NIFI-826 This closes #617. Added deterministic template support

nifi-commons/nifi-utils/src/main/java/org/apache/nifi/util/TypeOneUUIDGenerator.java

@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.util;
+
+import java.util.Random;
+import java.util.UUID;
+
+public class TypeOneUUIDGenerator {
+
+    public static final Object lock = new Object();
+
+    private static long lastTime;
+    private static long clockSequence = 0;
+    private static final Random randomGenerator = new Random();
+
+    /**
+     * Will generate unique time based UUID where the next UUID is always
+     * greater then the previous.
+     */
+    public final static UUID generateId() {
+        return generateId(System.currentTimeMillis());
+    }
+
+    /**
+     *
+     */
+    public final static UUID generateId(long currentTime) {
+        return generateId(currentTime, Math.abs(randomGenerator.nextInt()));
+    }
+
+    /**
+     *
+     */
+    public final static UUID generateId(long currentTime, int lsbInt) {
+        long time;
+
+        synchronized (lock) {
+            if (currentTime > lastTime) {
+                lastTime = currentTime;
+                clockSequence = 0;
+            } else {
+                ++clockSequence;
+            }
+        }
+
+        time = currentTime;
+
+        // low Time
+        time = currentTime << 32;
+
+        // mid Time
+        time |= ((currentTime & 0xFFFF00000000L) >> 16);
+
+        // hi Time
+        time |= 0x1000 | ((currentTime >> 48) & 0x0FFF);
+
+        long clockSequenceHi = clockSequence;
+        clockSequenceHi <<= 48;
+        long lsb = clockSequenceHi | lsbInt;
+        return new UUID(time, lsb);
+    }
+}

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-client-dto/src/main/java/org/apache/nifi/web/api/dto/FlowSnippetDTO.java

@@ -16,11 +16,16 @@
  */
 package org.apache.nifi.web.api.dto;
 
-import com.wordnik.swagger.annotations.ApiModelProperty;
+import java.util.Comparator;
 import java.util.LinkedHashSet;
 import java.util.Set;
+import java.util.TreeSet;
+import java.util.UUID;
+
 import javax.xml.bind.annotation.XmlType;
 
+import com.wordnik.swagger.annotations.ApiModelProperty;
+
 /**
  * The contents of a flow snippet.
  */
@@ -37,6 +42,15 @@ public class FlowSnippetDTO {
     private Set<FunnelDTO> funnels = new LinkedHashSet<>();
     private Set<ControllerServiceDTO> controllerServices = new LinkedHashSet<>();
 
+    private final boolean newTemplate;
+
+    public FlowSnippetDTO() {
+        this(false);
+    }
+
+    public FlowSnippetDTO(boolean newTemplate) {
+        this.newTemplate = newTemplate;
+    }
     /**
      * @return connections in this flow snippet
      */
@@ -48,7 +62,8 @@ public class FlowSnippetDTO {
     }
 
     public void setConnections(Set<ConnectionDTO> connections) {
-        this.connections = connections;
+        this.removeInstanceIdentifierIfNecessary(connections);
+        this.connections = this.orderedById(connections);
     }
 
     /**
@@ -62,7 +77,8 @@ public class FlowSnippetDTO {
     }
 
     public void setInputPorts(Set<PortDTO> inputPorts) {
-        this.inputPorts = inputPorts;
+        this.removeInstanceIdentifierIfNecessary(inputPorts);
+        this.inputPorts = this.orderedById(inputPorts);
     }
 
     /**
@@ -76,7 +92,8 @@ public class FlowSnippetDTO {
     }
 
     public void setLabels(Set<LabelDTO> labels) {
-        this.labels = labels;
+        this.removeInstanceIdentifierIfNecessary(labels);
+        this.labels = this.orderedById(labels);
     }
 
     /**
@@ -90,7 +107,8 @@ public class FlowSnippetDTO {
     }
 
     public void setFunnels(Set<FunnelDTO> funnels) {
-        this.funnels = funnels;
+        this.removeInstanceIdentifierIfNecessary(funnels);
+        this.funnels = this.orderedById(funnels);
     }
 
