Remove support for internal versioning for concurrency control (#38254)

Elasticsearch has long [supported](https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-index_.html#index-versioning) compare and set (a.k.a optimistic concurrency control) operations using internal document versioning. Sadly that approach is flawed and can sometime do the wrong thing. Here's the relevant excerpt from the resiliency status page:

> When a primary has been partitioned away from the cluster there is a short period of time until it detects this. During that time it will continue indexing writes locally, thereby updating document versions. When it tries to replicate the operation, however, it will discover that it is partitioned away. It won’t acknowledge the write and will wait until the partition is resolved to negotiate with the master on how to proceed. The master will decide to either fail any replicas which failed to index the operations on the primary or tell the primary that it has to step down because a new primary has been chosen in the meantime. Since the old primary has already written documents, clients may already have read from the old primary before it shuts itself down. The version numbers of these reads may not be unique if the new primary has already accepted writes for the same document 

We recently [introduced](https://www.elastic.co/guide/en/elasticsearch/reference/6.x/optimistic-concurrency-control.html) a new sequence number based approach that doesn't suffer from this dirty reads problem. 

This commit removes support for internal versioning as a concurrency control mechanism in favor of the sequence number approach.

Relates to #1078

client/rest-high-level/src/main/java/org/elasticsearch/client/WatcherRequestConverters.java

@@ -70,7 +70,6 @@ final class WatcherRequestConverters {
 
         Request request = new Request(HttpPut.METHOD_NAME, endpoint);
         RequestConverters.Params params = new RequestConverters.Params(request)
-            .withVersion(putWatchRequest.getVersion())
             .withIfSeqNo(putWatchRequest.ifSeqNo())
             .withIfPrimaryTerm(putWatchRequest.ifPrimaryTerm());
         if (putWatchRequest.isActive() == false) {

client/rest-high-level/src/main/java/org/elasticsearch/client/watcher/PutWatchRequest.java

@@ -21,7 +21,6 @@ package org.elasticsearch.client.watcher;
 import org.elasticsearch.client.Validatable;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesReference;
-import org.elasticsearch.common.lucene.uid.Versions;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.index.seqno.SequenceNumbers;
 
@@ -43,11 +42,9 @@ public final class PutWatchRequest implements Validatable {
     private final BytesReference source;
     private final XContentType xContentType;
     private boolean active = true;
-    private long version = Versions.MATCH_ANY;
     private long ifSeqNo = SequenceNumbers.UNASSIGNED_SEQ_NO;
     private long ifPrimaryTerm = UNASSIGNED_PRIMARY_TERM;
 
-
     public PutWatchRequest(String id, BytesReference source, XContentType xContentType) {
         Objects.requireNonNull(id, "watch id is missing");
         if (isValidId(id) == false) {
@@ -95,14 +92,6 @@ public final class PutWatchRequest implements Validatable {
         return xContentType;
     }
 
-    public long getVersion() {
-        return version;
-    }
-
-    public void setVersion(long version) {
-        this.version = version;
-    }
-
     /**
      * only performs this put request if the watch's last modification was assigned the given
      * sequence number. Must be used in combination with {@link #setIfPrimaryTerm(long)}

client/rest-high-level/src/test/java/org/elasticsearch/client/RequestConvertersTests.java

@@ -768,8 +768,6 @@ public class RequestConvertersTests extends ESTestCase {
             }
         }
         setRandomWaitForActiveShards(updateRequest::waitForActiveShards, expectedParams);
-        setRandomVersion(updateRequest, expectedParams);
-        setRandomVersionType(updateRequest::versionType, expectedParams);
         setRandomIfSeqNoAndTerm(updateRequest, new HashMap<>()); // if* params are passed in the body
         if (randomBoolean()) {
             int retryOnConflict = randomIntBetween(0, 5);
@@ -911,14 +909,7 @@ public class RequestConvertersTests extends ESTestCase {
             if (randomBoolean()) {
                 docWriteRequest.routing(randomAlphaOfLength(10));
             }
-            if (randomBoolean()) {
-                if (randomBoolean()) {
-                    docWriteRequest.version(randomNonNegativeLong());
-                }
-                if (randomBoolean()) {
-                    docWriteRequest.versionType(randomFrom(VersionType.values()));
-                }
-            } else if (randomBoolean()) {
+            if (opType != DocWriteRequest.OpType.UPDATE && randomBoolean()) {
                 docWriteRequest.setIfSeqNo(randomNonNegativeLong());
                 docWriteRequest.setIfPrimaryTerm(randomLongBetween(1, 200));
             }

client/rest-high-level/src/test/java/org/elasticsearch/client/WatcherRequestConvertersTests.java

@@ -29,8 +29,8 @@ import org.elasticsearch.client.watcher.ActivateWatchRequest;
 import org.elasticsearch.client.watcher.DeactivateWatchRequest;
 import org.elasticsearch.client.watcher.DeleteWatchRequest;
 import org.elasticsearch.client.watcher.ExecuteWatchRequest;
-import org.elasticsearch.client.watcher.PutWatchRequest;
 import org.elasticsearch.client.watcher.GetWatchRequest;
+import org.elasticsearch.client.watcher.PutWatchRequest;
 import org.elasticsearch.client.watcher.StartWatchServiceRequest;
 import org.elasticsearch.client.watcher.StopWatchServiceRequest;
 import org.elasticsearch.client.watcher.WatcherStatsRequest;
@@ -88,9 +88,12 @@ public class WatcherRequestConvertersTests extends ESTestCase {
         }
 
         if (randomBoolean()) {
-            long version = randomLongBetween(10, 100);
-            putWatchRequest.setVersion(version);
-            expectedParams.put("version", String.valueOf(version));
+            long seqNo = randomNonNegativeLong();
+            long ifPrimaryTerm = randomLongBetween(1, 200);
+            putWatchRequest.setIfSeqNo(seqNo);
+            putWatchRequest.setIfPrimaryTerm(ifPrimaryTerm);
+            expectedParams.put("if_seq_no", String.valueOf(seqNo));
+            expectedParams.put("if_primary_term", String.valueOf(ifPrimaryTerm));
         }
 
