Use both xxhash64 and md5 for config payload in requests and responses

Chacking of equal config with hasEqualConfig() still uses only md5

26 files changed, 404 insertions, 158 deletions

diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
index 53a9f3f9f94..b1939ac23c6 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
@@ -11,6 +11,7 @@ import com.yahoo.config.subscription.FileSource;
 import com.yahoo.config.subscription.JarSource;
 import com.yahoo.config.subscription.RawSource;
 import com.yahoo.vespa.config.ConfigKey;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.vespa.config.TimingValues;
 import com.yahoo.vespa.config.protocol.DefContent;
 
@@ -40,31 +41,31 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
         private final T config;
         private final Long generation;
         private final boolean applyOnRestart;
-        private final PayloadChecksum payloadChecksum;
+        private final PayloadChecksums payloadChecksums;
 
         private ConfigState(boolean generationChanged,
                             Long generation,
                             boolean applyOnRestart,
                             boolean configChanged,
                             T config,
-                            PayloadChecksum payloadChecksum) {
+                            PayloadChecksums payloadChecksums) {
             this.generationChanged = generationChanged;
             this.generation = generation;
             this.applyOnRestart = applyOnRestart;
             this.configChanged = configChanged;
             this.config = config;
-            this.payloadChecksum = payloadChecksum;
+            this.payloadChecksums = payloadChecksums;
         }
 
-        private ConfigState(Long generation, T config, PayloadChecksum payloadChecksum) {
-            this(false, generation, false, false, config, payloadChecksum);
+        private ConfigState(Long generation, T config, PayloadChecksums payloadChecksums) {
+            this(false, generation, false, false, config, payloadChecksums);
         }
 
         private ConfigState() {
-            this(false, 0L, false, false, null, PayloadChecksum.empty());
+            this(false, 0L, false, false, null, PayloadChecksums.empty());
         }
 
-        private ConfigState<T> createUnchanged() {  return new ConfigState<>(generation, config, payloadChecksum); }
+        private ConfigState<T> createUnchanged() {  return new ConfigState<>(generation, config, payloadChecksums); }
 
         public boolean isConfigChanged() { return configChanged; }
 
@@ -76,7 +77,7 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
 
         public T getConfig() { return config; }
 
-        public PayloadChecksum getChecksum() { return payloadChecksum; }
+        public PayloadChecksums getChecksums() { return payloadChecksums; }
 
     }
 
@@ -195,8 +196,8 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
         return !prev.getGeneration().equals(requiredGen) || prev.isConfigChanged();
     }
 
-    void setConfig(Long generation, boolean applyOnRestart, T config, PayloadChecksum payloadChecksum) {
-        this.config.set(new ConfigState<>(true, generation, applyOnRestart, true, config, payloadChecksum));
+    void setConfig(Long generation, boolean applyOnRestart, T config, PayloadChecksums payloadChecksums) {
+        this.config.set(new ConfigState<>(true, generation, applyOnRestart, true, config, payloadChecksums));
     }
 
     /**
@@ -204,22 +205,22 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
      */
     protected void setConfigIncGen(T config) {
         ConfigState<T> prev = this.config.get();
-        this.config.set(new ConfigState<>(true, prev.getGeneration() + 1, prev.applyOnRestart(), true, config, prev.payloadChecksum));
+        this.config.set(new ConfigState<>(true, prev.getGeneration() + 1, prev.applyOnRestart(), true, config, prev.payloadChecksums));
     }
 
     protected void setConfigIfChanged(T config) {
         ConfigState<T> prev = this.config.get();
-        this.config.set(new ConfigState<>(true, prev.getGeneration(), prev.applyOnRestart(), !config.equals(prev.getConfig()), config, prev.payloadChecksum));
+        this.config.set(new ConfigState<>(true, prev.getGeneration(), prev.applyOnRestart(), !config.equals(prev.getConfig()), config, prev.payloadChecksums));
     }
 
     void setGeneration(Long generation) {
         ConfigState<T> prev = config.get();
-        this.config.set(new ConfigState<>(true, generation, prev.applyOnRestart(), prev.isConfigChanged(), prev.getConfig(), prev.payloadChecksum));
+        this.config.set(new ConfigState<>(true, generation, prev.applyOnRestart(), prev.isConfigChanged(), prev.getConfig(), prev.payloadChecksums));
     }
 
     void setApplyOnRestart(boolean applyOnRestart) {
         ConfigState<T> prev = config.get();
-        this.config.set(new ConfigState<>(prev.isGenerationChanged(), prev.getGeneration(), applyOnRestart, prev.isConfigChanged(), prev.getConfig(), prev.payloadChecksum));
+        this.config.set(new ConfigState<>(prev.isGenerationChanged(), prev.getGeneration(), applyOnRestart, prev.isConfigChanged(), prev.getConfig(), prev.payloadChecksums));
     }
 
     /**
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java
index 05d4a33c02a..e9a40539bf0 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/GenericJRTConfigSubscription.java
@@ -33,7 +33,7 @@ public class GenericJRTConfigSubscription extends JRTConfigSubscription<RawConfi
     @Override
     protected void setNewConfig(JRTClientConfigRequest jrtReq) {
         RawConfig rawConfig = RawConfig.createFromResponseParameters(jrtReq);
-        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsApplyOnRestart(), rawConfig, new PayloadChecksum(jrtReq.getNewConfigMd5()));
+        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsApplyOnRestart(), rawConfig, jrtReq.getNewChecksums());
         log.log(FINE, () -> "in setNewConfig, config=" + this.getConfigState().getConfig());
     }
 
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java
index b06f986555c..bb1a154d5d0 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java
@@ -111,7 +111,7 @@ public class JRTConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
         } catch (IllegalArgumentException e) {
             badConfigE = e;
         }
-        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsApplyOnRestart(), configInstance, new PayloadChecksum(jrtReq.getNewConfigMd5()));
+        setConfig(jrtReq.getNewGeneration(), jrtReq.responseIsApplyOnRestart(), configInstance, jrtReq.getNewChecksums());
         if (badConfigE != null) {
             throw new IllegalArgumentException("Bad config from jrt", badConfigE);
         }
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java
index b7198b0c694..4a55c046f13 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/JarConfigSubscription.java
@@ -9,6 +9,7 @@ import com.yahoo.config.subscription.ConfigSubscriber;
 import com.yahoo.io.IOUtils;
 import com.yahoo.vespa.config.ConfigKey;
 import com.yahoo.vespa.config.ConfigPayload;
+import com.yahoo.vespa.config.PayloadChecksums;
 
 import java.io.IOException;
 import java.io.InputStreamReader;
@@ -63,7 +64,7 @@ public class JarConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
             } catch (IOException e) {
                 throw new ConfigurationRuntimeException(e);
             }
-            setConfig(0L, false, config, PayloadChecksum.empty());
+            setConfig(0L, false, config, PayloadChecksums.empty());
             try {
                 jarFile.close();
             } catch (IOException e) {
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java b/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java
index bed7a0fa3c4..e9e7f3e7bce 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/MockConnection.java
@@ -7,9 +7,9 @@ import com.yahoo.jrt.Supervisor;
 import com.yahoo.vespa.config.ConfigPayload;
 import com.yahoo.vespa.config.Connection;
 import com.yahoo.vespa.config.ConnectionPool;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.vespa.config.protocol.JRTServerConfigRequestV3;
 import com.yahoo.vespa.config.protocol.Payload;
-import com.yahoo.vespa.config.util.ConfigUtils;
 
 /**
  * For unit testing
@@ -96,7 +96,7 @@ public class MockConnection implements ConnectionPool, Connection {
             JRTServerConfigRequestV3 jrtReq = JRTServerConfigRequestV3.createFromRequest(request);
             Payload payload = Payload.from(ConfigPayload.empty());
             long generation = 1;
-            jrtReq.addOkResponse(payload, generation, false, ConfigUtils.getMd5(payload.getData()));
+            jrtReq.addOkResponse(payload, generation, false, PayloadChecksums.fromPayload(payload));
         }
 
     }
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java
index 91b674da3d2..8d5e7839086 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/RawConfigSubscription.java
@@ -7,6 +7,7 @@ import com.yahoo.config.subscription.ConfigInterruptedException;
 import com.yahoo.config.subscription.ConfigSubscriber;
 import com.yahoo.vespa.config.ConfigKey;
 import com.yahoo.vespa.config.ConfigPayload;
+import com.yahoo.vespa.config.PayloadChecksums;
 
 import java.util.Arrays;
 