     /**
@@ -104,7 +122,8 @@ public class FlowSnippetDTO {
     }
 
     public void setOutputPorts(Set<PortDTO> outputPorts) {
-        this.outputPorts = outputPorts;
+        this.removeInstanceIdentifierIfNecessary(outputPorts);
+        this.outputPorts = this.orderedById(outputPorts);
     }
 
     /**
@@ -118,7 +137,8 @@ public class FlowSnippetDTO {
     }
 
     public void setProcessGroups(Set<ProcessGroupDTO> processGroups) {
-        this.processGroups = processGroups;
+        this.removeInstanceIdentifierIfNecessary(processGroups);
+        this.processGroups = this.orderedById(processGroups);
     }
 
     /**
@@ -132,7 +152,8 @@ public class FlowSnippetDTO {
     }
 
     public void setProcessors(Set<ProcessorDTO> processors) {
-        this.processors = processors;
+        this.removeInstanceIdentifierIfNecessary(processors);
+        this.processors = this.orderedById(processors);
     }
 
     /**
@@ -146,7 +167,8 @@ public class FlowSnippetDTO {
     }
 
     public void setRemoteProcessGroups(Set<RemoteProcessGroupDTO> remoteProcessGroups) {
-        this.remoteProcessGroups = remoteProcessGroups;
+        this.removeInstanceIdentifierIfNecessary(remoteProcessGroups);
+        this.remoteProcessGroups = this.orderedById(remoteProcessGroups);
     }
 
     /**
@@ -160,6 +182,40 @@ public class FlowSnippetDTO {
     }
 
     public void setControllerServices(Set<ControllerServiceDTO> controllerServices) {
-        this.controllerServices = controllerServices;
+        this.removeInstanceIdentifierIfNecessary(controllerServices);
+        this.controllerServices = this.orderedById(controllerServices);
+    }
+
+    private <T extends ComponentDTO> Set<T> orderedById(Set<T> dtos) {
+        TreeSet<T> components = new TreeSet<>(new Comparator<ComponentDTO>() {
+            @Override
+            public int compare(ComponentDTO c1, ComponentDTO c2) {
+                return UUID.fromString(c1.getId()).compareTo(UUID.fromString(c2.getId()));
+            }
+        });
+        components.addAll(dtos);
+        return components;
+    }
+
+    private void removeInstanceIdentifierIfNecessary(Set<? extends ComponentDTO> componentDtos) {
+        if (this.newTemplate) {
+            for (ComponentDTO componentDto : componentDtos) {
+                UUID id = UUID.fromString(componentDto.getId());
+                id = new UUID(id.getMostSignificantBits(), 0);
+                componentDto.setId(id.toString());
+                if (componentDto instanceof ConnectionDTO) {
+                    ConnectionDTO connectionDTO = (ConnectionDTO) componentDto;
+                    ConnectableDTO cdto = connectionDTO.getSource();
+                    id = UUID.fromString(cdto.getId());
+                    id = new UUID(id.getMostSignificantBits(), 0);
+                    cdto.setId(id.toString());
+
+                    cdto = connectionDTO.getDestination();
+                    id = UUID.fromString(cdto.getId());
+                    id = new UUID(id.getMostSignificantBits(), 0);
+                    cdto.setId(id.toString());
+                }
+            }
+        }
     }
 }

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-cluster/src/main/java/org/apache/nifi/cluster/coordination/http/replication/ThreadPoolRequestReplicator.java

@@ -41,6 +41,7 @@ import org.apache.nifi.cluster.protocol.NodeIdentifier;
 import org.apache.nifi.events.EventReporter;
 import org.apache.nifi.reporting.Severity;
 import org.apache.nifi.util.FormatUtils;
+import org.apache.nifi.util.TypeOneUUIDGenerator;
 import org.apache.nifi.web.security.ProxiedEntitiesUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -216,12 +217,13 @@ public class ThreadPoolRequestReplicator implements RequestReplicator {
     @Override
     public AsyncClusterResponse replicate(Set<NodeIdentifier> nodeIds, String method, URI uri, Object entity, Map<String, String> headers, final boolean indicateReplicated) {
         final Map<String, String> updatedHeaders = new HashMap<>(headers);
-        updatedHeaders.put(RequestReplicator.CLUSTER_ID_GENERATION_SEED_HEADER, UUID.randomUUID().toString());
 