         Request request = WatcherRequestConverters.putWatch(putWatchRequest);

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/CRUDDocumentationIT.java

@@ -170,7 +170,6 @@ public class CRUDDocumentationIT extends ESRestHighLevelClientTestCase {
             // tag::index-response
             String index = indexResponse.getIndex();
             String id = indexResponse.getId();
-            long version = indexResponse.getVersion();
             if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
                 // <1>
             } else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
@@ -220,7 +219,8 @@ public class CRUDDocumentationIT extends ESRestHighLevelClientTestCase {
             IndexRequest request = new IndexRequest("posts")
                 .id("1")
                 .source("field", "value")
-                .version(1);
+                .setIfSeqNo(10L)
+                .setIfPrimaryTerm(20);
             try {
                 IndexResponse response = client.index(request, RequestOptions.DEFAULT);
             } catch(ElasticsearchException e) {
@@ -432,7 +432,8 @@ public class CRUDDocumentationIT extends ESRestHighLevelClientTestCase {
             // tag::update-conflict
             UpdateRequest request = new UpdateRequest("posts", "1")
                     .doc("field", "value")
-                    .version(1);
+                    .setIfSeqNo(101L)
+                    .setIfPrimaryTerm(200L);
             try {
                 UpdateResponse updateResponse = client.update(
                         request, RequestOptions.DEFAULT);
@@ -499,9 +500,10 @@ public class CRUDDocumentationIT extends ESRestHighLevelClientTestCase {
             request.setRefreshPolicy(WriteRequest.RefreshPolicy.WAIT_UNTIL); // <1>
             request.setRefreshPolicy("wait_for");                            // <2>
             // end::update-request-refresh
-            // tag::update-request-version
-            request.version(2); // <1>
-            // end::update-request-version
+            // tag::update-request-cas
+            request.setIfSeqNo(2L); // <1>
+            request.setIfPrimaryTerm(1L); // <2>
+            // end::update-request-request-cas
             // tag::update-request-detect-noop
             request.detectNoop(false); // <1>
             // end::update-request-detect-noop
@@ -630,7 +632,7 @@ public class CRUDDocumentationIT extends ESRestHighLevelClientTestCase {
             // tag::delete-conflict
             try {
                 DeleteResponse deleteResponse = client.delete(
-                        new DeleteRequest("posts", "1").version(2),
+                    new DeleteRequest("posts", "1").setIfSeqNo(100).setIfPrimaryTerm(2),
                         RequestOptions.DEFAULT);
             } catch (ElasticsearchException exception) {
                 if (exception.status() == RestStatus.CONFLICT) {

docs/java-rest/high-level/document/update.asciidoc

@@ -140,9 +140,10 @@ include-tagged::{doc-tests-file}[{api}-request-source-exclude]
 
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
-include-tagged::{doc-tests-file}[{api}-request-version]
+include-tagged::{doc-tests-file}[{api}-request-cas]
 --------------------------------------------------
-<1> Version
+<1> ifSeqNo
+<2> ifPrimaryTerm
 
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------

docs/reference/migration/migrate_7_0/api.asciidoc

@@ -2,6 +2,22 @@
 [[breaking_70_api_changes]]
 === API changes
 
+[float]
+==== Internal Versioning is no longer supported for optimistic concurrency control
+
+Elasticsearch maintains a numeric version field for each document it stores. That field
+is incremented by one with every change to the document. Until 7.0.0 the API allowed using
+that field for optimistic concurrency control, i.e., making a write operation conditional
+on the current document version. Sadly, that approach is flawed because the value of the
+version doesn't always uniquely represent a change to the document. If a primary fails
+while handling a write operation, it may expose a version that will then be reused by the
+new primary.
+
+Due to that issue, internal versioning can no longer be used and is replaced by a new
+method based on sequence numbers. See <<optimistic-concurrency-control>> for more details.
+
+Note that the `external` versioning type is still fully supported.
+
 [float]
 ==== Camel case and underscore parameters deprecated in 6.x have been removed
 A number of duplicate parameters deprecated in 6.x have been removed from

modules/reindex/src/main/java/org/elasticsearch/index/reindex/AsyncDeleteByQueryAction.java

@@ -20,11 +20,9 @@
 package org.elasticsearch.index.reindex;
 
 import org.apache.logging.log4j.Logger;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.delete.DeleteRequest;
 import org.elasticsearch.client.ParentTaskAssigningClient;
-import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.threadpool.ThreadPool;
 
@@ -33,18 +31,10 @@ import org.elasticsearch.threadpool.ThreadPool;
  */
 public class AsyncDeleteByQueryAction extends AbstractAsyncBulkByScrollAction<DeleteByQueryRequest, TransportDeleteByQueryAction> {
 