@@ -35,7 +36,7 @@ public class RawConfigSubscription<T extends ConfigInstance> extends ConfigSubsc
         if (payload == null) {
             payload = inputPayload;
             ConfigPayload configPayload = new CfgConfigPayloadBuilder().deserialize(Arrays.asList(payload.split("\n")));
-            setConfig(0L, false, configPayload.toInstance(configClass, key.getConfigId()), PayloadChecksum.empty());
+            setConfig(0L, false, configPayload.toInstance(configClass, key.getConfigId()), PayloadChecksums.empty());
             return true;
         }
         try {
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/PayloadChecksum.java b/config/src/main/java/com/yahoo/vespa/config/PayloadChecksum.java
index 93b85aaabd0..17f486e15d1 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/PayloadChecksum.java
+++ b/config/src/main/java/com/yahoo/vespa/config/PayloadChecksum.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.config.subscription.impl;
+package com.yahoo.vespa.config;
 
+import java.util.Objects;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -17,13 +18,13 @@ public class PayloadChecksum {
     private final String checksum;
     private final Type type;
 
-    public PayloadChecksum(String checksum) {
+    public PayloadChecksum(String checksum, Type type) {
         this.checksum = checksum;
-        this.type = Type.MD5;
+        this.type = type;
     }
 
-    public static PayloadChecksum empty() {
-        return new PayloadChecksum("");
+    public static PayloadChecksum empty(Type type) {
+        return new PayloadChecksum("", type);
     }
 
     public String asString() { return checksum; }
@@ -45,4 +46,21 @@ public class PayloadChecksum {
         return m.matches();
     }
 
+    @Override
+    public int hashCode() {
+        return Objects.hash(checksum, type);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        PayloadChecksum that = (PayloadChecksum) o;
+        return Objects.equals(checksum, that.checksum) && type == that.type;
+    }
+
+    @Override
+    public String toString() {
+        return type.name() + ":" + checksum;
+    }
 }
diff --git a/config/src/main/java/com/yahoo/vespa/config/PayloadChecksums.java b/config/src/main/java/com/yahoo/vespa/config/PayloadChecksums.java
new file mode 100644
index 00000000000..1558771bd58
--- /dev/null
+++ b/config/src/main/java/com/yahoo/vespa/config/PayloadChecksums.java
@@ -0,0 +1,83 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.config;
+
+import com.yahoo.vespa.config.protocol.Payload;
+import com.yahoo.vespa.config.util.ConfigUtils;
+
+import java.util.Arrays;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
+
+/**
+ * Checksums for config payload, typically 1 for each PayloadChecksum type (md5 and xxhash64).
+ * Initialized with empty checksum for each existing type.
+ *
+ * @author hmusum
+ */
+public class PayloadChecksums {
+
+    private final Map<PayloadChecksum.Type, PayloadChecksum> checksums = new LinkedHashMap<>();
+
+    private PayloadChecksums() {
+        Arrays.stream(PayloadChecksum.Type.values()).forEach(type -> checksums.put(type, PayloadChecksum.empty(type)));
+    }
+
+    public static PayloadChecksums empty() { return new PayloadChecksums(); }
+
+    public static PayloadChecksums from(PayloadChecksum... checksums) {
+        PayloadChecksums payloadChecksums = new PayloadChecksums();
+        Arrays.stream(checksums).forEach(payloadChecksums::add);
+        return payloadChecksums;
+    }
+
+    public static PayloadChecksums from(String configMd5, String configXxhash64) {
+        return new PayloadChecksums()
+                .add(new PayloadChecksum(configMd5, MD5))
+                .add(new PayloadChecksum(configXxhash64, XXHASH64));
+    }
+
+    public static PayloadChecksums fromPayload(Payload payload) {
+        return new PayloadChecksums()
+                .add(new PayloadChecksum(ConfigUtils.getMd5(payload.getData()), MD5))
+                .add(new PayloadChecksum(ConfigUtils.getXxhash64(payload.getData()), XXHASH64));
+    }
+
+    private PayloadChecksums add(PayloadChecksum checksum) {
+        checksums.put(checksum.type(), checksum);
+        return this;
+    }
+
+    public PayloadChecksum getForType(PayloadChecksum.Type type) {
+        return checksums.get(type);
+    }
+
+    public boolean valid() {
+        return checksums.values().stream().allMatch(PayloadChecksum::valid);
+    }
+
+    @Override
+    public String toString() {
+        return checksums.values().stream()
+                        .map(checksum -> checksum.type().name() + ":" + checksum.asString())
+                        .collect(Collectors.joining(","));
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        PayloadChecksums that = (PayloadChecksums) o;
+        return Objects.equals(checksums, that.checksums);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(checksums);
+    }
+
+}
diff --git a/config/src/main/java/com/yahoo/vespa/config/RawConfig.java b/config/src/main/java/com/yahoo/vespa/config/RawConfig.java
index 028e84e4c29..52f2e0798f6 100755
--- a/config/src/main/java/com/yahoo/vespa/config/RawConfig.java
+++ b/config/src/main/java/com/yahoo/vespa/config/RawConfig.java
@@ -1,4 +1,4 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config;
 
 import com.yahoo.config.ConfigInstance;
@@ -28,7 +28,7 @@ public class RawConfig extends ConfigInstance {
     private final List<String> defContent;
     private final Payload payload;
     private final int errorCode;
-    private final String configMd5;
+    private final PayloadChecksums payloadChecksums;
     private final Optional<VespaVersion> vespaVersion;
     private long generation;
     private boolean applyOnRestart;
@@ -40,29 +40,28 @@ public class RawConfig extends ConfigInstance {
      * @param defMd5  The md5 sum of the .def-file.
      */
     public RawConfig(ConfigKey<?> key, String defMd5) {
-        this(key, defMd5, null, "", 0L, false, 0, Collections.emptyList(), Optional.empty());
+        this(key, defMd5, null, PayloadChecksums.empty(), 0L, false, 0, Collections.emptyList(), Optional.empty());
     }
 
-    public RawConfig(ConfigKey<?> key, String defMd5, Payload payload, String configMd5, long generation,
-                     boolean applyOnRestart, List<String> defContent,
-                     Optional<VespaVersion> vespaVersion) {
-        this(key, defMd5, payload, configMd5, generation, applyOnRestart, 0, defContent, vespaVersion);
+    public RawConfig(ConfigKey<?> key, String defMd5, Payload payload, PayloadChecksums payloadChecksums, long generation,
+                     boolean applyOnRestart, List<String> defContent, Optional<VespaVersion> vespaVersion) {
+        this(key, defMd5, payload, payloadChecksums, generation, applyOnRestart, 0, defContent, vespaVersion);
     }
 
     /** Copy constructor */
     public RawConfig(RawConfig rawConfig) {
-        this(rawConfig.key, rawConfig.defMd5, rawConfig.payload, rawConfig.configMd5,
+        this(rawConfig.key, rawConfig.defMd5, rawConfig.payload, rawConfig.payloadChecksums,
              rawConfig.generation, rawConfig.applyOnRestart,
              rawConfig.errorCode, rawConfig.defContent, rawConfig.getVespaVersion());
     }
 
-    public RawConfig(ConfigKey<?> key, String defMd5, Payload payload, String configMd5, long generation,
+    public RawConfig(ConfigKey<?> key, String defMd5, Payload payload, PayloadChecksums payloadChecksums, long generation,
                      boolean applyOnRestart, int errorCode, List<String> defContent,
                      Optional<VespaVersion> vespaVersion) {
         this.key = key;
         this.defMd5 = ConfigUtils.getDefMd5FromRequest(defMd5, defContent);
         this.payload = payload;
-        this.configMd5 = configMd5;
+        this.payloadChecksums = payloadChecksums;
         this.generation = generation;
         this.applyOnRestart = applyOnRestart;
         this.errorCode = errorCode;
@@ -79,7 +78,7 @@ public class RawConfig extends ConfigInstance {
         return new RawConfig(req.getConfigKey(),
                              ConfigUtils.getDefMd5(req.getDefContent().asList()),
                              req.getNewPayload(),
-                             req.getNewConfigMd5(),
+                             req.getRequestConfigChecksums(),
                              req.getNewGeneration(),
                              req.responseIsApplyOnRestart(),
                              0,
@@ -96,7 +95,7 @@ public class RawConfig extends ConfigInstance {
         return new RawConfig(req.getConfigKey(),
                              ConfigUtils.getDefMd5(req.getDefContent().asList()),
                              Payload.from(new Utf8String(""), CompressionInfo.uncompressed()),
-                             req.getRequestConfigMd5(),
+                             req.getRequestConfigChecksums(),
                              req.getRequestGeneration(),
                              req.applyOnRestart(),
                              0,
@@ -113,7 +112,7 @@ public class RawConfig extends ConfigInstance {
 
     public String getConfigId() { return key.getConfigId(); }
 
-    public String getConfigMd5() { return configMd5; }
+    public String getConfigMd5() { return payloadChecksums.getForType(PayloadChecksum.Type.MD5).asString(); }
 
     public String getDefMd5() { return defMd5; }
 
@@ -133,6 +132,8 @@ public class RawConfig extends ConfigInstance {
 
     public Optional<VespaVersion> getVespaVersion() { return vespaVersion; }
 
+    public PayloadChecksums getPayloadChecksums() { return payloadChecksums; }
+
     /**
      * Returns true if this config is equal to the config (same payload md5) in the given request.
      *
@@ -174,11 +175,7 @@ public class RawConfig extends ConfigInstance {
         // while non-zero and equal error codes means configs are equal.
         if (isError()) return true;
         if (generation != other.generation) return false;
-        if (configMd5 != null) {
-            return configMd5.equals(other.configMd5);
-        } else {
-            return (other.configMd5 == null);
-        }
+        return (payloadChecksums.equals(((RawConfig) o).payloadChecksums));
     }
 
