Move serialization code out of AllocatedHosts

9 files changed, 238 insertions, 197 deletions

diff --git a/config-provisioning/abi-spec.json b/config-provisioning/abi-spec.json
index ac0b1cf393d..64114389751 100644
--- a/config-provisioning/abi-spec.json
+++ b/config-provisioning/abi-spec.json
@@ -8,8 +8,6 @@
     "methods": [
       "public static com.yahoo.config.provision.AllocatedHosts withHosts(java.util.Set)",
       "public java.util.Set getHosts()",
-      "public byte[] toJson()",
-      "public static com.yahoo.config.provision.AllocatedHosts fromJson(byte[], java.util.Optional)",
       "public boolean equals(java.lang.Object)",
       "public int hashCode()",
       "public java.lang.String toString()"
diff --git a/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java b/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java
index 96942c53a12..895325c502d 100644
--- a/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java
+++ b/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java
@@ -2,18 +2,7 @@
 package com.yahoo.config.provision;
 
 import com.google.common.collect.ImmutableSet;
-import com.yahoo.slime.ArrayTraverser;
-import com.yahoo.slime.Cursor;
-import com.yahoo.slime.Inspector;
-import com.yahoo.slime.Slime;
-import com.yahoo.vespa.config.SlimeUtils;
 
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Optional;
 import java.util.Set;
 
 /**
@@ -26,38 +15,9 @@ import java.util.Set;
  */
 public class AllocatedHosts {
 
-    // WARNING: Since there are multiple servers in a ZooKeeper cluster and they upgrade one by one
-    //          (and rewrite all nodes on startup), changes to the serialized format must be made
-    //          such that what is serialized on version N+1 can be read by version N:
-    //          - ADDING FIELDS: Always ok
-    //          - REMOVING FIELDS: Stop reading the field first. Stop writing it on a later version.
-    //          - CHANGING THE FORMAT OF A FIELD: Don't do it bro.
-
-    private static final String mappingKey = "mapping";
-    private static final String hostSpecKey = "hostSpec";
-    private static final String hostSpecHostNameKey = "hostName";
-    private static final String aliasesKey = "aliases";
-    private static final String hostSpecMembershipKey = "membership";
-
-    // Flavor can be removed when all allocated nodes are docker nodes
-    private static final String flavorKey = "flavor";
-
-    private static final String resourcesKey = "resources";
-    private static final String vcpuKey = "vcpu";
-    private static final String memoryKey = "memory";
-    private static final String diskKey = "disk";
-    private static final String diskSpeedKey = "diskSpeed";
-
-    /** Wanted version */
-    private static final String hostSpecVespaVersionKey = "vespaVersion";
-
-    /** Current version */
-    private static final String hostSpecCurrentVespaVersionKey = "currentVespaVersion";
-    private static final String hostSpecNetworkPortsKey = "ports";
-
     private final ImmutableSet<HostSpec> hosts;
 
-    AllocatedHosts(Set<HostSpec> hosts) {
+    private AllocatedHosts(Set<HostSpec> hosts) {
         this.hosts = ImmutableSet.copyOf(hosts);
     }
 
@@ -65,128 +25,8 @@ public class AllocatedHosts {
         return new AllocatedHosts(hosts);
     }
 