-    private final boolean useSeqNoForCAS;
-
     public AsyncDeleteByQueryAction(BulkByScrollTask task, Logger logger, ParentTaskAssigningClient client,
                                     ThreadPool threadPool, TransportDeleteByQueryAction action, DeleteByQueryRequest request,
-                                    ScriptService scriptService, ClusterState clusterState, ActionListener<BulkByScrollResponse> listener) {
-        super(task,
-            // not all nodes support sequence number powered optimistic concurrency control, we fall back to version
-            clusterState.nodes().getMinNodeVersion().onOrAfter(Version.V_6_7_0) == false,
-            // all nodes support sequence number powered optimistic concurrency control and we can use it
-            clusterState.nodes().getMinNodeVersion().onOrAfter(Version.V_6_7_0),
-            logger, client, threadPool, action, request, listener);
-        useSeqNoForCAS = clusterState.nodes().getMinNodeVersion().onOrAfter(Version.V_6_7_0);
+                                    ScriptService scriptService, ActionListener<BulkByScrollResponse> listener) {
+        super(task, false, true, logger, client, threadPool, action, request, listener);
     }
 
     @Override
@@ -60,12 +50,8 @@ public class AsyncDeleteByQueryAction extends AbstractAsyncBulkByScrollAction<De
         delete.index(doc.getIndex());
         delete.type(doc.getType());
         delete.id(doc.getId());
-        if (useSeqNoForCAS) {
-            delete.setIfSeqNo(doc.getSeqNo());
-            delete.setIfPrimaryTerm(doc.getPrimaryTerm());
-        } else {
-            delete.version(doc.getVersion());
-        }
+        delete.setIfSeqNo(doc.getSeqNo());
+        delete.setIfPrimaryTerm(doc.getPrimaryTerm());
         return wrap(delete);
     }
 

modules/reindex/src/main/java/org/elasticsearch/index/reindex/TransportDeleteByQueryAction.java

@@ -61,7 +61,7 @@ public class TransportDeleteByQueryAction extends HandledTransportAction<DeleteB
                 ClusterState state = clusterService.state();
                 ParentTaskAssigningClient assigningClient = new ParentTaskAssigningClient(client, clusterService.localNode(),
                     bulkByScrollTask);
-                new AsyncDeleteByQueryAction(bulkByScrollTask, logger, assigningClient, threadPool, this, request, scriptService, state,
+                new AsyncDeleteByQueryAction(bulkByScrollTask, logger, assigningClient, threadPool, this, request, scriptService,
                     listener).start();
             }
         );

modules/reindex/src/main/java/org/elasticsearch/index/reindex/TransportUpdateByQueryAction.java

@@ -31,7 +31,6 @@ import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.index.VersionType;
 import org.elasticsearch.index.mapper.IdFieldMapper;
 import org.elasticsearch.index.mapper.IndexFieldMapper;
 import org.elasticsearch.index.mapper.RoutingFieldMapper;
@@ -113,13 +112,8 @@ public class TransportUpdateByQueryAction extends HandledTransportAction<UpdateB
             index.type(doc.getType());
             index.id(doc.getId());
             index.source(doc.getSource(), doc.getXContentType());
-            if (useSeqNoForCAS) {
-                index.setIfSeqNo(doc.getSeqNo());
-                index.setIfPrimaryTerm(doc.getPrimaryTerm());
-            } else {
-                index.versionType(VersionType.INTERNAL);
-                index.version(doc.getVersion());
-            }
+            index.setIfSeqNo(doc.getSeqNo());
+            index.setIfPrimaryTerm(doc.getPrimaryTerm());
             index.setPipeline(mainRequest.getPipeline());
             return wrap(index);
         }

modules/reindex/src/test/java/org/elasticsearch/index/reindex/UpdateByQueryWhileModifyingTests.java

@@ -67,7 +67,7 @@ public class UpdateByQueryWhileModifyingTests extends ReindexTestCase {
                 IndexRequestBuilder index = client().prepareIndex("test", "test", "test").setSource("test", value.get())
                         .setRefreshPolicy(IMMEDIATE);
                 /*
-                 * Update by query increments the version number so concurrent
+                 * Update by query changes the document so concurrent
                  * indexes might get version conflict exceptions so we just
                  * blindly retry.
                  */
@@ -75,7 +75,7 @@ public class UpdateByQueryWhileModifyingTests extends ReindexTestCase {
                 while (true) {
                     attempts++;
                     try {
-                        index.setVersion(get.getVersion()).get();
+                        index.setIfSeqNo(get.getSeqNo()).setIfPrimaryTerm(get.getPrimaryTerm()).get();
                         break;
                     } catch (VersionConflictEngineException e) {
                         if (attempts >= MAX_ATTEMPTS) {

rest-api-spec/src/main/resources/rest-api-spec/api/update.json

@@ -70,15 +70,6 @@
         "if_primary_term" : {
           "type" : "number",
           "description" : "only perform the update operation if the last operation that has changed the document has the specified primary term"
-        },
-        "version": {
-          "type": "number",
-          "description": "Explicit version number for concurrency control"
-        },
-        "version_type": {
-          "type": "enum",
-          "options": ["internal", "force"],
-          "description": "Specific version type"
         }
       }
     },

rest-api-spec/src/main/resources/rest-api-spec/test/create/30_internal_version.yml