     @Override
@@ -194,9 +191,7 @@ public class RawConfig extends ConfigInstance {
         if (! isError()) {
             // configMd5 and generation only matter when the RawConfig is not an error.
             hash = 31 * hash + (int)(generation ^(generation >>>32));
-            if (configMd5 != null) {
-                hash = 31 * hash + configMd5.hashCode();
-            }
+            hash = 31 * hash + payloadChecksums.hashCode();
         }
         return hash;
     }
@@ -210,7 +205,7 @@ public class RawConfig extends ConfigInstance {
         sb.append(",");
         sb.append(key.getConfigId());
         sb.append(",");
-        sb.append(getConfigMd5());
+        sb.append(payloadChecksums);
         sb.append(",");
         sb.append(getGeneration());
         sb.append(",");
diff --git a/config/src/main/java/com/yahoo/vespa/config/benchmark/LoadTester.java b/config/src/main/java/com/yahoo/vespa/config/benchmark/LoadTester.java
index adb27f37413..345118b5fd4 100644
--- a/config/src/main/java/com/yahoo/vespa/config/benchmark/LoadTester.java
+++ b/config/src/main/java/com/yahoo/vespa/config/benchmark/LoadTester.java
@@ -2,6 +2,7 @@
 package com.yahoo.vespa.config.benchmark;
 
 import com.yahoo.collections.Tuple2;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.io.IOUtils;
 import com.yahoo.jrt.Spec;
 import com.yahoo.jrt.Supervisor;
@@ -256,7 +257,7 @@ public class LoadTester {
 
             final long serverTimeout = 1000;
             return JRTClientConfigRequestV3.createWithParams(fullKey, DefContent.fromList(List.of(defContent.second)),
-                                                             ConfigUtils.getCanonicalHostName(), "",
+                                                             ConfigUtils.getCanonicalHostName(), PayloadChecksums.empty(),
                                                              0, serverTimeout, Trace.createDummy(),
                                                              compressionType, Optional.empty());
         }
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/ConfigResponse.java b/config/src/main/java/com/yahoo/vespa/config/protocol/ConfigResponse.java
index f6fce56c227..98fc7f7a50e 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/ConfigResponse.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/ConfigResponse.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.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.text.AbstractUtf8Array;
 
 import java.io.IOException;
@@ -36,4 +37,6 @@ public interface ConfigResponse {
 
     CompressionInfo getCompressionInfo();
 
+    PayloadChecksums getPayloadChecksums();
+
 }
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequest.java b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequest.java
index 8535cc23225..9d3b87574f3 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequest.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequest.java
@@ -1,6 +1,8 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksums;
+
 /**
  * Interface for config requests used by clients.
  *
@@ -57,13 +59,20 @@ public interface JRTClientConfigRequest extends JRTConfigRequest {
     boolean responseIsApplyOnRestart();
 
     /**
-     * Get the config md5 of the config returned by the server. Return an empty string if no response has been returned.
+     * Gets the config md5 of the config returned by the server. Returns an empty string if no response has been returned.
      *
      * @return a config md5.
      */
     String getNewConfigMd5();
 
     /**
+     * Gets the config checksums of the config returned by the server. Returns an empty string if no response has been returned.
+     *
+     * @return a config checksum.
+     */
+    PayloadChecksums getNewChecksums();
+
+    /**
      * Test whether or not the response contains an updated config or not.
      * False if no response has been returned.
      *
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequestV3.java b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequestV3.java
index f5b558550e4..a6271b159ef 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequestV3.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTClientConfigRequestV3.java
@@ -1,9 +1,10 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.protocol;
 
 import com.yahoo.config.ConfigInstance;
 import com.yahoo.config.subscription.impl.ConfigSubscription;
 import com.yahoo.config.subscription.impl.JRTConfigSubscription;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.jrt.Request;
 import com.yahoo.jrt.StringValue;
 import com.yahoo.slime.JsonFormat;
@@ -38,7 +39,7 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
     protected JRTClientConfigRequestV3(ConfigKey<?> key,
                                        String hostname,
                                        DefContent defSchema,
-                                       String configMd5,
+                                       PayloadChecksums payloadChecksums,
                                        long generation,
                                        long timeout,
                                        Trace trace,
@@ -47,7 +48,7 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
         Slime data = SlimeRequestData.encodeRequest(key,
                                                     hostname,
                                                     defSchema,
-                                                    configMd5,
+                                                    payloadChecksums,
                                                     generation,
                                                     timeout,
                                                     trace,
@@ -97,7 +98,7 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
         return new JRTClientConfigRequestV3(getConfigKey(),
                 getClientHostName(),
                 getDefContent(),
-                isError() ? getRequestConfigMd5() : newConfMd5(),
+                isError() ? getRequestConfigChecksums() : newConfigChecksums(),
                 isError() ? getRequestGeneration() : newGen(),
                 timeout,
                 Trace.createNew(),
@@ -113,7 +114,7 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
         return createWithParams(sub.getKey(),
                                 sub.getDefContent(),
                                 ConfigUtils.getCanonicalHostName(),
-                                configState.getChecksum().asString(),
+                                configState.getChecksums(),
                                 configState.getGeneration(),
                                 sub.timingValues().getSubscribeTimeout(),
                                 trace,
@@ -128,34 +129,34 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
                                                        Optional<VespaVersion> vespaVersion) {
         String hostname = ConfigUtils.getCanonicalHostName();
         return createWithParams(config.getKey(),
-                DefContent.fromList(config.getDefContent()),
-                hostname,
-                config.getConfigMd5(),
-                config.getGeneration(),
-                serverTimeout,
-                trace,
-                compressionType,
-                vespaVersion);
+                                DefContent.fromList(config.getDefContent()),
+                                hostname,
+                                config.getPayloadChecksums(),
+                                config.getGeneration(),
+                                serverTimeout,
+                                trace,
+                                compressionType,
+                                vespaVersion);
     }
 
     public static JRTClientConfigRequest createWithParams(ConfigKey<?> reqKey,
                                                           DefContent defContent,
                                                           String hostname,
-                                                          String configMd5,
+                                                          PayloadChecksums payloadChecksums,
                                                           long generation,
                                                           long serverTimeout,
                                                           Trace trace,
                                                           CompressionType compressionType,
                                                           Optional<VespaVersion> vespaVersion) {
         return new JRTClientConfigRequestV3(reqKey,
-                hostname,
-                defContent,
-                configMd5,
-                generation,
-                serverTimeout,
-                trace,
-                compressionType,
-                vespaVersion);
+                                            hostname,
+                                            defContent,
+                                            payloadChecksums,
+                                            generation,
+                                            serverTimeout,
+                                            trace,
+                                            compressionType,
+                                            vespaVersion);
     }
 
     @Override
@@ -177,7 +178,7 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
                 .append(",").append(getTimeout())
                 .append(",").append(getVespaVersion().map(VespaVersion::toString).orElse(""))
                 .append("'\n");
-        sb.append("response='").append(getNewConfigMd5())
+                 sb.append("response='").append(getNewChecksums())
                 .append(",").append(getNewGeneration())
                 .append(",").append(responseIsApplyOnRestart())
                 .append("'\n");
@@ -221,6 +222,12 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
         return requestData.getTimeout();
     }
 
+    protected PayloadChecksums newConfigChecksums() {
+        PayloadChecksums newChecksum = getNewChecksums();
+        if (PayloadChecksums.empty().equals(newChecksum)) return getRequestConfigChecksums();
+        return newChecksum;
+    }
+
     protected String newConfMd5() {
         String newMd5 = getNewConfigMd5();
         if ("".equals(newMd5)) return getRequestConfigMd5();
@@ -264,6 +271,10 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
         return requestData.getRequestDefMd5();
     }
 
+    public PayloadChecksums getRequestConfigChecksums() {
+        return requestData.getRequestConfigChecksums();
+    }
+
     @Override
     public boolean validateResponse() {
         if (request.isError()) {
@@ -285,7 +296,12 @@ public class JRTClientConfigRequestV3 implements JRTClientConfigRequest {
 