+        updatedHeaders.put(RequestReplicator.CLUSTER_ID_GENERATION_SEED_HEADER, TypeOneUUIDGenerator.generateId().toString());
         if (indicateReplicated) {
             updatedHeaders.put(RequestReplicator.REPLICATION_INDICATOR_HEADER, "true");
         }
 
+
         // If the user is authenticated, add them as a proxied entity so that when the receiving NiFi receives the request,
         // it knows that we are acting as a proxy on behalf of the current user.
         final NiFiUser user = NiFiUserUtils.getNiFiUser();

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/pom.xml

@@ -174,6 +174,12 @@
             <artifactId>cglib-nodep</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.eclipse.jgit</groupId>
+            <artifactId>org.eclipse.jgit</artifactId>
+            <version>4.3.1.201605051710-r</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/persistence/TemplateSerializer.java

@@ -26,6 +26,11 @@ import javax.xml.bind.Marshaller;
 import java.io.BufferedOutputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import javax.xml.stream.XMLOutputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamWriter;
+
+import com.sun.xml.txw2.output.IndentingXMLStreamWriter;
 
 public final class TemplateSerializer {
 
@@ -39,12 +44,13 @@ public final class TemplateSerializer {
 
             JAXBContext context = JAXBContext.newInstance(TemplateDTO.class);
             Marshaller marshaller = context.createMarshaller();
-            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
+            XMLOutputFactory xmlof = XMLOutputFactory.newInstance();
-            marshaller.marshal(dto, bos);
+            XMLStreamWriter writer = new IndentingXMLStreamWriter(xmlof.createXMLStreamWriter(bos));
+            marshaller.marshal(dto, writer);
 
             bos.flush();
             return baos.toByteArray();
-        } catch (final IOException | JAXBException e) {
+        } catch (final IOException | JAXBException | XMLStreamException e) {
             throw new FlowSerializationException(e);
         } finally {
             if (currentCl != null) {

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/test/groovy/org/apache/nifi/util/SnippetUtilsSpec.groovy

@@ -43,7 +43,7 @@ class SnippetUtilsSpec extends Specification {
         where:
         nX  | nY  | oX | oY | fX  | fY   | snippet
         500 | 500 | 0  | 0  | 1.5 | 1.34 | new FlowSnippetDTO()
-        500 | 500 | 10 | 10 | 1.5 | 1.34 | new FlowSnippetDTO(processors: [new ProcessorDTO(position: new PositionDTO(x: 10, y: 10))])
+        500 | 500 | 10 | 10 | 1.5 | 1.34 | new FlowSnippetDTO(processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0000-c4af042cb1559", position: new PositionDTO(x: 10, y: 10))])
     }
 
     @Unroll
@@ -69,10 +69,10 @@ class SnippetUtilsSpec extends Specification {
         fX  | fY   | snippet
         1.5 | 1.34 | new FlowSnippetDTO()
         1.5 | 1.34 | new FlowSnippetDTO(
-                processors: [new ProcessorDTO(position: new PositionDTO(x: 10, y: 10))],
+                processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0001-c4af042cb1559", position: new PositionDTO(x: 10, y: 10))],
                 processGroups: [
-                        new ProcessGroupDTO(position: new PositionDTO(x: 105, y: -10), name: 'pg2',
+                        new ProcessGroupDTO(id:"c81f6a10-0155-1000-0002-c4af042cb1559", position: new PositionDTO(x: 105, y: -10), name: 'pg2',
-                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(name: 'proc1', position: new PositionDTO(x: 50, y: 60))]))])
+                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0002-c4af042cb1559", name: 'proc1', position: new PositionDTO(x: 50, y: 60))]))])
 
     }
 

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/test/java/org/apache/nifi/persistence/TemplateSerializerTest.java