@@ -1,36 +0,0 @@
----
-"Internal version":
- - skip:
-      version: " - 6.99.99"
-      reason: types are required in requests before 7.0.0
- - do:
-      create:
-          index:  test_1
-          id:     1
-          body:   { foo: bar }
-
- - match:   { _version: 1}
-
- - do:
-      catch: conflict
-      create:
-          index:  test_1
-          id:     1
-          body:   { foo: bar }
-
----
-"Internal versioning with explicit version":
- - skip:
-      version: " - 6.99.99"
-      reason: types are required in requests before 7.0.0
- - do:
-      catch: bad_request
-      create:
-          index:          test
-          id:             3
-          body:           { foo: bar }
-          version:        5
-
- - match: { status: 400 }
- - match: { error.type: action_request_validation_exception }
- - match: { error.reason: "Validation Failed: 1: create operations do not support explicit versions. use index instead;" }

rest-api-spec/src/main/resources/rest-api-spec/test/create/31_internal_version_with_types.yml

@@ -1,35 +0,0 @@
----
-"Internal version":
-
- - do:
-      create:
-          index:  test_1
-          type:   test
-          id:     1
-          body:   { foo: bar }
-
- - match:   { _version: 1}
-
- - do:
-      catch: conflict
-      create:
-          index:  test_1
-          type:   test
-          id:     1
-          body:   { foo: bar }
-
----
-"Internal versioning with explicit version":
-
- - do:
-      catch: bad_request
-      create:
-          index:          test
-          type:           test
-          id:             3
-          body:           { foo: bar }
-          version:        5
-
- - match: { status: 400 }
- - match: { error.type: action_request_validation_exception }
- - match: { error.reason: "Validation Failed: 1: create operations do not support explicit versions. use index instead;" }

rest-api-spec/src/main/resources/rest-api-spec/test/delete/20_internal_version.yml → rest-api-spec/src/main/resources/rest-api-spec/test/delete/20_cas.yml

@@ -11,19 +11,21 @@
           id:      1
           body:    { foo: bar }
 
- - match:   { _version: 1}
+ - match:   { _seq_no: 0 }
 
  - do:
       catch:       conflict
       delete:
           index:   test_1
           id:      1
-          version: 2
+          if_seq_no: 2
+          if_primary_term: 1
 
  - do:
       delete:
           index:   test_1
           id:      1
-          version: 1
+          if_seq_no: 0
+          if_primary_term: 1
 
- - match: { _version: 2 }
+ - match: { _seq_no: 1 }

rest-api-spec/src/main/resources/rest-api-spec/test/delete/21_cas_with_types.yml

@@ -0,0 +1,30 @@
+---
+"Internal version":
+
+  - do:
+      index:
+        index:   test_1
+        type:    test
+        id:      1
+        body:    { foo: bar }
+
+  - match:   { _seq_no: 0 }
+
+  - do:
+      catch:       conflict
+      delete:
+        index:   test_1
+        type:    test
+        id:      1
+        if_seq_no: 2
+        if_primary_term: 1
+
+  - do:
+      delete:
+        index:   test_1
+        type:    test
+        id:      1
+        if_seq_no: 0
+        if_primary_term: 1
+
+  - match: { _seq_no: 1 }

rest-api-spec/src/main/resources/rest-api-spec/test/delete/21_internal_version_with_types.yml

@@ -1,28 +0,0 @@
----
-"Internal version":
-
- - do:
-      index:
-          index:   test_1
-          type:    test
-          id:      1
-          body:    { foo: bar }
-
- - match:   { _version: 1}
-
- - do:
-      catch:       conflict
-      delete:
-          index:   test_1
-          type:    test
-          id:      1
-          version: 2
-
- - do:
-      delete:
-          index:   test_1
-          type:    test
-          id:      1
-          version: 1
-
- - match: { _version: 2 }

rest-api-spec/src/main/resources/rest-api-spec/test/index/30_internal_version.yml

@@ -1,36 +0,0 @@
----
-"Internal version":
-
- - skip:
-      version: " - 6.99.99"
-      reason: types are required in requests before 7.0.0
-
- - do:
-      index:
-          index:  test_1
-          id:     1
-          body:   { foo: bar }
- - match:   { _version: 1}
-
- - do:
-      index:
-          index:  test_1
-          id:     1
-          body:   { foo: bar }
- - match:   { _version: 2}
-
- - do:
-      catch:       conflict
-      index:
-          index:   test_1
-          id:      1
-          body:    { foo: bar }
-          version: 1
- - do:
-      index:
-          index:   test_1
-          id:      1
-          body:    { foo: bar }
-          version: 2
-
- - match: { _version: 3 }

rest-api-spec/src/main/resources/rest-api-spec/test/index/31_internal_version_with_types.yml

@@ -1,36 +0,0 @@
----
-"Internal version":
-
- - do:
-      index:
-          index:  test_1
-          type:   test
-          id:     1
-          body:   { foo: bar }
- - match:   { _version: 1}
-
- - do:
-      index:
-          index:  test_1
-          type:   test
-          id:     1
-          body:   { foo: bar }
- - match:   { _version: 2}
-
- - do:
-      catch:       conflict
-      index:
-          index:   test_1
-          type:    test
-          id:      1
-          body:    { foo: bar }
-          version: 1
- - do:
-      index:
-          index:   test_1
-          type:    test
-          id:      1
-          body:    { foo: bar }
-          version: 2
-
- - match: { _version: 3 }

rest-api-spec/src/main/resources/rest-api-spec/test/update/30_internal_version.yml

@@ -1,31 +0,0 @@
----
-"Internal version":
-
- - skip:
-      version: " - 6.99.99"
-      reason: types are required in requests before 7.0.0
-
- - do:
-      catch:        missing
-      update:
-          index:    test_1
-          id:       1
-          version:  1
-          body:
-            doc:    { foo: baz }
-
- - do:
-      index:
-          index:    test_1
-          id:       1
-          body:
-            doc:    { foo: baz }
-
- - do:
-      catch:        conflict
-      update:
-          index:    test_1
-          id:       1
-          version:  2
-          body:
-            doc:    { foo: baz }

rest-api-spec/src/main/resources/rest-api-spec/test/update/31_internal_version_with_types.yml