     @Override
     public String getNewConfigMd5() {
-        return responseData.getResponseConfigMd5();
+        return responseData.getResponseConfigMd5().asString();
+    }
+
+    @Override
+    public PayloadChecksums getNewChecksums() {
+        return responseData.getResponseConfigChecksums();
     }
 
     @Override
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTConfigRequest.java b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTConfigRequest.java
index 5b8f040b8e3..0fc751dc49f 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTConfigRequest.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTConfigRequest.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.jrt.Request;
 import com.yahoo.vespa.config.ConfigKey;
 
@@ -44,6 +45,14 @@ public interface JRTConfigRequest {
 
     /**
      * Returns the generation of the requested config. If none has been given, 0 should be returned.
+     * Returns the checksum of the config request. Return an empty string if no response has been returned.
+     *
+     * @return a config checksum.
+     */
+    PayloadChecksums getRequestConfigChecksums();
+
+    /**
+     * Returns the generation of the requested config. If none has been given, 0 should be returned.
      *
      * @return the generation in the request.
      */
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequest.java b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequest.java
index abc2b0b4473..41106e138b7 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequest.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequest.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.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.vespa.config.GetConfigRequest;
 
 /**
@@ -34,9 +35,9 @@ public interface JRTServerConfigRequest extends JRTConfigRequest, GetConfigReque
      * @param generation The config generation of the given payload.
      * @param applyOnRestart true if this config should only be applied on the next restart,
      *                       false if it should be applied right away
-     * @param configMd5 The md5sum of the given payload.
+     * @param payloadChecksums checksums of the given payload.
      */
-    void addOkResponse(Payload payload, long generation, boolean applyOnRestart, String configMd5);
+    void addOkResponse(Payload payload, long generation, boolean applyOnRestart, PayloadChecksums payloadChecksums);
 
     /**
      * Get the current config md5 of the client config.
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequestV3.java b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequestV3.java
index e0a5b23a6d4..fbb52e81679 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequestV3.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/JRTServerConfigRequestV3.java
@@ -3,6 +3,7 @@ package com.yahoo.vespa.config.protocol;
 
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonGenerator;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.jrt.DataValue;
 import com.yahoo.jrt.Request;
 import com.yahoo.jrt.StringValue;
@@ -18,6 +19,9 @@ import java.nio.ByteBuffer;
 import java.util.Optional;
 import java.util.logging.Logger;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
+
 /**
  * The V3 config protocol implemented on the server side. The V3 protocol uses 2 fields:
  *
@@ -68,9 +72,9 @@ public class JRTServerConfigRequestV3 implements JRTServerConfigRequest {
     }
 
     @Override
-    public void addOkResponse(Payload payload, long generation, boolean applyOnRestart, String configMd5) {
+    public void addOkResponse(Payload payload, long generation, boolean applyOnRestart, PayloadChecksums payloadChecksums) {
         this.applyOnRestart = applyOnRestart;
-        boolean changedConfig = !configMd5.equals(getRequestConfigMd5());
+        boolean changedConfig = !payloadChecksums.equals(getRequestConfigChecksums());
         boolean changedConfigAndNewGeneration = changedConfig && ConfigUtils.isGenerationNewer(generation, getRequestGeneration());
         Payload responsePayload = payload.withCompression(getCompressionType());
         ByteArrayOutputStream byteArrayOutputStream = new NoCopyByteArrayOutputStream(4096);
@@ -78,7 +82,8 @@ public class JRTServerConfigRequestV3 implements JRTServerConfigRequest {
             JsonGenerator jsonGenerator = createJsonGenerator(byteArrayOutputStream);
             jsonGenerator.writeStartObject();
             addCommonReturnValues(jsonGenerator);
-            setResponseField(jsonGenerator, SlimeResponseData.RESPONSE_CONFIG_MD5, configMd5);
+            setResponseField(jsonGenerator, SlimeResponseData.RESPONSE_CONFIG_MD5, payloadChecksums.getForType(MD5).asString());
+            setResponseField(jsonGenerator, SlimeResponseData.RESPONSE_CONFIG_XXHASH64, payloadChecksums.getForType(XXHASH64).asString());
             setResponseField(jsonGenerator, SlimeResponseData.RESPONSE_CONFIG_GENERATION, generation);
             setResponseField(jsonGenerator, SlimeResponseData.RESPONSE_APPLY_ON_RESTART, applyOnRestart);
             jsonGenerator.writeObjectFieldStart(SlimeResponseData.RESPONSE_COMPRESSION_INFO);
@@ -194,6 +199,8 @@ public class JRTServerConfigRequestV3 implements JRTServerConfigRequest {
     @Override
     public String getRequestDefMd5() { return requestData.getRequestDefMd5(); }
 
+    public PayloadChecksums getRequestConfigChecksums() { return requestData.getRequestConfigChecksums(); }
+
     private void addErrorResponse(int errorCode) {
         addErrorResponse(errorCode, ErrorCode.getName(errorCode));
     }
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/RequestValidation.java b/config/src/main/java/com/yahoo/vespa/config/protocol/RequestValidation.java
index 7db15844e8b..9cd59798ecd 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/RequestValidation.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/RequestValidation.java
@@ -1,7 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.protocol;
 
-import com.yahoo.config.subscription.impl.PayloadChecksum;
+import com.yahoo.vespa.config.PayloadChecksum;
 import com.yahoo.vespa.config.ConfigDefinition;
 import com.yahoo.vespa.config.ConfigKey;
 import com.yahoo.vespa.config.ErrorCode;
@@ -9,6 +9,7 @@ import com.yahoo.vespa.config.ErrorCode;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
 import static java.util.logging.Level.INFO;
 
 /**
@@ -29,12 +30,12 @@ public class RequestValidation {
             log.log(INFO, "Illegal name space '" + key.getNamespace() + "'");
             return ErrorCode.ILLEGAL_NAME_SPACE;
         }
-        if (!(new PayloadChecksum(request.getRequestDefMd5()).valid())) {
+        if (!(new PayloadChecksum(request.getRequestDefMd5(), MD5).valid())) {
             log.log(INFO, "Illegal checksum '" + key.getNamespace() + "'");
             return ErrorCode.ILLEGAL_DEF_MD5;  // TODO: Use ILLEGAL_DEF_CHECKSUM
         }
-        if (!new PayloadChecksum(request.getRequestConfigMd5()).valid()) {
-            log.log(INFO, "Illegal config checksum '" + request.getRequestConfigMd5() + "'");
+        if (! request.getRequestConfigChecksums().valid()) {
+            log.log(INFO, "Illegal config checksum '" + request.getRequestConfigChecksums() + "'");
             return ErrorCode.ILLEGAL_CONFIG_MD5; // TODO: Use ILLEGAL_CONFIG_CHECKSUM
         }
         if (!RequestValidation.verifyGeneration(request.getRequestGeneration())) {
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeConfigResponse.java b/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeConfigResponse.java
index 1ccf6e367fc..8d08717942b 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeConfigResponse.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeConfigResponse.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.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.text.AbstractUtf8Array;
 import com.yahoo.vespa.config.ConfigPayload;
 
@@ -8,6 +9,8 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+
 /**
  * Class for serializing config responses based on {@link com.yahoo.slime.Slime} implementing the {@link ConfigResponse} interface.
  *
@@ -19,25 +22,42 @@ public class SlimeConfigResponse implements ConfigResponse {
     private final CompressionInfo compressionInfo;
     private final long generation;
     private final boolean applyOnRestart;
-    private final String configMd5;
+    private final PayloadChecksums payloadChecksums;
+
+    public static SlimeConfigResponse fromConfigPayload(ConfigPayload payload,
+                                                        long generation,
+                                                        boolean applyOnRestart,
+                                                        PayloadChecksums payloadChecksums) {
+        AbstractUtf8Array data = payload.toUtf8Array(true);
+        return new SlimeConfigResponse(data,
+                                       generation,
+                                       applyOnRestart,
+                                       payloadChecksums,
+                                       CompressionInfo.create(CompressionType.UNCOMPRESSED, data.getByteLength()));
+    }
 
-    public static SlimeConfigResponse fromConfigPayload(ConfigPayload payload, long generation,
-                                                        boolean applyOnRestart, String configMd5) {
+    // TODO: Legacy method, remove when not used anymore
+    public static SlimeConfigResponse fromConfigPayload(ConfigPayload payload,
+                                                        long generation,
+                                                        boolean applyOnRestart,
+                                                        String configMd5) {
         AbstractUtf8Array data = payload.toUtf8Array(true);
-        return new SlimeConfigResponse(data, generation, applyOnRestart,
-                                       configMd5,
+        return new SlimeConfigResponse(data,
+                                       generation,
+                                       applyOnRestart,
+                                       PayloadChecksums.from(configMd5, ""),
                                        CompressionInfo.create(CompressionType.UNCOMPRESSED, data.getByteLength()));
     }
 
     public SlimeConfigResponse(AbstractUtf8Array payload,
                                long generation,
                                boolean applyOnRestart,
-                               String configMd5,
+                               PayloadChecksums payloadChecksums,
                                CompressionInfo compressionInfo) {
         this.payload = payload;
         this.generation = generation;
         this.applyOnRestart = applyOnRestart;
-        this.configMd5 = configMd5;
+        this.payloadChecksums = payloadChecksums;
         this.compressionInfo = compressionInfo;
     }
 