-    private void toSlime(Cursor cursor) {
-        Cursor array = cursor.setArray(mappingKey);
-        for (HostSpec host : hosts)
-            toSlime(host, array.addObject().setObject(hostSpecKey));
-    }
-
-    private void toSlime(HostSpec host, Cursor cursor) {
-        cursor.setString(hostSpecHostNameKey, host.hostname());
-        aliasesToSlime(host, cursor);
-        host.membership().ifPresent(membership -> {
-            cursor.setString(hostSpecMembershipKey, membership.stringValue());
-            cursor.setString(hostSpecVespaVersionKey, membership.cluster().vespaVersion().toFullString());
-        });
-        host.flavor().ifPresent(flavor -> toSlime(flavor, cursor));
-        host.version().ifPresent(version -> cursor.setString(hostSpecCurrentVespaVersionKey, version.toFullString()));
-        host.networkPorts().ifPresent(ports -> NetworkPortsSerializer.toSlime(ports, cursor.setArray(hostSpecNetworkPortsKey)));
-    }
-
-    private void aliasesToSlime(HostSpec spec, Cursor cursor) {
-        if (spec.aliases().isEmpty()) return;
-        Cursor aliases = cursor.setArray(aliasesKey);
-        for (String alias : spec.aliases())
-            aliases.addString(alias);
-    }
-
-    private void toSlime(Flavor flavor, Cursor object) {
-        if (flavor.isConfigured()) {
-            object.setString(flavorKey, flavor.name());
-        }
-        else {
-            NodeResources resources = flavor.resources();
-            Cursor resourcesObject = object.setObject(resourcesKey);
-            resourcesObject.setDouble(vcpuKey, resources.vcpu());
-            resourcesObject.setDouble(memoryKey, resources.memoryGb());
-            resourcesObject.setDouble(diskKey, resources.diskGb());
-            resourcesObject.setString(diskSpeedKey, diskSpeedToString(resources.diskSpeed()));
-        }
-    }
-
     /** Returns the hosts of this allocation */
     public Set<HostSpec> getHosts() { return hosts; }
-
-    private static AllocatedHosts fromSlime(Inspector inspector, Optional<NodeFlavors> nodeFlavors) {
-        Inspector array = inspector.field(mappingKey);
-        Set<HostSpec> hosts = new LinkedHashSet<>();
-        array.traverse((ArrayTraverser)(i, host) -> hosts.add(hostFromSlime(host.field(hostSpecKey), nodeFlavors)));
-        return new AllocatedHosts(hosts);
-    }
-
-    static HostSpec hostFromSlime(Inspector object, Optional<NodeFlavors> nodeFlavors) {
-        Optional<ClusterMembership> membership =
-                object.field(hostSpecMembershipKey).valid() ? Optional.of(membershipFromSlime(object)) : Optional.empty();
-        Optional<Flavor> flavor = flavorFromSlime(object, nodeFlavors);
-        Optional<com.yahoo.component.Version> version =
-                optionalString(object.field(hostSpecCurrentVespaVersionKey)).map(com.yahoo.component.Version::new);
-        Optional<NetworkPorts> networkPorts =
-                NetworkPortsSerializer.fromSlime(object.field(hostSpecNetworkPortsKey));
-        return new HostSpec(object.field(hostSpecHostNameKey).asString(), aliasesFromSlime(object), flavor, membership, version, networkPorts);
-    }
-
-    private static List<String> aliasesFromSlime(Inspector object) {
-        if ( ! object.field(aliasesKey).valid()) return Collections.emptyList();
-        List<String> aliases = new ArrayList<>();
-        object.field(aliasesKey).traverse((ArrayTraverser)(index, alias) -> aliases.add(alias.asString()));
-        return aliases;
-    }
-
-    private static Optional<Flavor> flavorFromSlime(Inspector object, Optional<NodeFlavors> nodeFlavors) {
-        if (object.field(flavorKey).valid() && nodeFlavors.isPresent() && nodeFlavors.get().exists(object.field(flavorKey).asString())) {
-            return nodeFlavors.get().getFlavor(object.field(flavorKey).asString());
-        }
-        else if (object.field(resourcesKey).valid()) {
-            Inspector resources = object.field(resourcesKey);
-            return Optional.of(new Flavor(new NodeResources(resources.field(vcpuKey).asDouble(),
-                                                            resources.field(memoryKey).asDouble(),
-                                                            resources.field(diskKey).asDouble(),
-                                                            diskSpeedFromSlime(resources.field(diskSpeedKey)))));
-        }
-        else {
-            return Optional.empty();
-        }
-    }
-
-    private static NodeResources.DiskSpeed diskSpeedFromSlime(Inspector diskSpeed) {
-        if ( ! diskSpeed.valid()) return NodeResources.DiskSpeed.fast; // TODO: Remove this line after June 2019
-        switch (diskSpeed.asString()) {
-            case "fast" : return NodeResources.DiskSpeed.fast;
-            case "slow" : return NodeResources.DiskSpeed.slow;
-            case "any" : return NodeResources.DiskSpeed.any;
-            default: throw new IllegalStateException("Illegal disk-speed value '" + diskSpeed.asString() + "'");
-        }
-    }
-
-    private static String diskSpeedToString(NodeResources.DiskSpeed diskSpeed) {
-        switch (diskSpeed) {
-            case fast : return "fast";
-            case slow : return "slow";
-            case any : return "any";
-            default: throw new IllegalStateException("Illegal disk-speed value '" + diskSpeed + "'");
-        }
-
-    }
-
-    private static ClusterMembership membershipFromSlime(Inspector object) {
-        return ClusterMembership.from(object.field(hostSpecMembershipKey).asString(),
-                                      com.yahoo.component.Version.fromString(object.field(hostSpecVespaVersionKey).asString()));
-    }
-
-    private static Optional<String> optionalString(Inspector inspector) {
-        if ( ! inspector.valid()) return Optional.empty();
-        return Optional.of(inspector.asString());
-    }
-
-    public byte[] toJson() throws IOException {
-        Slime slime = new Slime();
-        toSlime(slime.setObject());
-        return SlimeUtils.toJsonBytes(slime);
-    }
-
-    public static AllocatedHosts fromJson(byte[] json, Optional<NodeFlavors> nodeFlavors) {
-        return fromSlime(SlimeUtils.jsonToSlime(json).get(), nodeFlavors);
-    }
     