@@ -1,30 +0,0 @@
----
-"Internal version":
-
- - do:
-      catch:        missing
-      update:
-          index:    test_1
-          type:     test
-          id:       1
-          version:  1
-          body:
-            doc:    { foo: baz }
-
- - do:
-      index:
-          index:    test_1
-          type:     test
-          id:       1
-          body:
-            doc:    { foo: baz }
-
- - do:
-      catch:        conflict
-      update:
-          index:    test_1
-          type:     test
-          id:       1
-          version:  2
-          body:
-            doc:    { foo: baz }

rest-api-spec/src/main/resources/rest-api-spec/test/update/35_other_versions.yml

@@ -1,29 +0,0 @@
----
-"Not supported versions":
-
- - skip:
-      version: " - 6.99.99"
-      reason: types are required in requests before 7.0.0
-
- - do:
-      catch:            /Validation|Invalid/
-      update:
-          index:        test_1
-          id:           1
-          version:      2
-          version_type: external
-          body:
-            doc:        { foo: baz }
-            upsert:     { foo: bar }
-
- - do:
-      catch:            /Validation|Invalid/
-      update:
-          index:        test_1
-          id:           1
-          version:      2
-          version_type: external_gte
-          body:
-            doc:        { foo: baz }
-            upsert:     { foo: bar }
-

rest-api-spec/src/main/resources/rest-api-spec/test/update/36_other_versions_with_types.yml

@@ -1,27 +0,0 @@
----
-"Not supported versions":
-
- - do:
-      catch:            /Validation|Invalid/
-      update:
-          index:        test_1
-          type:         test
-          id:           1
-          version:      2
-          version_type: external
-          body:
-            doc:        { foo: baz }
-            upsert:     { foo: bar }
-
- - do:
-      catch:            /Validation|Invalid/
-      update:
-          index:        test_1
-          type:         test
-          id:           1
-          version:      2
-          version_type: external_gte
-          body:
-            doc:        { foo: baz }
-            upsert:     { foo: bar }
-

server/src/main/java/org/elasticsearch/action/DocWriteRequest.java

@@ -257,16 +257,23 @@ public interface DocWriteRequest<T> extends IndicesRequest {
 
     static ActionRequestValidationException validateSeqNoBasedCASParams(
         DocWriteRequest request, ActionRequestValidationException validationException) {
-        if (request.versionType().validateVersionForWrites(request.version()) == false) {
-            validationException = addValidationError("illegal version value [" + request.version() + "] for version type ["
-                + request.versionType().name() + "]", validationException);
+        final long version = request.version();
+        final VersionType versionType = request.versionType();
+        if (versionType.validateVersionForWrites(version) == false) {
+            validationException = addValidationError("illegal version value [" + version + "] for version type ["
+                + versionType.name() + "]", validationException);
         }
-        if (request.versionType() == VersionType.FORCE) {
+        if (versionType == VersionType.FORCE) {
             validationException = addValidationError("version type [force] may no longer be used", validationException);
         }
 
+        if (versionType == VersionType.INTERNAL && version != Versions.MATCH_ANY && version != Versions.MATCH_DELETED) {
+            validationException = addValidationError("internal versioning can not be used for optimistic concurrency control. " +
+                "Please use `if_seq_no` and `if_primary_term` instead", validationException);
+        }
+
         if (request.ifSeqNo() != UNASSIGNED_SEQ_NO && (
-            request.versionType() != VersionType.INTERNAL || request.version() != Versions.MATCH_ANY
+            versionType != VersionType.INTERNAL || version != Versions.MATCH_ANY
         )) {
             validationException = addValidationError("compare and write operations can not use versioning", validationException);
         }

server/src/main/java/org/elasticsearch/action/bulk/BulkRequest.java

@@ -46,9 +46,9 @@ import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.index.VersionType;
+import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.seqno.SequenceNumbers;
 import org.elasticsearch.rest.action.document.RestBulkAction;
-import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
 
 import java.io.IOException;
@@ -501,8 +501,11 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
                                 .create(true).setPipeline(pipeline).setIfSeqNo(ifSeqNo).setIfPrimaryTerm(ifPrimaryTerm)
                                 .source(sliceTrimmingCarriageReturn(data, from, nextMarker, xContentType), xContentType), payload);
                     } else if ("update".equals(action)) {
+                        if (version != Versions.MATCH_ANY || versionType != VersionType.INTERNAL) {
+                            throw new IllegalArgumentException("Update requests do not support versioning. " +
+                                "Please use `if_seq_no` and `if_primary_term` instead");
+                        }
                         UpdateRequest updateRequest = new UpdateRequest(index, type, id).routing(routing).retryOnConflict(retryOnConflict)
-                                .version(version).versionType(versionType)
                                 .setIfSeqNo(ifSeqNo).setIfPrimaryTerm(ifPrimaryTerm)
                                 .routing(routing);
                         // EMPTY is safe here because we never call namedObject
@@ -516,15 +519,8 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
                         }
                         IndexRequest upsertRequest = updateRequest.upsertRequest();
                         if (upsertRequest != null) {
-                            upsertRequest.version(version);
-                            upsertRequest.versionType(versionType);
                             upsertRequest.setPipeline(defaultPipeline);
                         }
-                        IndexRequest doc = updateRequest.doc();
-                        if (doc != null) {
-                            doc.version(version);
-                            doc.versionType(versionType);
-                        }
 