@@ -56,7 +76,7 @@ public class SlimeConfigResponse implements ConfigResponse {
 
     @Override
     public String getConfigMd5() {
-        return configMd5;
+        return payloadChecksums.getForType(MD5).asString();
     }
 
     @Override
@@ -68,11 +88,13 @@ public class SlimeConfigResponse implements ConfigResponse {
     @Override
     public String toString() {
         return "generation=" + generation +  "\n" +
-                "configmd5=" + configMd5 +  "\n" +
+                "checksums=" + payloadChecksums +  "\n" +
                 Payload.from(payload, compressionInfo).withCompression(CompressionType.UNCOMPRESSED);
     }
 
     @Override
     public CompressionInfo getCompressionInfo() { return compressionInfo; }
 
+    @Override
+    public PayloadChecksums getPayloadChecksums() { return payloadChecksums; }
 }
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeRequestData.java b/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeRequestData.java
index b885623a78b..679298bac73 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeRequestData.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeRequestData.java
@@ -1,6 +1,8 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksum;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.jrt.Request;
 import com.yahoo.slime.Cursor;
 import com.yahoo.slime.Inspector;
@@ -11,6 +13,9 @@ import com.yahoo.vespa.config.util.ConfigUtils;
 
 import java.util.Optional;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
+
 /**
  * Contains slime request data objects. Provides methods for reading various fields from slime request data.
  * All data is read lazily.
@@ -27,6 +32,7 @@ class SlimeRequestData {
     private static final String REQUEST_CLIENT_HOSTNAME = "clientHostname";
     private static final String REQUEST_CURRENT_GENERATION = "currentGeneration";
     private static final String REQUEST_CONFIG_MD5 = "configMD5";
+    private static final String REQUEST_CONFIG_XXHASH64 = "configXxhash64";
     private static final String REQUEST_TRACE = "trace";
     private static final String REQUEST_TIMEOUT = "timeout";
     private static final String REQUEST_DEF_MD5 = "defMD5";
@@ -79,6 +85,17 @@ class SlimeRequestData {
 
     String getRequestDefMd5() { return getRequestField(REQUEST_DEF_MD5).asString(); }
 
+    PayloadChecksum getRequestConfigXxhash64() {
+        Inspector xxhash64Field = getRequestField(REQUEST_CONFIG_XXHASH64);
+        return xxhash64Field.valid()
+                ? new PayloadChecksum(xxhash64Field.asString(), XXHASH64)
+                : PayloadChecksum.empty(XXHASH64);
+    }
+
+    PayloadChecksums getRequestConfigChecksums() {
+        return PayloadChecksums.from(getRequestConfigMd5(), getRequestConfigXxhash64().asString());
+    }
+
     long getRequestGeneration() {
         return getRequestField(REQUEST_CURRENT_GENERATION).asLong();
     }
@@ -86,7 +103,7 @@ class SlimeRequestData {
     static Slime encodeRequest(ConfigKey<?> key,
                                String hostname,
                                DefContent defSchema,
-                               String configMd5,
+                               PayloadChecksums payloadChecksums,
                                long generation,
                                long timeout,
                                Trace trace,
@@ -102,7 +119,8 @@ class SlimeRequestData {
         request.setString(REQUEST_CLIENT_CONFIGID, key.getConfigId());
         request.setString(REQUEST_CLIENT_HOSTNAME, hostname);
         defSchema.serialize(request.setArray(REQUEST_DEF_CONTENT));
-        request.setString(REQUEST_CONFIG_MD5, configMd5);
+        request.setString(REQUEST_CONFIG_MD5, payloadChecksums.getForType(MD5).asString());
+        request.setString(REQUEST_CONFIG_XXHASH64, payloadChecksums.getForType(XXHASH64).asString());
         request.setLong(REQUEST_CURRENT_GENERATION, generation);
         request.setLong(REQUEST_TIMEOUT, timeout);
         request.setString(REQUEST_COMPRESSION_TYPE, compressionType.name());
diff --git a/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeResponseData.java b/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeResponseData.java
index cc98587456c..965622adaa5 100644
--- a/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeResponseData.java
+++ b/config/src/main/java/com/yahoo/vespa/config/protocol/SlimeResponseData.java
@@ -1,11 +1,16 @@
 // 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.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksum;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.jrt.Request;
 import com.yahoo.slime.Inspector;
 import com.yahoo.slime.Slime;
 import com.yahoo.slime.SlimeUtils;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
+
 /**
  * Contains response data for a slime response and methods for decoding the response data that
  * are common to all {@link Slime} based config requests.
@@ -22,6 +27,7 @@ class SlimeResponseData {
     static final String RESPONSE_CLIENT_HOSTNAME = "clientHostname";
     static final String RESPONSE_TRACE = "trace";
     static final String RESPONSE_CONFIG_MD5 = "configMD5";
+    static final String RESPONSE_CONFIG_XXHASH64 = "configXxhash64";
     static final String RESPONSE_CONFIG_GENERATION = "generation";
     static final String RESPONSE_APPLY_ON_RESTART = "applyOnRestart";
     static final String RESPONSE_COMPRESSION_INFO = "compressionInfo";
@@ -58,9 +64,25 @@ class SlimeResponseData {
         return trace.valid() ? Trace.fromSlime(trace) : Trace.createDummy();
     }
 
-    String getResponseConfigMd5() {
-        Inspector inspector = getResponseField(RESPONSE_CONFIG_MD5);
-        return inspector.valid() ? inspector.asString() : "";
+    PayloadChecksum getResponseConfigMd5() {
+        Inspector md5Field = getResponseField(RESPONSE_CONFIG_MD5);
+        return md5Field.valid()
+                ? new PayloadChecksum(md5Field.asString(), MD5)
+                : PayloadChecksum.empty(MD5);
+    }
+
+    PayloadChecksum getResponseConfigXxhash64() {
+        Inspector xxhash64Field = getResponseField(RESPONSE_CONFIG_XXHASH64);
+        return xxhash64Field.valid()
+                ? new PayloadChecksum(xxhash64Field.asString(), XXHASH64)
+                : PayloadChecksum.empty(XXHASH64);
+    }
+
+
+    PayloadChecksums getResponseConfigChecksums() {
+        PayloadChecksum responseConfigMd5 = getResponseConfigMd5();
+        System.out.println(responseConfigMd5);
+        return PayloadChecksums.from(responseConfigMd5, getResponseConfigXxhash64());
     }
 
     CompressionInfo getCompressionInfo() {
diff --git a/config/src/main/java/com/yahoo/vespa/config/util/ConfigUtils.java b/config/src/main/java/com/yahoo/vespa/config/util/ConfigUtils.java
index a7fc8afcad9..329661bf7ae 100644
--- a/config/src/main/java/com/yahoo/vespa/config/util/ConfigUtils.java
+++ b/config/src/main/java/com/yahoo/vespa/config/util/ConfigUtils.java
@@ -10,6 +10,8 @@ import com.yahoo.text.AbstractUtf8Array;
 import com.yahoo.text.Utf8;
 import com.yahoo.vespa.config.ConfigDefinitionKey;
 import com.yahoo.vespa.config.ConfigPayload;
+import net.jpountz.xxhash.XXHash64;
+import net.jpountz.xxhash.XXHashFactory;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -94,6 +96,15 @@ public class ConfigUtils {
         }
     }
 