     @Override
     public boolean equals(Object other) {
diff --git a/config-provisioning/src/main/java/com/yahoo/config/provision/serialization/AllocatedHostsSerializer.java b/config-provisioning/src/main/java/com/yahoo/config/provision/serialization/AllocatedHostsSerializer.java
new file mode 100644
index 00000000000..9e01718bfc6
--- /dev/null
+++ b/config-provisioning/src/main/java/com/yahoo/config/provision/serialization/AllocatedHostsSerializer.java
@@ -0,0 +1,185 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.config.provision.serialization;
+
+import com.yahoo.config.provision.AllocatedHosts;
+import com.yahoo.config.provision.ClusterMembership;
+import com.yahoo.config.provision.Flavor;
+import com.yahoo.config.provision.HostSpec;
+import com.yahoo.config.provision.NetworkPorts;
+import com.yahoo.config.provision.NodeFlavors;
+import com.yahoo.config.provision.NodeResources;
+import com.yahoo.slime.ArrayTraverser;
+import com.yahoo.slime.Cursor;
+import com.yahoo.slime.Inspector;
+import com.yahoo.slime.Slime;
+import com.yahoo.vespa.config.SlimeUtils;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * The hosts allocated to an application.
+ * This can be serialized to/from JSON.
+ * This is immutable.
+ *
+ * @author Ulf Lilleengen
+ * @author bratseth
+ */
+public class AllocatedHostsSerializer {
+
+    // WARNING: Since there are multiple servers in a ZooKeeper cluster and they upgrade one by one
+    //          (and rewrite all nodes on startup), changes to the serialized format must be made
+    //          such that what is serialized on version N+1 can be read by version N:
+    //          - ADDING FIELDS: Always ok
+    //          - REMOVING FIELDS: Stop reading the field first. Stop writing it on a later version.
+    //          - CHANGING THE FORMAT OF A FIELD: Don't do it bro.
+
+    private static final String mappingKey = "mapping";
+    private static final String hostSpecKey = "hostSpec";
+    private static final String hostSpecHostNameKey = "hostName";
+    private static final String aliasesKey = "aliases";
+    private static final String hostSpecMembershipKey = "membership";
+
+    // Flavor can be removed when all allocated nodes are docker nodes
+    private static final String flavorKey = "flavor";
+
+    private static final String resourcesKey = "resources";
+    private static final String vcpuKey = "vcpu";
+    private static final String memoryKey = "memory";
+    private static final String diskKey = "disk";
+    private static final String diskSpeedKey = "diskSpeed";
+
+    /** Wanted version */
+    private static final String hostSpecVespaVersionKey = "vespaVersion";
+
+    /** Current version */
+    private static final String hostSpecCurrentVespaVersionKey = "currentVespaVersion";
+    private static final String hostSpecNetworkPortsKey = "ports";
+
+
+    public static byte[] toJson(AllocatedHosts allocatedHosts) throws IOException {
+        Slime slime = new Slime();
+        toSlime(allocatedHosts, slime.setObject());
+        return SlimeUtils.toJsonBytes(slime);
+    }
+
+    public static void toSlime(AllocatedHosts allocatedHosts, Cursor cursor) {
+        Cursor array = cursor.setArray(mappingKey);
+        for (HostSpec host : allocatedHosts.getHosts())
+            toSlime(host, array.addObject().setObject(hostSpecKey));
+    }
+
+    private static void toSlime(HostSpec host, Cursor cursor) {