                         internalAdd(updateRequest, payload);
                     }

server/src/main/java/org/elasticsearch/action/search/SearchRequestBuilder.java

@@ -224,7 +224,7 @@ public class SearchRequestBuilder extends ActionRequestBuilder<SearchRequest, Se
         sourceBuilder().version(version);
         return this;
     }
-
+    
     /**
      * Should each {@link org.elasticsearch.search.SearchHit} be returned with the
      * sequence number and primary term of the last modification of the document.

server/src/main/java/org/elasticsearch/action/update/UpdateHelper.java

@@ -70,7 +70,7 @@ public class UpdateHelper {
      */
     public Result prepare(UpdateRequest request, IndexShard indexShard, LongSupplier nowInMillis) {
         final GetResult getResult = indexShard.getService().getForUpdate(
-            request.type(), request.id(), request.version(), request.versionType(), request.ifSeqNo(), request.ifPrimaryTerm());
+            request.type(), request.id(), request.ifSeqNo(), request.ifPrimaryTerm());
         return prepare(indexShard.shardId(), request, getResult, nowInMillis);
     }
 

server/src/main/java/org/elasticsearch/action/update/UpdateRequest.java

@@ -108,8 +108,6 @@ public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
 
     private FetchSourceContext fetchSourceContext;
 
-    private long version = Versions.MATCH_ANY;
-    private VersionType versionType = VersionType.INTERNAL;
     private int retryOnConflict = 0;
     private long ifSeqNo = UNASSIGNED_SEQ_NO;
     private long ifPrimaryTerm = UNASSIGNED_PRIMARY_TERM;
@@ -150,9 +148,6 @@ public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
     @Override
     public ActionRequestValidationException validate() {
         ActionRequestValidationException validationException = super.validate();
-        if (version != Versions.MATCH_ANY && upsertRequest != null) {
-            validationException = addValidationError("can't provide both upsert request and a version", validationException);
-        }
         if(upsertRequest != null && upsertRequest.version() != Versions.MATCH_ANY) {
             validationException = addValidationError("can't provide version in upsert request", validationException);
         }
@@ -163,30 +158,20 @@ public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
             validationException = addValidationError("id is missing", validationException);
         }
 
-        if (versionType != VersionType.INTERNAL) {
-            validationException = addValidationError("version type [" + versionType + "] is not supported by the update API",
-                    validationException);
-        } else {
+        validationException = DocWriteRequest.validateSeqNoBasedCASParams(this, validationException);
 
-            if (version != Versions.MATCH_ANY && retryOnConflict > 0) {
-                validationException = addValidationError("can't provide both retry_on_conflict and a specific version",
-                    validationException);
+        if (ifSeqNo != UNASSIGNED_SEQ_NO) {
+            if (retryOnConflict > 0) {
+                validationException = addValidationError("compare and write operations can not be retried", validationException);
             }
 
-            if (!versionType.validateVersionForWrites(version)) {
-                validationException = addValidationError("illegal version value [" + version + "] for version type [" +
-                    versionType.name() + "]", validationException);
+            if (docAsUpsert) {
+                validationException = addValidationError("compare and write operations can not be used with upsert", validationException);
+            }
+            if (upsertRequest != null) {
+                validationException =
+                    addValidationError("upsert requests don't support `if_seq_no` and `if_primary_term`", validationException);
             }
-        }
-
-        validationException = DocWriteRequest.validateSeqNoBasedCASParams(this, validationException);
-
-        if (ifSeqNo != UNASSIGNED_SEQ_NO && retryOnConflict > 0) {
-            validationException = addValidationError("compare and write operations can not be retried", validationException);
-        }
-
-        if (ifSeqNo != UNASSIGNED_SEQ_NO && docAsUpsert) {
-            validationException = addValidationError("compare and write operations can not be used with upsert", validationException);
         }
 
         if (script == null && doc == null) {
@@ -530,24 +515,22 @@ public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
 
     @Override
     public UpdateRequest version(long version) {
-        this.version = version;
-        return this;
+        throw new UnsupportedOperationException("update requests do not support versioning");
     }
 
     @Override
     public long version() {
-        return this.version;
+        return Versions.MATCH_ANY;
     }
 
     @Override
     public UpdateRequest versionType(VersionType versionType) {
-        this.versionType = versionType;
-        return this;
+        throw new UnsupportedOperationException("update requests do not support versioning");
     }
 
     @Override
     public VersionType versionType() {
-        return this.versionType;
+        return VersionType.INTERNAL;
     }
 