@@ -0,0 +1,140 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.persistence;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.InputStreamReader;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.nio.charset.StandardCharsets;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Collectors;
+
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.JAXBElement;
+import javax.xml.bind.Unmarshaller;
+import javax.xml.transform.stream.StreamSource;
+
+import org.apache.nifi.nar.NarClassLoader;
+import org.apache.nifi.nar.NarClassLoaders;
+import org.apache.nifi.util.TypeOneUUIDGenerator;
+import org.apache.nifi.web.api.dto.FlowSnippetDTO;
+import org.apache.nifi.web.api.dto.ProcessorDTO;
+import org.apache.nifi.web.api.dto.TemplateDTO;
+import org.eclipse.jgit.diff.DiffFormatter;
+import org.eclipse.jgit.diff.EditList;
+import org.eclipse.jgit.diff.HistogramDiff;
+import org.eclipse.jgit.diff.RawText;
+import org.eclipse.jgit.diff.RawTextComparator;
+import org.junit.Before;
+import org.junit.Test;
+
+public class TemplateSerializerTest {
+    @Before
+    public void before() throws Exception {
+        Field initField = NarClassLoaders.class.getDeclaredField("initialized");
+        setFinalField(initField, new AtomicBoolean(true));
+        Field clField = NarClassLoaders.class.getDeclaredField("frameworkClassLoader");
+        NarClassLoader cl = new NarClassLoader(new File(""), Thread.currentThread().getContextClassLoader());
+        setFinalField(clField, new AtomicReference<NarClassLoader>(cl));
+    }
+
+    @Test
+    public void validateDiffWithChangingComponentIdAndAdditionalElements() throws Exception {
+
+        // Create initial template (TemplateDTO)
+        FlowSnippetDTO snippet = new FlowSnippetDTO();
+        Set<ProcessorDTO> procs = new HashSet<>();
+        for (int i = 4; i > 0; i--) {
+            ProcessorDTO procDTO = new ProcessorDTO();
+            procDTO.setType("Processor" + i + ".class");
+            procDTO.setId(TypeOneUUIDGenerator.generateId().toString());
+            procs.add(procDTO);
+        }
+        snippet.setProcessors(procs);
+        TemplateDTO origTemplate = new TemplateDTO();
+        origTemplate.setDescription("MyTemplate");
+        origTemplate.setId("MyTemplate");
+        origTemplate.setSnippet(snippet);
+        byte[] serTemplate = TemplateSerializer.serialize(origTemplate);
+
+        // Deserialize Template into TemplateDTP
+        ByteArrayInputStream in = new ByteArrayInputStream(serTemplate);
+        JAXBContext context = JAXBContext.newInstance(TemplateDTO.class);
+        Unmarshaller unmarshaller = context.createUnmarshaller();
+        JAXBElement<TemplateDTO> templateElement = unmarshaller.unmarshal(new StreamSource(in), TemplateDTO.class);
+        TemplateDTO deserTemplate = templateElement.getValue();
+
+        // Modify deserialized template
+        FlowSnippetDTO deserSnippet = deserTemplate.getSnippet();
+        Set<ProcessorDTO> deserProcs = deserSnippet.getProcessors();
+        int c = 0;
+        for (ProcessorDTO processorDTO : deserProcs) {
+            if (c % 2 == 0) {
+                processorDTO.setName("Hello-" + c);
+            }
+            c++;
+        }
+
+        // add new Processor
+        ProcessorDTO procDTO = new ProcessorDTO();
+        procDTO.setType("ProcessorNew" + ".class");
+        procDTO.setId(TypeOneUUIDGenerator.generateId().toString());
+        deserProcs.add(procDTO);
+
+        // Serialize modified template
+        byte[] serTemplate2 = TemplateSerializer.serialize(deserTemplate);
+
+        RawText rt1 = new RawText(serTemplate);
+        RawText rt2 = new RawText(serTemplate2);
+        EditList diffList = new EditList();
+        diffList.addAll(new HistogramDiff().diff(RawTextComparator.DEFAULT, rt1, rt2));
+
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        try (DiffFormatter diff = new DiffFormatter(out);) {
+            diff.format(diffList, rt1, rt2);
+
+            BufferedReader reader = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(out.toByteArray()), StandardCharsets.UTF_8));
+
+            List<String> changes = reader.lines().peek(System.out::println)
+                    .filter(line -> line.startsWith("+") || line.startsWith("-")).collect(Collectors.toList());
+
+            assertEquals("+      <name>Hello-0</name>", changes.get(0));
+            assertEquals("+      <name>Hello-2</name>", changes.get(1));
+            assertEquals("+    <processors>", changes.get(2));
+            assertEquals("+      <type>ProcessorNew.class</type>", changes.get(4));
+            assertEquals("+    </processors>", changes.get(5));
+        }
+    }
+
+    public static void setFinalField(Field field, Object newValue) throws Exception {
+        field.setAccessible(true);
+        Field modifiersField = Field.class.getDeclaredField("modifiers");
+        modifiersField.setAccessible(true);
+        modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
+        field.set(null, newValue);
+    }
+}