+        cursor.setString(hostSpecHostNameKey, host.hostname());
+        aliasesToSlime(host, cursor);
+        host.membership().ifPresent(membership -> {
+            cursor.setString(hostSpecMembershipKey, membership.stringValue());
+            cursor.setString(hostSpecVespaVersionKey, membership.cluster().vespaVersion().toFullString());
+        });
+        host.flavor().ifPresent(flavor -> toSlime(flavor, cursor));
+        host.version().ifPresent(version -> cursor.setString(hostSpecCurrentVespaVersionKey, version.toFullString()));
+        host.networkPorts().ifPresent(ports -> NetworkPortsSerializer.toSlime(ports, cursor.setArray(hostSpecNetworkPortsKey)));
+    }
+
+    private static void aliasesToSlime(HostSpec spec, Cursor cursor) {
+        if (spec.aliases().isEmpty()) return;
+        Cursor aliases = cursor.setArray(aliasesKey);
+        for (String alias : spec.aliases())
+            aliases.addString(alias);
+    }
+
+    private static void toSlime(Flavor flavor, Cursor object) {
+        if (flavor.isConfigured()) {
+            object.setString(flavorKey, flavor.name());
+        }
+        else {
+            NodeResources resources = flavor.resources();
+            Cursor resourcesObject = object.setObject(resourcesKey);
+            resourcesObject.setDouble(vcpuKey, resources.vcpu());
+            resourcesObject.setDouble(memoryKey, resources.memoryGb());
+            resourcesObject.setDouble(diskKey, resources.diskGb());
+            resourcesObject.setString(diskSpeedKey, diskSpeedToString(resources.diskSpeed()));
+        }
+    }
+
+
+    public static AllocatedHosts fromJson(byte[] json, Optional<NodeFlavors> nodeFlavors) {
+        return fromSlime(SlimeUtils.jsonToSlime(json).get(), nodeFlavors);
+    }
+
+    public static AllocatedHosts fromSlime(Inspector inspector, Optional<NodeFlavors> nodeFlavors) {
+        Inspector array = inspector.field(mappingKey);
+        Set<HostSpec> hosts = new LinkedHashSet<>();
+        array.traverse((ArrayTraverser)(i, host) -> hosts.add(hostFromSlime(host.field(hostSpecKey), nodeFlavors)));
+        return AllocatedHosts.withHosts(hosts);
+    }
+
+    private static HostSpec hostFromSlime(Inspector object, Optional<NodeFlavors> nodeFlavors) {
+        Optional<ClusterMembership> membership =
+                object.field(hostSpecMembershipKey).valid() ? Optional.of(membershipFromSlime(object)) : Optional.empty();
+        Optional<Flavor> flavor = flavorFromSlime(object, nodeFlavors);
+        Optional<com.yahoo.component.Version> version =
+                optionalString(object.field(hostSpecCurrentVespaVersionKey)).map(com.yahoo.component.Version::new);
+        Optional<NetworkPorts> networkPorts =
+                NetworkPortsSerializer.fromSlime(object.field(hostSpecNetworkPortsKey));
+        return new HostSpec(object.field(hostSpecHostNameKey).asString(), aliasesFromSlime(object), flavor, membership, version, networkPorts);
+    }
+
+    private static List<String> aliasesFromSlime(Inspector object) {
+        if ( ! object.field(aliasesKey).valid()) return Collections.emptyList();
+        List<String> aliases = new ArrayList<>();
+        object.field(aliasesKey).traverse((ArrayTraverser)(index, alias) -> aliases.add(alias.asString()));
+        return aliases;
+    }
+
+    private static Optional<Flavor> flavorFromSlime(Inspector object, Optional<NodeFlavors> nodeFlavors) {