     /**
@@ -877,8 +860,14 @@ public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
             upsertRequest.readFrom(in);
         }
         docAsUpsert = in.readBoolean();
-        version = in.readLong();
-        versionType = VersionType.fromValue(in.readByte());
+        if (in.getVersion().before(Version.V_7_0_0)) {
+            long version = in.readLong();
+            VersionType versionType = VersionType.readFromStream(in);
+            if (version != Versions.MATCH_ANY || versionType != VersionType.INTERNAL) {
+                throw new UnsupportedOperationException(
+                    "versioned update requests have been removed in 7.0. Use if_seq_no and if_primary_term");
+            }
+        }
         ifSeqNo = in.readZLong();
         ifPrimaryTerm = in.readVLong();
         detectNoop = in.readBoolean();
@@ -930,8 +919,10 @@ public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
             upsertRequest.writeTo(out);
         }
         out.writeBoolean(docAsUpsert);
-        out.writeLong(version);
-        out.writeByte(versionType.getValue());
+        if (out.getVersion().before(Version.V_7_0_0)) {
+            out.writeLong(Versions.MATCH_ANY);
+            out.writeByte(VersionType.INTERNAL.getValue());
+        }
         out.writeZLong(ifSeqNo);
         out.writeVLong(ifPrimaryTerm);
         out.writeBoolean(detectNoop);

server/src/main/java/org/elasticsearch/index/get/ShardGetService.java

@@ -25,6 +25,7 @@ import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.document.DocumentField;
+import org.elasticsearch.common.lucene.uid.Versions;
 import org.elasticsearch.common.lucene.uid.VersionsAndSeqNoResolver.DocIdAndVersion;
 import org.elasticsearch.common.metrics.CounterMetric;
 import org.elasticsearch.common.metrics.MeanMetric;
@@ -102,9 +103,9 @@ public final class ShardGetService extends AbstractIndexShardComponent {
         }
     }
 
-    public GetResult getForUpdate(String type, String id, long version, VersionType versionType, long ifSeqNo, long ifPrimaryTerm) {
-        return get(type, id, new String[]{RoutingFieldMapper.NAME}, true, version, versionType, ifSeqNo, ifPrimaryTerm,
-            FetchSourceContext.FETCH_SOURCE, true);
+    public GetResult getForUpdate(String type, String id, long ifSeqNo, long ifPrimaryTerm) {
+        return get(type, id, new String[]{RoutingFieldMapper.NAME}, true,
+            Versions.MATCH_ANY, VersionType.INTERNAL, ifSeqNo, ifPrimaryTerm, FetchSourceContext.FETCH_SOURCE, true);
     }
 
     /**

server/src/main/java/org/elasticsearch/rest/action/document/RestUpdateAction.java

@@ -83,8 +83,6 @@ public class RestUpdateAction extends BaseRestHandler {
         }
 
         updateRequest.retryOnConflict(request.paramAsInt("retry_on_conflict", updateRequest.retryOnConflict()));
-        updateRequest.version(RestActions.parseVersion(request));
-        updateRequest.versionType(VersionType.fromString(request.param("version_type"), updateRequest.versionType()));
 
         updateRequest.setIfSeqNo(request.paramAsLong("if_seq_no", updateRequest.ifSeqNo()));
         updateRequest.setIfPrimaryTerm(request.paramAsLong("if_primary_term", updateRequest.ifPrimaryTerm()));

server/src/test/java/org/elasticsearch/action/bulk/BulkRequestTests.java

@@ -311,7 +311,7 @@ public class BulkRequestTests extends ESTestCase {
         assertWarnings(RestBulkAction.TYPES_DEPRECATION_MESSAGE);                
     }
 
-    public void testToValidateUpsertRequestAndVersionInBulkRequest() throws IOException {
+    public void testToValidateUpsertRequestAndCASInBulkRequest() throws IOException {
         XContentType xContentType = XContentType.SMILE;
         BytesReference data;
         try (BytesStreamOutput out = new BytesStreamOutput()) {
@@ -321,7 +321,8 @@ public class BulkRequestTests extends ESTestCase {
                 builder.field("_index", "index");
                 builder.field("_type", "type");
                 builder.field("_id", "id");
-                builder.field("version", 1L);
+                builder.field("if_seq_no", 1L);
+                builder.field("if_primary_term", 100L);
                 builder.endObject();
                 builder.endObject();
             }
@@ -330,7 +331,8 @@ public class BulkRequestTests extends ESTestCase {
                 builder.startObject();
                 builder.startObject("doc").endObject();
                 Map<String,Object> values = new HashMap<>();
-                values.put("version", 2L);
+                values.put("if_seq_no", 1L);
+                values.put("if_primary_term", 100L);
                 values.put("_index", "index");
                 values.put("_type", "type");
                 builder.field("upsert", values);
@@ -341,8 +343,7 @@ public class BulkRequestTests extends ESTestCase {
         }
         BulkRequest bulkRequest = new BulkRequest();
         bulkRequest.add(data, null, null, xContentType);
-        assertThat(bulkRequest.validate().validationErrors(), contains("can't provide both upsert request and a version",
-            "can't provide version in upsert request"));
+        assertThat(bulkRequest.validate().validationErrors(), contains("upsert requests don't support `if_seq_no` and `if_primary_term`"));
         //This test's JSON contains outdated references to types
         assertWarnings(RestBulkAction.TYPES_DEPRECATION_MESSAGE);        
     }

server/src/test/java/org/elasticsearch/action/bulk/BulkWithUpdatesIT.java

@@ -31,6 +31,7 @@ import org.elasticsearch.action.update.UpdateRequest;
 import org.elasticsearch.action.update.UpdateRequestBuilder;
 import org.elasticsearch.action.update.UpdateResponse;
 import org.elasticsearch.client.Requests;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.index.VersionType;
@@ -195,8 +196,8 @@ public class BulkWithUpdatesIT extends ESIntegTestCase {
         assertThat(((Number) getResponse.getSource().get("field")).longValue(), equalTo(4L));
     }
 