+    public static String getXxhash64(AbstractUtf8Array input) {
+        return getXxhash64(input.wrap());
+    }
+
+    public static String getXxhash64(ByteBuffer input) {
+        XXHash64 hasher = XXHashFactory.fastestInstance().hash64();
+        return Long.toHexString(hasher.hash(input, 0)).toLowerCase();
+    }
+
     /**
      * Replaces sequences of spaces with 1 space, unless inside quotes. Public for testing;
      *
diff --git a/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java b/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java
index 7bdaeb7d367..919155a3944 100644
--- a/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java
+++ b/config/src/test/java/com/yahoo/config/subscription/impl/JRTConfigRequesterTest.java
@@ -9,6 +9,7 @@ import com.yahoo.vespa.config.ConfigKey;
 import com.yahoo.vespa.config.ConnectionPool;
 import com.yahoo.vespa.config.ErrorCode;
 import com.yahoo.vespa.config.ErrorType;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.vespa.config.TimingValues;
 import com.yahoo.vespa.config.protocol.JRTServerConfigRequestV3;
 import org.junit.Test;
@@ -139,7 +140,7 @@ public class JRTConfigRequesterTest {
         ConfigSubscriber subscriber = new ConfigSubscriber();
         final TimingValues timingValues = getTestTimingValues();
         JRTConfigSubscription<SimpletypesConfig> sub = createSubscription(subscriber, timingValues);
-        sub.setConfig(1L, false, config(), PayloadChecksum.empty());
+        sub.setConfig(1L, false, config(), PayloadChecksums.empty());
 
         final MockConnection connection = new MockConnection(new ErrorResponseHandler());
         JRTConfigRequester requester = new JRTConfigRequester(connection, timingValues);
@@ -165,7 +166,7 @@ public class JRTConfigRequesterTest {
         ConfigSubscriber subscriber = new ConfigSubscriber();
         final TimingValues timingValues = getTestTimingValues();
         JRTConfigSubscription<SimpletypesConfig> sub = createSubscription(subscriber, timingValues);
-        sub.setConfig(1L, false, config(), PayloadChecksum.empty());
+        sub.setConfig(1L, false, config(), PayloadChecksums.empty());
 
         final MockConnection connection = new MockConnection(new ErrorResponseHandler(com.yahoo.jrt.ErrorCode.TIMEOUT));
         JRTConfigRequester requester = new JRTConfigRequester(connection, timingValues);
@@ -179,7 +180,7 @@ public class JRTConfigRequesterTest {
         ConfigSubscriber subscriber = new ConfigSubscriber();
         final TimingValues timingValues = getTestTimingValues();
         JRTConfigSubscription<SimpletypesConfig> sub = createSubscription(subscriber, timingValues);
-        sub.setConfig(1L, false, config(), PayloadChecksum.empty());
+        sub.setConfig(1L, false, config(), PayloadChecksums.empty());
 
         final MockConnection connection = new MockConnection(new ErrorResponseHandler(ErrorCode.UNKNOWN_DEFINITION));
         JRTConfigRequester requester = new JRTConfigRequester(connection, timingValues);
diff --git a/config/src/test/java/com/yahoo/vespa/config/RawConfigTest.java b/config/src/test/java/com/yahoo/vespa/config/RawConfigTest.java
index e1d11f82eea..96a2d976f51 100644
--- a/config/src/test/java/com/yahoo/vespa/config/RawConfigTest.java
+++ b/config/src/test/java/com/yahoo/vespa/config/RawConfigTest.java
@@ -1,8 +1,9 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config;
 
 import com.yahoo.text.Utf8String;
-import com.yahoo.vespa.config.protocol.*;
+import com.yahoo.vespa.config.protocol.CompressionInfo;
+import com.yahoo.vespa.config.protocol.Payload;
 import com.yahoo.vespa.config.protocol.VespaVersion;
 import com.yahoo.vespa.config.util.ConfigUtils;
 import org.junit.Test;
@@ -11,6 +12,8 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.not;
 import static org.junit.Assert.assertEquals;
@@ -26,11 +29,11 @@ import static org.junit.Assert.assertThat;
 public class RawConfigTest {
 
     private static final ConfigKey<?> key = new ConfigKey<>("foo", "id", "bar");
-    private static List<String> defContent = Arrays.asList("version=1", "anInt int");
+    private static final List<String> defContent = Arrays.asList("version=1", "anInt int");
     private static final String defMd5 = ConfigUtils.getDefMd5FromRequest("", defContent);
-    private static final String configMd5 = "012345";
-    private static Payload payload = Payload.from(new Utf8String("anInt 1"), CompressionInfo.uncompressed());
-    private static long generation = 1L;
+    private static final PayloadChecksums payloadChecksums = PayloadChecksums.from("012345", "");
+    private static final Payload payload = Payload.from(new Utf8String("anInt 1"), CompressionInfo.uncompressed());
+    private static final long generation = 1L;
 
     @Test
     public void basic() {
@@ -47,7 +50,7 @@ public class RawConfigTest {
         RawConfig copiedConfig = new RawConfig(config);
         assertEquals(config, copiedConfig);
 
-        assertEquals("bar.foo," + defMd5 + ",id,,0,null", config.toString());
+        assertEquals("bar.foo," + defMd5 + ",id,MD5:,XXHASH64:,0,null", config.toString());
         assertEquals(Optional.empty(), config.getVespaVersion());
     }
 
@@ -61,14 +64,14 @@ public class RawConfigTest {
         assertThat(config.hashCode(), is(not(new RawConfig(key, "a").hashCode()))); // different def md5
 
         // different generation
-        config = new RawConfig(key, defMd5, payload, configMd5, generation, false, defContent, Optional.empty());
-        RawConfig config2 = new RawConfig(key, defMd5, payload, configMd5, 2L, false, defContent, Optional.empty());
+        config = new RawConfig(key, defMd5, payload, payloadChecksums, generation, false, defContent, Optional.empty());
+        RawConfig config2 = new RawConfig(key, defMd5, payload, payloadChecksums, 2L, false, defContent, Optional.empty());
         assertThat(config, is(not(config2)));
         assertThat(config.hashCode(), is(not(config2.hashCode())));
 
         // different config md5 and with vespa version
         final VespaVersion vespaVersion = VespaVersion.fromString("5.37.38");
-        RawConfig config3 = new RawConfig(key, defMd5, payload, "9999", generation, false, defContent, Optional.of(vespaVersion));
+        RawConfig config3 = new RawConfig(key, defMd5, payload, PayloadChecksums.from("9999", ""), generation, false, defContent, Optional.of(vespaVersion));
         assertThat(config, is(not(config3)));
         assertThat(config.hashCode(), is(not(config3.hashCode())));
         // Check that vespa version is set correctly
@@ -82,42 +85,43 @@ public class RawConfigTest {
         assertNotEquals(config, key);
 
         // errors
-        RawConfig errorConfig1 = new RawConfig(key, defMd5, payload, configMd5, generation, false, 1, defContent, Optional.empty());
+        RawConfig errorConfig1 = new RawConfig(key, defMd5, payload, payloadChecksums, generation, false, 1, defContent, Optional.empty());
         assertThat(errorConfig1, is(errorConfig1));
         assertThat(config, is(not(errorConfig1)));
         assertThat(config.hashCode(), is(not(errorConfig1.hashCode())));
         assertThat(errorConfig1, is(errorConfig1));
-        RawConfig errorConfig2 = new RawConfig(key, defMd5, payload, configMd5, generation, false, 2, defContent, Optional.empty());
+        RawConfig errorConfig2 = new RawConfig(key, defMd5, payload, payloadChecksums, generation, false, 2, defContent, Optional.empty());
         assertThat(errorConfig1, is(not(errorConfig2)));
         assertThat(errorConfig1.hashCode(), is(not(errorConfig2.hashCode())));
     }
 
     @Test
     public void payload() {
-        RawConfig config = new RawConfig(key, defMd5, payload, configMd5, generation, false, defContent, Optional.empty());
-        assertThat(config.getPayload(), is(payload));
-        assertThat(config.getConfigMd5(), is(configMd5));
-        assertThat(config.getGeneration(), is(generation));
-        assertThat(config.getDefContent(), is(defContent));
+        RawConfig config = new RawConfig(key, defMd5, payload, payloadChecksums, generation, false, defContent, Optional.empty());
+        assertEquals(config.getPayload(), payload);
+        assertEquals(config.getConfigMd5(), payloadChecksums.getForType(MD5).asString());
+        assertEquals(config.getPayloadChecksums().getForType(XXHASH64), payloadChecksums.getForType(XXHASH64));
+        assertEquals(config.getGeneration(), generation);
+        assertEquals(config.getDefContent(), defContent);
     }
 
     @Test
     public void require_correct_defmd5() {
         final String defMd5ForEmptyDefContent = "d41d8cd98f00b204e9800998ecf8427e";
 