+        if (object.field(flavorKey).valid() && nodeFlavors.isPresent() && nodeFlavors.get().exists(object.field(flavorKey).asString())) {
+            return nodeFlavors.get().getFlavor(object.field(flavorKey).asString());
+        }
+        else if (object.field(resourcesKey).valid()) {
+            Inspector resources = object.field(resourcesKey);
+            return Optional.of(new Flavor(new NodeResources(resources.field(vcpuKey).asDouble(),
+                                                            resources.field(memoryKey).asDouble(),
+                                                            resources.field(diskKey).asDouble(),
+                                                            diskSpeedFromSlime(resources.field(diskSpeedKey)))));
+        }
+        else {
+            return Optional.empty();
+        }
+    }
+
+    private static NodeResources.DiskSpeed diskSpeedFromSlime(Inspector diskSpeed) {
+        if ( ! diskSpeed.valid()) return NodeResources.DiskSpeed.fast; // TODO: Remove this line after June 2019
+        switch (diskSpeed.asString()) {
+            case "fast" : return NodeResources.DiskSpeed.fast;
+            case "slow" : return NodeResources.DiskSpeed.slow;
+            case "any" : return NodeResources.DiskSpeed.any;
+            default: throw new IllegalStateException("Illegal disk-speed value '" + diskSpeed.asString() + "'");
+        }
+    }
+
+    private static String diskSpeedToString(NodeResources.DiskSpeed diskSpeed) {
+        switch (diskSpeed) {
+            case fast : return "fast";
+            case slow : return "slow";
+            case any : return "any";
+            default: throw new IllegalStateException("Illegal disk-speed value '" + diskSpeed + "'");
+        }
+
+    }
+
+    private static ClusterMembership membershipFromSlime(Inspector object) {
+        return ClusterMembership.from(object.field(hostSpecMembershipKey).asString(),
+                                      com.yahoo.component.Version.fromString(object.field(hostSpecVespaVersionKey).asString()));
+    }
+
+    private static Optional<String> optionalString(Inspector inspector) {
+        if ( ! inspector.valid()) return Optional.empty();
+        return Optional.of(inspector.asString());
+    }
+}
diff --git a/config-provisioning/src/main/java/com/yahoo/config/provision/serialization/package-info.java b/config-provisioning/src/main/java/com/yahoo/config/provision/serialization/package-info.java
new file mode 100644
index 00000000000..440228b9d3e
--- /dev/null
+++ b/config-provisioning/src/main/java/com/yahoo/config/provision/serialization/package-info.java
@@ -0,0 +1,5 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+@ExportPackage
+package com.yahoo.config.provision.serialization;
+
+import com.yahoo.osgi.annotation.ExportPackage;
diff --git a/config-provisioning/src/test/java/com/yahoo/config/provision/AllocatedHostsTest.java b/config-provisioning/src/test/java/com/yahoo/config/provision/serialization/AllocatedHostsSerializerTest.java
index 737c1047197..44aa6ed59b5 100644
--- a/config-provisioning/src/test/java/com/yahoo/config/provision/AllocatedHostsTest.java
+++ b/config-provisioning/src/test/java/com/yahoo/config/provision/serialization/AllocatedHostsSerializerTest.java
@@ -1,7 +1,14 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.config.provision;
+package com.yahoo.config.provision.serialization;
 