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-api/src/main/java/org/apache/nifi/web/api/ApplicationResource.java

@@ -41,6 +41,7 @@ import org.apache.nifi.remote.exception.NotAuthorizedException;
 import org.apache.nifi.remote.protocol.ResponseCode;
 import org.apache.nifi.remote.protocol.http.HttpHeaders;
 import org.apache.nifi.util.NiFiProperties;
+import org.apache.nifi.util.TypeOneUUIDGenerator;
 import org.apache.nifi.web.AuthorizableLookup;
 import org.apache.nifi.web.AuthorizeAccess;
 import org.apache.nifi.web.NiFiServiceFacade;
@@ -200,7 +201,19 @@ public abstract class ApplicationResource {
 
     protected String generateUuid() {
         final Optional<String> seed = getIdGenerationSeed();
-        return seed.isPresent() ? UUID.nameUUIDFromBytes(seed.get().getBytes(StandardCharsets.UTF_8)).toString() : UUID.randomUUID().toString();
+        UUID uuid;
+        if (seed.isPresent()) {
+            try {
+                UUID seedId = UUID.fromString(seed.get());
+                uuid = TypeOneUUIDGenerator.generateId(seedId.getMostSignificantBits(), Math.abs(seed.get().hashCode()));
+            } catch (Exception e) {
+                logger.warn("Provided 'seed' does not represent UUID. Will not be able to extract most significant bits for ID generation.");
+                uuid = UUID.nameUUIDFromBytes(seed.get().getBytes(StandardCharsets.UTF_8));
+            }
+        } else {
+            uuid = TypeOneUUIDGenerator.generateId();
+        }
+        return uuid.toString();
     }
 
     protected Optional<String> getIdGenerationSeed() {

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-api/src/main/java/org/apache/nifi/web/api/TemplateResource.java

@@ -16,20 +16,8 @@
  */
 package org.apache.nifi.web.api;
 
-import com.wordnik.swagger.annotations.Api;
+import java.nio.charset.StandardCharsets;
-import com.wordnik.swagger.annotations.ApiOperation;
+import java.util.Set;
-import com.wordnik.swagger.annotations.ApiParam;
-import com.wordnik.swagger.annotations.ApiResponse;
-import com.wordnik.swagger.annotations.ApiResponses;
-import com.wordnik.swagger.annotations.Authorization;
-import org.apache.commons.lang3.StringUtils;
-import org.apache.nifi.authorization.Authorizer;
-import org.apache.nifi.authorization.RequestAction;
-import org.apache.nifi.authorization.resource.Authorizable;
-import org.apache.nifi.authorization.user.NiFiUserUtils;
-import org.apache.nifi.web.NiFiServiceFacade;
-import org.apache.nifi.web.api.dto.TemplateDTO;
-import org.apache.nifi.web.api.entity.TemplateEntity;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.Consumes;
@@ -42,7 +30,23 @@ import javax.ws.rs.Produces;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
-import java.util.Set;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.nifi.authorization.Authorizer;
+import org.apache.nifi.authorization.RequestAction;
+import org.apache.nifi.authorization.resource.Authorizable;
+import org.apache.nifi.authorization.user.NiFiUserUtils;
+import org.apache.nifi.persistence.TemplateSerializer;
+import org.apache.nifi.web.NiFiServiceFacade;
+import org.apache.nifi.web.api.dto.TemplateDTO;
+import org.apache.nifi.web.api.entity.TemplateEntity;
+
+import com.wordnik.swagger.annotations.Api;
+import com.wordnik.swagger.annotations.ApiOperation;
+import com.wordnik.swagger.annotations.ApiParam;
+import com.wordnik.swagger.annotations.ApiResponse;
+import com.wordnik.swagger.annotations.ApiResponses;
+import com.wordnik.swagger.annotations.Authorization;
 