-        RawConfig config = new RawConfig(key, null, payload, configMd5, generation, false, defContent, Optional.empty());
+        RawConfig config = new RawConfig(key, null, payload, payloadChecksums, generation, false, defContent, Optional.empty());
         assertThat(config.getDefMd5(), is(defMd5));
-        config = new RawConfig(key, "", payload, configMd5, generation, false, defContent, Optional.empty());
+        config = new RawConfig(key, "", payload, payloadChecksums, generation, false, defContent, Optional.empty());
         assertThat(config.getDefMd5(), is(defMd5));
-        config = new RawConfig(key, defMd5, payload, configMd5, generation, false, defContent, Optional.empty());
+        config = new RawConfig(key, defMd5, payload, payloadChecksums, generation, false, defContent, Optional.empty());
         assertThat(config.getDefMd5(), is(defMd5));
-        config = new RawConfig(key, null, payload, configMd5, generation, false, null, Optional.empty());
+        config = new RawConfig(key, null, payload, payloadChecksums, generation, false, null, Optional.empty());
         assertNull(config.getDefMd5());
-        config = new RawConfig(key, null, payload, configMd5, generation, false, List.of(""), Optional.empty());
+        config = new RawConfig(key, null, payload, payloadChecksums, generation, false, List.of(""), Optional.empty());
         assertThat(config.getDefMd5(), is(defMd5ForEmptyDefContent));
-        config = new RawConfig(key, "", payload, configMd5, generation, false, null, Optional.empty());
+        config = new RawConfig(key, "", payload, payloadChecksums, generation, false, null, Optional.empty());
         assertThat(config.getDefMd5(), is(""));
-        config = new RawConfig(key, "", payload, configMd5, generation, false, List.of(""), Optional.empty());
+        config = new RawConfig(key, "", payload, payloadChecksums, generation, false, List.of(""), Optional.empty());
         assertThat(config.getDefMd5(), is(defMd5ForEmptyDefContent));
     }
 
diff --git a/config/src/test/java/com/yahoo/vespa/config/RequestValidationTest.java b/config/src/test/java/com/yahoo/vespa/config/RequestValidationTest.java
index 8c11db15f7c..2b7fd9c350b 100644
--- a/config/src/test/java/com/yahoo/vespa/config/RequestValidationTest.java
+++ b/config/src/test/java/com/yahoo/vespa/config/RequestValidationTest.java
@@ -1,10 +1,11 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config;
 
-import com.yahoo.config.subscription.impl.PayloadChecksum;
 import com.yahoo.vespa.config.protocol.RequestValidation;
 import org.junit.Test;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
@@ -21,11 +22,12 @@ public class RequestValidationTest {
 
     @Test
     public void testVerifyDefMd5() {
-        assertTrue(PayloadChecksum.empty().valid());
-        assertTrue(new PayloadChecksum("e8f0c01c7c3dcb8d3f62d7ff777fce6b").valid());
-        assertTrue(new PayloadChecksum("e8f0c01c7c3dcb8d3f62d7ff777fce6B").valid());
-        assertFalse(new PayloadChecksum("aaaaaaaaaaaaaaaaaa").valid());
-        assertFalse(new PayloadChecksum("-8f0c01c7c3dcb8d3f62d7ff777fce6b").valid());
+        assertTrue(PayloadChecksum.empty(MD5).valid());
+        assertTrue(new PayloadChecksum("e8f0c01c7c3dcb8d3f62d7ff777fce6b", MD5).valid());
+        assertTrue(new PayloadChecksum("e8f0c01c7c3dcb8d3f62d7ff777fce6B", MD5).valid());
+        assertTrue(new PayloadChecksum("e8f0c01c7c3dcb8d", XXHASH64).valid());
+        assertFalse(new PayloadChecksum("aaaaaaaaaaaaaaaaaa", MD5).valid());
+        assertFalse(new PayloadChecksum("-8f0c01c7c3dcb8d3f62d7ff777fce6b", MD5).valid());
     }
 
     @Test
diff --git a/config/src/test/java/com/yahoo/vespa/config/protocol/ConfigResponseTest.java b/config/src/test/java/com/yahoo/vespa/config/protocol/ConfigResponseTest.java
index c53a6b5c73d..f00e95ccea2 100644
--- a/config/src/test/java/com/yahoo/vespa/config/protocol/ConfigResponseTest.java
+++ b/config/src/test/java/com/yahoo/vespa/config/protocol/ConfigResponseTest.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.
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.protocol;
 
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.foo.SimpletypesConfig;
 import com.yahoo.text.AbstractUtf8Array;
 import com.yahoo.text.Utf8Array;
@@ -12,6 +13,8 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
@@ -23,14 +26,20 @@ public class ConfigResponseTest {
     @Test
     public void require_that_slime_response_is_initialized() throws IOException {
         ConfigPayload configPayload = ConfigPayload.fromInstance(new SimpletypesConfig(new SimpletypesConfig.Builder()));
-        ConfigResponse response = SlimeConfigResponse.fromConfigPayload(configPayload, 3, false, "mymd5");
+        PayloadChecksums payloadChecksums = PayloadChecksums.fromPayload(Payload.from(configPayload));
+        ConfigResponse response =
+                SlimeConfigResponse.fromConfigPayload(configPayload,
+                                                      3,
+                                                      false,
+                                                      payloadChecksums);
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         response.serialize(baos, CompressionType.UNCOMPRESSED);
         String payload = baos.toString(StandardCharsets.UTF_8);
         assertNotNull(payload);
-        assertEquals("{\"boolval\":false,\"doubleval\":0.0,\"enumval\":\"VAL1\",\"intval\":0,\"longval\":0,\"stringval\":\"s\"}", payload.toString());
-        assertEquals(response.getGeneration(), 3L);
-        assertEquals(response.getConfigMd5(), "mymd5");
+        assertEquals("{\"boolval\":false,\"doubleval\":0.0,\"enumval\":\"VAL1\",\"intval\":0,\"longval\":0,\"stringval\":\"s\"}", payload);
+        assertEquals(3L, response.getGeneration());
+        assertEquals(payloadChecksums.getForType(MD5), response.getPayloadChecksums().getForType(MD5));
+        assertEquals(payloadChecksums.getForType(XXHASH64), response.getPayloadChecksums().getForType(XXHASH64));
 
         baos = new ByteArrayOutputStream();
         response.serialize(baos, CompressionType.UNCOMPRESSED);
@@ -42,7 +51,7 @@ public class ConfigResponseTest {
         ConfigPayload configPayload = ConfigPayload.fromInstance(new SimpletypesConfig(new SimpletypesConfig.Builder()));
         AbstractUtf8Array data = configPayload.toUtf8Array(true);
         Utf8Array bytes = new Utf8Array(new LZ4PayloadCompressor().compress(data.wrap()));
-        ConfigResponse response = new SlimeConfigResponse(bytes, 3, false, "mymd5", CompressionInfo.create(CompressionType.LZ4, data.getByteLength()));
+        ConfigResponse response = new SlimeConfigResponse(bytes, 3, false, PayloadChecksums.empty(), CompressionInfo.create(CompressionType.LZ4, data.getByteLength()));
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         response.serialize(baos, CompressionType.UNCOMPRESSED);
         String payload = baos.toString(StandardCharsets.UTF_8);
diff --git a/config/src/test/java/com/yahoo/vespa/config/protocol/JRTConfigRequestV3Test.java b/config/src/test/java/com/yahoo/vespa/config/protocol/JRTConfigRequestV3Test.java
index d6ce246aa1f..5a3110c9221 100644
--- a/config/src/test/java/com/yahoo/vespa/config/protocol/JRTConfigRequestV3Test.java
+++ b/config/src/test/java/com/yahoo/vespa/config/protocol/JRTConfigRequestV3Test.java
@@ -8,6 +8,7 @@ import com.yahoo.config.subscription.impl.GenericConfigSubscriber;
 import com.yahoo.config.subscription.impl.JRTConfigRequester;
 import com.yahoo.config.subscription.impl.JRTConfigSubscription;
 import com.yahoo.config.subscription.impl.MockConnection;
+import com.yahoo.vespa.config.PayloadChecksums;
 import com.yahoo.foo.SimpletypesConfig;
 import com.yahoo.jrt.Request;
 import com.yahoo.slime.Inspector;
@@ -27,6 +28,8 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 
+import static com.yahoo.vespa.config.PayloadChecksum.Type.MD5;
+import static com.yahoo.vespa.config.PayloadChecksum.Type.XXHASH64;
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -53,7 +56,7 @@ public class JRTConfigRequestV3Test {
     private final long currentGeneration = 3;
     private final long timeout = 5000;
     private Trace trace ;
-    private final String configMd5 = ConfigUtils.getMd5(createPayload().getData());
+    private final PayloadChecksums payloadChecksums = PayloadChecksums.fromPayload(createPayload());
     private JRTClientConfigRequest clientReq;
     private JRTServerConfigRequest serverReq;
 
@@ -79,8 +82,12 @@ public class JRTConfigRequestV3Test {
     @Test
     public void emptypayload() {
         ConfigPayload payload = ConfigPayload.empty();
-        SlimeConfigResponse response = SlimeConfigResponse.fromConfigPayload(payload, 0, false, ConfigUtils.getMd5(payload));
-        serverReq.addOkResponse(serverReq.payloadFromResponse(response), response.getGeneration(),  false, response.getConfigMd5());
+        PayloadChecksums payloadChecksums = PayloadChecksums.fromPayload(Payload.from(payload));
+        SlimeConfigResponse response = SlimeConfigResponse.fromConfigPayload(payload,
+                                                                             0,
+                                                                             false,
+                                                                             payloadChecksums);
+        serverReq.addOkResponse(serverReq.payloadFromResponse(response), response.getGeneration(),  false, payloadChecksums);
         assertTrue(clientReq.validateResponse());
         assertTrue(clientReq.hasUpdatedGeneration());
         assertEquals("{}", clientReq.getNewPayload().withCompression(CompressionType.UNCOMPRESSED).getData().toString());
@@ -97,7 +104,8 @@ public class JRTConfigRequestV3Test {
 