 import com.yahoo.component.Version;
+import com.yahoo.config.provision.AllocatedHosts;
+import com.yahoo.config.provision.ClusterMembership;
+import com.yahoo.config.provision.Flavor;
+import com.yahoo.config.provision.HostSpec;
+import com.yahoo.config.provision.NetworkPorts;
+import com.yahoo.config.provision.NodeFlavors;
+import com.yahoo.config.provision.NodeResources;
 import com.yahoo.config.provisioning.FlavorsConfig;
 import org.junit.Test;
 
@@ -12,12 +19,14 @@ import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 
+import static com.yahoo.config.provision.serialization.AllocatedHostsSerializer.fromJson;
+import static com.yahoo.config.provision.serialization.AllocatedHostsSerializer.toJson;
 import static org.junit.Assert.assertEquals;
 
 /**
  * @author bratseth
  */
-public class AllocatedHostsTest {
+public class AllocatedHostsSerializerTest {
 
     @Test
     public void testAllocatedHostsSerialization() throws IOException {
@@ -29,7 +38,7 @@ public class AllocatedHostsTest {
         hosts.add(new HostSpec("with-aliases",
                                List.of("alias1", "alias2")));
         hosts.add(new HostSpec("allocated",
-                               Optional.of(ClusterMembership.from("container/test/0/0", com.yahoo.component.Version.fromString("6.73.1")))));
+                               Optional.of(ClusterMembership.from("container/test/0/0", Version.fromString("6.73.1")))));
         hosts.add(new HostSpec("flavor-from-resources-1",
                                Collections.emptyList(), new Flavor(new NodeResources(0.5, 3.1, 4))));
         hosts.add(new HostSpec("flavor-from-resources-2",
@@ -47,8 +56,7 @@ public class AllocatedHostsTest {
     }
 
     private void assertAllocatedHosts(AllocatedHosts expectedHosts, NodeFlavors configuredFlavors) throws IOException {
-        AllocatedHosts deserializedHosts = AllocatedHosts.fromJson(expectedHosts.toJson(),
-                                                                   Optional.of(configuredFlavors));
+        AllocatedHosts deserializedHosts = fromJson(toJson(expectedHosts), Optional.of(configuredFlavors));
 
         assertEquals(expectedHosts, deserializedHosts);
         for (HostSpec expectedHost : expectedHosts.getHosts()) {
@@ -69,7 +77,7 @@ public class AllocatedHostsTest {
         throw new IllegalArgumentException("No host " + hostname + " is present");
     }
 
-    public NodeFlavors configuredFlavorsFrom(String flavorName, double cpu, double mem, double disk, Flavor.Type type) {
+    private NodeFlavors configuredFlavorsFrom(String flavorName, double cpu, double mem, double disk, Flavor.Type type) {
         FlavorsConfig.Builder b = new FlavorsConfig.Builder();
         FlavorsConfig.Flavor.Builder flavor = new FlavorsConfig.Flavor.Builder();
         flavor.name(flavorName);
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.java b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.java
index e5552de41f5..110e73bcdf9 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.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.config.server.deploy;
 
