertEquals(d, new DiskState(": s:u sbadkey:somevalue cbadkey:somevalue mbadkey:somevalue unknwonkey:somevalue"));
+
+        d = new DiskState(State.UP, "Slow disk", 1.0);
+        other = new DiskState(d.serialize("", true));
+        assertEquals(d, other);
+        assertEquals(d.toString(), other.toString());
+        assertEquals(State.UP, other.getState());
+        assertEquals(1.0, other.getCapacity(), delta);
+        assertEquals("Slow disk", other.getDescription());
+        assertEquals("s:u", d.serialize("", false));
+        assertEquals("s:u m:Slow\\x20disk", d.serialize("", true));
+        assertEquals("", d.serialize(".0.", false));
+        assertEquals(".0.m:Slow\\x20disk", d.serialize(".0.", true));
+
+        d = new DiskState(State.DOWN, "Failed disk", 2.0);
+        other = new DiskState(d.serialize("", true));
+        assertEquals(d, other);
+        assertEquals(d.toString(), other.toString());
+        assertEquals(State.DOWN, other.getState());
+        assertEquals(2.0, other.getCapacity(), delta);
+        assertEquals("Failed disk", other.getDescription());
+        assertEquals("s:d c:2.0", d.serialize("", false));
+        assertEquals("s:d c:2.0 m:Failed\\x20disk", d.serialize("", true));
+        assertEquals(".0.s:d .0.c:2.0", d.serialize(".0.", false));
+        assertEquals(".0.s:d .0.c:2.0 .0.m:Failed\\x20disk", d.serialize(".0.", true));
+
+        try {
+            new DiskState(State.MAINTENANCE);
+            assertTrue("Method expected to throw IllegalArgumentException", false);
+        } catch (IllegalArgumentException e) {
+            assertEquals("State " + State.MAINTENANCE + " is not a valid disk state.", e.getMessage());
+        }
+        try {
+            new DiskState(State.UP, "", -1);
+            assertTrue("Method expected to throw IllegalArgumentException", false);
+        } catch (IllegalArgumentException e) {
+            assertEquals("Negative capacity makes no sense.", e.getMessage());
+        }
+        try {
+            new DiskState("nocolon");
+            assertTrue("Method expected to throw ParseException", false);
+        } catch (ParseException e) {
+            assertEquals("Token nocolon does not contain ':': nocolon", e.getMessage());
+        }
+        try {
+            new DiskState("s:d c:badvalue");
+            assertTrue("Method expected to throw ParseException", false);
+        } catch (ParseException e) {
+            assertEquals("Illegal disk capacity 'badvalue'. Capacity must be a positive floating point number", e.getMessage());
+        }
+    }
+}