 /**
  * RESTful endpoint for managing a Template.
@@ -168,7 +172,13 @@ public class TemplateResource extends ApplicationResource {
         }
 
         // generate the response
-        return generateOkResponse(template).header("Content-Disposition", String.format("attachment; filename=\"%s.xml\"", attachmentName)).build();
+        /*
+         * Here instead of relying on default JAXB marshalling we are simply
+         * serializing template to String (formatted, indented etc) and sending
+         * it as part of the response.
+         */
+        String serializedTemplate = new String(TemplateSerializer.serialize(template), StandardCharsets.UTF_8);
+        return generateOkResponse(serializedTemplate).header("Content-Disposition", String.format("attachment; filename=\"%s.xml\"", attachmentName)).build();
     }
 
     /**

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-api/src/main/java/org/apache/nifi/web/util/SnippetUtils.java

@@ -16,17 +16,21 @@
  */
 package org.apache.nifi.web.util;
 
+import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Random;
 import java.util.Set;
 import java.util.UUID;
 import java.util.stream.Collectors;
 
+import org.apache.commons.lang3.StringUtils;
 import org.apache.nifi.components.PropertyDescriptor;
 import org.apache.nifi.connectable.ConnectableType;
 import org.apache.nifi.connectable.Connection;
@@ -74,7 +78,7 @@ public final class SnippetUtils {
      * @return snippet
      */
     public FlowSnippetDTO populateFlowSnippet(final Snippet snippet, final boolean recurse, final boolean includeControllerServices) {
-        final FlowSnippetDTO snippetDto = new FlowSnippetDTO();
+        final FlowSnippetDTO snippetDto = new FlowSnippetDTO(true);
         final String groupId = snippet.getParentGroupId();
         final ProcessGroup processGroup = flowController.getGroup(groupId);
 
@@ -99,9 +103,12 @@ public final class SnippetUtils {
                     controllerServices.addAll(getControllerServices(processor.getProperties()));
                 }
             }
+            this.normalizeCoordinates(processors);
             snippetDto.setProcessors(processors);
         }
 
+
+
         // add any connections
         if (!snippet.getConnections().isEmpty()) {
             final Set<ConnectionDTO> connections = new LinkedHashSet<>();
@@ -559,11 +566,12 @@ public final class SnippetUtils {
      * Generates a new id for the current id that is specified. If no seed is found, a new random id will be created.
      */
     private String generateId(final String currentId, final String seed) {
-        if (seed == null) {
+        long msb = UUID.fromString(currentId).getMostSignificantBits();
-            return UUID.randomUUID().toString();
+        long lsb = StringUtils.isBlank(seed)
-        } else {
+                ? Math.abs(new Random().nextInt())
-            return UUID.nameUUIDFromBytes((currentId + seed).getBytes(StandardCharsets.UTF_8)).toString();
+                : Math.abs(ByteBuffer.wrap(seed.getBytes(StandardCharsets.UTF_8)).getInt());
-        }
+
+        return new UUID(msb, lsb).toString();
     }
 
     /* setters */
@@ -575,4 +583,30 @@ public final class SnippetUtils {
         this.flowController = flowController;
     }
 
+    /**
+     * Will normalize the coordinates of the processors to ensure their
+     * consistency across exports. It will do so by fist calculating the
+     * smallest X and smallest Y and then subtracting it from all X's and Y's of
+     * each processor ensuring that coordinates are consistent across export
+     * while preserving relative locations set by the user.
+     */
+    private void normalizeCoordinates(Collection<ProcessorDTO> processors) {
+        double smallestX = Double.MAX_VALUE;
+        double smallestY = Double.MAX_VALUE;
+        for (ProcessorDTO processor : processors) {
+            double d = processor.getPosition().getX();
+            if (d < smallestX) {
+                smallestX = d;
+            }
+            d = processor.getPosition().getY();
+            if (d < smallestY) {
+                smallestY = d;
+            }
+        }
+        for (ProcessorDTO processor : processors) {
+            processor.getPosition().setX(processor.getPosition().getX() - smallestX);
+            processor.getPosition().setY(processor.getPosition().getY() - smallestY);
+        }
+    }
+
 }

nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-api/src/test/groovy/org/apache/nifi/web/dao/impl/StandardTemplateDAOSpec.groovy