+import com.yahoo.component.Version;
 import com.yahoo.config.application.api.ApplicationFile;
 import com.yahoo.config.application.api.ApplicationMetaData;
 import com.yahoo.config.application.api.ApplicationPackage;
@@ -9,7 +10,7 @@ import com.yahoo.config.application.api.FileRegistry;
 import com.yahoo.config.application.api.UnparsedConfigDefinition;
 import com.yahoo.config.model.application.provider.PreGeneratedFileRegistry;
 import com.yahoo.config.provision.AllocatedHosts;
-import com.yahoo.component.Version;
+import com.yahoo.config.provision.serialization.AllocatedHostsSerializer;
 import com.yahoo.io.reader.NamedReader;
 import com.yahoo.log.LogLevel;
 import com.yahoo.path.Path;
@@ -361,7 +362,9 @@ public class ZooKeeperClient {
     }
 
     public void write(AllocatedHosts hosts) throws IOException {
-        configCurator.putData(rootPath.append(ZKApplicationPackage.allocatedHostsNode).getAbsolute(), hosts.toJson());
+        configCurator.putData(
+                rootPath.append(ZKApplicationPackage.allocatedHostsNode).getAbsolute(),
+                AllocatedHostsSerializer.toJson(hosts));
     }
 
     public void write(Map<Version, FileRegistry> fileRegistryMap) {
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackage.java b/configserver/src/main/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackage.java
index 5c40f592a77..e013244c80c 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackage.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackage.java
@@ -3,19 +3,20 @@ package com.yahoo.vespa.config.server.zookeeper;
 
 import com.google.common.base.Joiner;
 import com.yahoo.component.Version;
+import com.yahoo.config.application.api.ApplicationFile;
 import com.yahoo.config.application.api.ApplicationMetaData;
+import com.yahoo.config.application.api.ApplicationPackage;
 import com.yahoo.config.application.api.ComponentInfo;
 import com.yahoo.config.application.api.FileRegistry;
 import com.yahoo.config.application.api.UnparsedConfigDefinition;
 import com.yahoo.config.codegen.DefParser;
-import com.yahoo.config.application.api.ApplicationFile;
-import com.yahoo.config.application.api.ApplicationPackage;
 import com.yahoo.config.model.application.provider.PreGeneratedFileRegistry;
-import com.yahoo.config.provision.NodeFlavors;
 import com.yahoo.config.provision.AllocatedHosts;
+import com.yahoo.config.provision.NodeFlavors;
+import com.yahoo.config.provision.serialization.AllocatedHostsSerializer;
 import com.yahoo.io.IOUtils;
-import com.yahoo.path.Path;
 import com.yahoo.io.reader.NamedReader;
+import com.yahoo.path.Path;
 import com.yahoo.vespa.config.ConfigDefinition;
 import com.yahoo.vespa.config.ConfigDefinitionBuilder;
 import com.yahoo.vespa.config.ConfigDefinitionKey;
@@ -69,7 +70,7 @@ public class ZKApplicationPackage implements ApplicationPackage {
      */
     private AllocatedHosts readAllocatedHosts(String allocatedHostsPath, Optional<NodeFlavors> nodeFlavors) {
         try {
-            return AllocatedHosts.fromJson(liveApp.getBytes(allocatedHostsPath), nodeFlavors);
+            return AllocatedHostsSerializer.fromJson(liveApp.getBytes(allocatedHostsPath), nodeFlavors);
         } catch (Exception e) {
             throw new RuntimeException("Unable to read allocated hosts", e);
         }
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java
index e01b2eccb35..918670d71f2 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java
@@ -13,9 +13,9 @@ import com.yahoo.config.model.application.provider.MockFileRegistry;
 import com.yahoo.config.provision.AllocatedHosts;
 import com.yahoo.config.provision.HostSpec;
 import com.yahoo.path.Path;
+import com.yahoo.vespa.config.server.zookeeper.ConfigCurator;
 import com.yahoo.vespa.config.server.zookeeper.ZKApplicationPackage;
 import com.yahoo.vespa.curator.mock.MockCurator;
-import com.yahoo.vespa.config.server.zookeeper.ConfigCurator;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Rule;
@@ -30,10 +30,11 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
+import static com.yahoo.config.provision.serialization.AllocatedHostsSerializer.fromJson;
 import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 
 /**
  * Unit tests for ZooKeeperClient.
@@ -199,7 +200,7 @@ public class ZooKeeperClientTest {
         Path hostsPath = app.append(ZKApplicationPackage.allocatedHostsNode);
         assertTrue(zk.exists(hostsPath.getAbsolute()));
         