     @Test
     public void next_request_when_error_is_correct() {
-        serverReq.addOkResponse(createPayload(), 999999, false, "newmd5");
+        Payload payload = createPayload();
+        serverReq.addOkResponse(payload, 999999, false, PayloadChecksums.fromPayload(payload));
         serverReq.addErrorResponse(ErrorCode.OUTDATED_CONFIG, "error message");
         JRTClientConfigRequest next = clientReq.nextRequest(6);
         // Should use config md5 and generation from the request, not the response
@@ -111,7 +119,7 @@ public class JRTConfigRequestV3Test {
         Payload payload = createPayload("vale");
         String md5 = ConfigUtils.getMd5(payload.getData());
         long generation = 4L;
-        serverReq.addOkResponse(payload, generation, false, md5);
+        serverReq.addOkResponse(payload, generation, false, PayloadChecksums.fromPayload(payload));
         assertTrue(clientReq.validateResponse());
         assertThat(clientReq.getNewPayload().withCompression(CompressionType.UNCOMPRESSED).getData().toString(), is(payload.getData().toString()));
         assertThat(clientReq.getNewGeneration(), is(4L));
@@ -137,7 +145,7 @@ public class JRTConfigRequestV3Test {
     @Test
     public void generation_only_is_updated() {
         Payload payload = createPayload();
-        serverReq.addOkResponse(payload, 4L, false, ConfigUtils.getMd5(payload.getData()));
+        serverReq.addOkResponse(payload, 4L, false, PayloadChecksums.fromPayload(payload));
         boolean value = clientReq.validateResponse();
         assertTrue(clientReq.errorMessage(), value);
         assertFalse(clientReq.hasUpdatedConfig());
@@ -147,7 +155,7 @@ public class JRTConfigRequestV3Test {
     @Test
     public void nothing_is_updated() {
         Payload payload = createPayload();
-        serverReq.addOkResponse(payload, currentGeneration, false, configMd5);
+        serverReq.addOkResponse(payload, currentGeneration, false, payloadChecksums);
         assertTrue(clientReq.validateResponse());
         assertFalse(clientReq.hasUpdatedConfig());
         assertFalse(clientReq.hasUpdatedGeneration());
@@ -158,7 +166,7 @@ public class JRTConfigRequestV3Test {
         Payload payload = Payload.from(ConfigPayload.empty());
         clientReq = createReq(payload);
         serverReq = createReq(clientReq.getRequest());
-        serverReq.addOkResponse(payload, currentGeneration, false, ConfigUtils.getMd5(payload.getData()));
+        serverReq.addOkResponse(payload, currentGeneration, false, PayloadChecksums.fromPayload(payload));
         boolean val = clientReq.validateResponse();
         assertTrue(clientReq.errorMessage(), val);
         assertFalse(clientReq.hasUpdatedConfig());
@@ -195,7 +203,7 @@ public class JRTConfigRequestV3Test {
             @Override
             public void createResponse() {
                 JRTServerConfigRequest serverRequest = createReq(request);
-                serverRequest.addOkResponse(createPayload(), currentGeneration, false, configMd5);
+                serverRequest.addOkResponse(createPayload(), currentGeneration, false, payloadChecksums);
             }
         });
 
@@ -206,8 +214,10 @@ public class JRTConfigRequestV3Test {
         assertTrue(sub.nextConfig(120_0000));
         sub.close();
         JRTClientConfigRequest nextReq = createReq(sub, Trace.createNew());
-        assertThat(nextReq.getRequestConfigMd5(), is(sub.getConfigState().getChecksum().asString()));
-        assertThat(nextReq.getRequestGeneration(), is(currentGeneration));
+        assertEquals(nextReq.getRequestConfigMd5(), sub.getConfigState().getChecksums().getForType(MD5).asString());
+        assertEquals(nextReq.getRequestConfigChecksums().getForType(MD5).asString(), sub.getConfigState().getChecksums().getForType(MD5).asString());
+        assertEquals(nextReq.getRequestConfigChecksums().getForType(XXHASH64).asString(), sub.getConfigState().getChecksums().getForType(XXHASH64).asString());
+        assertEquals(nextReq.getRequestGeneration(), currentGeneration);
     }
 
     @Test
@@ -225,12 +235,12 @@ public class JRTConfigRequestV3Test {
     @Test
     public void parameters_are_validated() {
         assertTrue(serverReq.validateParameters());
-        assertValidationFail(createReq("35#$#!$@#", defNamespace, hostname, configId, configMd5, currentGeneration, timeout, trace));
-        assertValidationFail(createReq(defName, "abcd.o#$*(!&$", hostname, configId, configMd5, currentGeneration, timeout, trace));
-        assertValidationFail(createReq(defName, defNamespace, hostname, configId, "34", currentGeneration, timeout, trace));
-        assertValidationFail(createReq(defName, defNamespace, hostname, configId, configMd5, -34, timeout, trace));
-        assertValidationFail(createReq(defName, defNamespace, hostname, configId, configMd5, currentGeneration, -23, trace));
-        assertValidationFail(createReq(defName, defNamespace, "", configId, configMd5, currentGeneration, timeout, trace));
+        assertValidationFail(createReq("35#$#!$@#", defNamespace, hostname, configId, payloadChecksums, currentGeneration, timeout, trace));
+        assertValidationFail(createReq(defName, "abcd.o#$*(!&$", hostname, configId, payloadChecksums, currentGeneration, timeout, trace));
+        assertValidationFail(createReq(defName, defNamespace, hostname, configId, PayloadChecksums.from("abcd", "1234"), currentGeneration, timeout, trace));
+        assertValidationFail(createReq(defName, defNamespace, hostname, configId, payloadChecksums, -34, timeout, trace));
+        assertValidationFail(createReq(defName, defNamespace, hostname, configId, payloadChecksums, currentGeneration, -23, trace));
+        assertValidationFail(createReq(defName, defNamespace, "", configId, payloadChecksums, currentGeneration, timeout, trace));
     }
 
     private void assertValidationFail(JRTClientConfigRequest req) {
@@ -248,12 +258,12 @@ public class JRTConfigRequestV3Test {
     }
 
     private JRTClientConfigRequest createReq(String defName, String defNamespace,
-                                             String hostname, String configId, String configMd5,
+                                             String hostname, String configId, PayloadChecksums payloadChecksums,
                                              long currentGeneration, long timeout, Trace trace) {
         return JRTClientConfigRequestV3.createWithParams(ConfigKey.createFull(defName, configId, defNamespace),
                                                          DefContent.fromList(List.of(configDefinition)),
                                                          hostname,
-                                                         configMd5,
+                                                         payloadChecksums,
                                                          currentGeneration,
                                                          timeout,
                                                          trace,
@@ -276,13 +286,13 @@ public class JRTConfigRequestV3Test {
     private JRTClientConfigRequest createReq() {
         trace = Trace.createNew(3, new ManualClock());
         trace.trace(1, "hei");
-        return createReq(defName, defNamespace, hostname, configId, configMd5, currentGeneration, timeout, trace);
+        return createReq(defName, defNamespace, hostname, configId, payloadChecksums, currentGeneration, timeout, trace);
     }
 
     private JRTClientConfigRequest createReq(Payload payload) {
         trace = Trace.createNew(3, new ManualClock());
         trace.trace(1, "hei");
-        return createReq(defName, defNamespace, hostname, configId, ConfigUtils.getMd5(payload.getData()), currentGeneration, timeout, trace);
+        return createReq(defName, defNamespace, hostname, configId, PayloadChecksums.fromPayload(payload), currentGeneration, timeout, trace);
     }
 
     private void request_is_parsed_base() {
@@ -294,7 +304,8 @@ public class JRTConfigRequestV3Test {
         assertThat(serverReq.getDefContent().asStringArray(), is(configDefinition));
         assertFalse(serverReq.noCache());
         assertTrue(serverReq.getRequestTrace().toString().contains("hi"));
-        assertThat(serverReq.getRequestConfigMd5(), is(configMd5));
+        assertThat(serverReq.getRequestConfigChecksums().getForType(MD5), is(payloadChecksums.getForType(MD5)));
+        assertThat(serverReq.getRequestConfigChecksums().getForType(XXHASH64), is(payloadChecksums.getForType(XXHASH64)));
         assertThat(serverReq.getRequestGeneration(), is(currentGeneration));
     }