@@ -24,6 +24,8 @@ import org.apache.nifi.controller.service.ControllerServiceProvider
 import org.apache.nifi.groups.ProcessGroup
 import org.apache.nifi.web.api.dto.*
 import org.apache.nifi.web.util.SnippetUtils
+
+import spock.lang.Ignore;
 import spock.lang.Specification
 import spock.lang.Unroll
 
@@ -117,28 +119,28 @@ class StandardTemplateDAOSpec extends Specification {
         rootGroupId | oldOriginX | oldOriginY | newOriginX | newOriginY | templateId | idGenerationSeed | encodingVersion | snippet
         'g1'        | 0.0        | 0.0        | 5.0        | 5.0        | 't1'       | 'AAAA'           | null            | new FlowSnippetDTO()
         'g1'        | 10.0       | 10.0       | 5.0        | 5.0        | 't1'       | 'AAAA'           | '0.7'           | new FlowSnippetDTO(
-                processors: [new ProcessorDTO(name: 'proc1', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))])
+                processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0000-c4af042cb1559", name: 'proc1', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))])
         'g1'        | 10.0       | -10.0      | 5.0        | 5.0        | 't1'       | 'AAAA'           | null           | new FlowSnippetDTO(
-                processors: [new ProcessorDTO(name: 'proc2', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))],
+                processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0001-c4af042cb1559", name: 'proc2', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))],
                 processGroups: [
-                        new ProcessGroupDTO(
+                        new ProcessGroupDTO(id:"c81f6810-0a55-1000-0000-c4af042cb1559", 
                                 name: 'g2',
                                 position: new PositionDTO(x: 105, y: -10),
-                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(name: 'proc3', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 50, y: 60))]))])
+                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0002-c4af042cb1559", name: 'proc3', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 50, y: 60))]))])
         'g1'        | 10.0       | -10.0      | 5.0        | 5.0        | 't1'       | 'AAAA'           | '0.7'           | new FlowSnippetDTO(
-                processors: [new ProcessorDTO(name: 'proc2', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))],
+                processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0003-c4af042cb1559", name: 'proc2', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))],
                 processGroups: [
-                        new ProcessGroupDTO(
+                        new ProcessGroupDTO(id:"c81f6810-0a55-1000-0001-c4af042cb1559",
                                 name: 'g2',
                                 position: new PositionDTO(x: 105, y: -10),
-                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(name: 'proc3', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 50, y: 60))]))])
+                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0004-c4af042cb1559", name: 'proc3', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 50, y: 60))]))])
         'g1'        | 10.0       | -10.0      | 5.0        | 5.0        | 't1'       | 'AAAA'           | '1.0'           | new FlowSnippetDTO(
-                processors: [new ProcessorDTO(name: 'proc2', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))],
+                processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0005-c4af042cb1559", name: 'proc2', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 10, y: 10))],
                 processGroups: [
-                        new ProcessGroupDTO(
+                        new ProcessGroupDTO(id:"c81f6810-0a55-1000-0003-c4af042cb1559",
                                 name: 'g2',
                                 position: new PositionDTO(x: 105, y: -10),
-                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(name: 'proc3', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 50, y: 60))]))])
+                                contents: new FlowSnippetDTO(processors: [new ProcessorDTO(id:"c81f6810-0155-1000-0006-c4af042cb1559", name: 'proc3', config: new ProcessorConfigDTO(), position: new PositionDTO(x: 50, y: 60))]))])
     }
 
     def PositionDTO calculateMoveAndScalePosition(position, oldOriginX, oldOriginY, newOriginX, newOriginY, factorX, factorY) {