-        AllocatedHosts deserialized = AllocatedHosts.fromJson(zk.getBytes(hostsPath.getAbsolute()), Optional.empty());
+        AllocatedHosts deserialized = fromJson(zk.getBytes(hostsPath.getAbsolute()), Optional.empty());
         assertEquals(hosts, deserialized.getHosts());
     }
 
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackageTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackageTest.java
index e8e2dd07756..8b8be1a27d7 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackageTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackageTest.java
@@ -1,27 +1,15 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.server.zookeeper;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.assertThat;
-
-import java.io.File;
-import java.io.IOException;
-import java.io.Reader;
-import java.util.Collections;
-import java.util.Optional;
-import java.util.regex.Pattern;
-
+import com.yahoo.component.Version;
 import com.yahoo.config.application.api.DeploymentSpec;
 import com.yahoo.config.model.deploy.DeployState;
+import com.yahoo.config.provision.AllocatedHosts;
 import com.yahoo.config.provision.Flavor;
 import com.yahoo.config.provision.HostSpec;
 import com.yahoo.config.provision.NodeFlavors;
-import com.yahoo.config.provision.AllocatedHosts;
-import com.yahoo.component.Version;
 import com.yahoo.config.provisioning.FlavorsConfig;
+import com.yahoo.io.IOUtils;
 import com.yahoo.path.Path;
 import com.yahoo.text.Utf8;
 import com.yahoo.vespa.curator.mock.MockCurator;
@@ -30,7 +18,19 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
-import com.yahoo.io.IOUtils;
+import java.io.File;
+import java.io.IOException;
+import java.io.Reader;
+import java.util.Collections;
+import java.util.Optional;
+import java.util.regex.Pattern;
+
+import static com.yahoo.config.provision.serialization.AllocatedHostsSerializer.toJson;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 
 public class ZKApplicationPackageTest {
 
@@ -77,7 +77,7 @@ public class ZKApplicationPackageTest {
         assertFalse(zkApp.getFileRegistries().containsKey(new Version(0, 0, 0)));
         assertThat(zkApp.getFileRegistries().get(goodVersion).fileSourceHost(), is("dummyfiles"));
         AllocatedHosts readInfo = zkApp.getAllocatedHosts().get();
-        assertThat(Utf8.toString(readInfo.toJson()), is(Utf8.toString(ALLOCATED_HOSTS.toJson())));
+        assertThat(Utf8.toString(toJson(readInfo)), is(Utf8.toString(toJson(ALLOCATED_HOSTS))));
         assertThat(readInfo.getHosts().iterator().next().flavor(), is(TEST_FLAVOR));
         assertEquals("6.0.1", readInfo.getHosts().iterator().next().version().get().toString());
         assertTrue(zkApp.getDeployment().isPresent());
@@ -90,7 +90,7 @@ public class ZKApplicationPackageTest {
         String metaData = "{\"deploy\":{\"user\":\"foo\",\"from\":\"bar\",\"timestamp\":1},\"application\":{\"name\":\"foo\",\"checksum\":\"abc\",\"generation\":4,\"previousActiveGeneration\":3}}";
         zk.putData("/0", ConfigCurator.META_ZK_PATH, metaData);
         zk.putData("/0/" + ZKApplicationPackage.fileRegistryNode + "/3.0.0", "dummyfiles");
-        zk.putData("/0/" + ZKApplicationPackage.allocatedHostsNode, ALLOCATED_HOSTS.toJson());
+        zk.putData("/0/" + ZKApplicationPackage.allocatedHostsNode, toJson(ALLOCATED_HOSTS));
     }
 
     private static class MockNodeFlavors extends NodeFlavors{