-    public void testBulkVersioning() throws Exception {
-        createIndex("test");
+    public void testBulkWithCAS() throws Exception {
+        createIndex("test", Settings.builder().put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1).build());
         ensureGreen();
         BulkResponse bulkResponse = client().prepareBulk()
                 .add(client().prepareIndex("test", "type", "1").setCreate(true).setSource("field", "1"))
@@ -204,20 +205,22 @@ public class BulkWithUpdatesIT extends ESIntegTestCase {
                 .add(client().prepareIndex("test", "type", "1").setSource("field", "2")).get();
 
         assertEquals(DocWriteResponse.Result.CREATED, bulkResponse.getItems()[0].getResponse().getResult());
-        assertThat(bulkResponse.getItems()[0].getResponse().getVersion(), equalTo(1L));
+        assertThat(bulkResponse.getItems()[0].getResponse().getSeqNo(), equalTo(0L));
         assertEquals(DocWriteResponse.Result.CREATED, bulkResponse.getItems()[1].getResponse().getResult());
-        assertThat(bulkResponse.getItems()[1].getResponse().getVersion(), equalTo(1L));
+        assertThat(bulkResponse.getItems()[1].getResponse().getSeqNo(), equalTo(1L));
         assertEquals(DocWriteResponse.Result.UPDATED, bulkResponse.getItems()[2].getResponse().getResult());
-        assertThat(bulkResponse.getItems()[2].getResponse().getVersion(), equalTo(2L));
+        assertThat(bulkResponse.getItems()[2].getResponse().getSeqNo(), equalTo(2L));
 
         bulkResponse = client().prepareBulk()
-                .add(client().prepareUpdate("test", "type", "1").setVersion(4L).setDoc(Requests.INDEX_CONTENT_TYPE, "field", "2"))
+                .add(client().prepareUpdate("test", "type", "1").setIfSeqNo(40L).setIfPrimaryTerm(20)
+                    .setDoc(Requests.INDEX_CONTENT_TYPE, "field", "2"))
                 .add(client().prepareUpdate("test", "type", "2").setDoc(Requests.INDEX_CONTENT_TYPE, "field", "2"))
-                .add(client().prepareUpdate("test", "type", "1").setVersion(2L).setDoc(Requests.INDEX_CONTENT_TYPE, "field", "3")).get();
+                .add(client().prepareUpdate("test", "type", "1").setIfSeqNo(2L).setIfPrimaryTerm(1)
+                    .setDoc(Requests.INDEX_CONTENT_TYPE, "field", "3")).get();
 
         assertThat(bulkResponse.getItems()[0].getFailureMessage(), containsString("version conflict"));
-        assertThat(bulkResponse.getItems()[1].getResponse().getVersion(), equalTo(2L));
-        assertThat(bulkResponse.getItems()[2].getResponse().getVersion(), equalTo(3L));
+        assertThat(bulkResponse.getItems()[1].getResponse().getSeqNo(), equalTo(3L));
+        assertThat(bulkResponse.getItems()[2].getResponse().getSeqNo(), equalTo(4L));
 
         bulkResponse = client().prepareBulk()
                 .add(client().prepareIndex("test", "type", "e1")
@@ -237,9 +240,9 @@ public class BulkWithUpdatesIT extends ESIntegTestCase {
 
         bulkResponse = client().prepareBulk()
                 .add(client().prepareUpdate("test", "type", "e1")
-                        .setDoc(Requests.INDEX_CONTENT_TYPE, "field", "2").setVersion(10)) // INTERNAL
+                        .setDoc(Requests.INDEX_CONTENT_TYPE, "field", "2").setIfSeqNo(10L).setIfPrimaryTerm(1))
                 .add(client().prepareUpdate("test", "type", "e1")
-                        .setDoc(Requests.INDEX_CONTENT_TYPE, "field", "3").setVersion(13).setVersionType(VersionType.INTERNAL))
+                        .setDoc(Requests.INDEX_CONTENT_TYPE, "field", "3").setIfSeqNo(20L).setIfPrimaryTerm(1))
                 .get();
 
         assertThat(bulkResponse.getItems()[0].getFailureMessage(), containsString("version conflict"));
@@ -471,7 +474,7 @@ public class BulkWithUpdatesIT extends ESIntegTestCase {
                     return;
                 }
                 BulkRequestBuilder requestBuilder = client().prepareBulk();
-                requestBuilder.add(client().prepareUpdate("test", "type", "1").setVersion(1)
+                requestBuilder.add(client().prepareUpdate("test", "type", "1").setIfSeqNo(0L).setIfPrimaryTerm(1)
                     .setDoc(Requests.INDEX_CONTENT_TYPE, "field", threadID));
                 responses[threadID] = requestBuilder.get();
 

server/src/test/java/org/elasticsearch/action/update/UpdateRequestTests.java

@@ -500,12 +500,14 @@ public class UpdateRequestTests extends ESTestCase {
         assertToXContentEquivalent(originalBytes, finalBytes, xContentType);
     }
 
-    public void testToValidateUpsertRequestAndVersion() {
+    public void testToValidateUpsertRequestAndCAS() {
         UpdateRequest updateRequest = new UpdateRequest("index", "type", "id");
-        updateRequest.version(1L);
+        updateRequest.setIfSeqNo(1L);
+        updateRequest.setIfPrimaryTerm(1L);
         updateRequest.doc("{}", XContentType.JSON);
         updateRequest.upsert(new IndexRequest("index","type", "id"));
-        assertThat(updateRequest.validate().validationErrors(), contains("can't provide both upsert request and a version"));
+        assertThat(updateRequest.validate().validationErrors(),
+            contains("upsert requests don't support `if_seq_no` and `if_primary_term`"));
     }
 
     public void testToValidateUpsertRequestWithVersion() {

server/src/test/java/org/elasticsearch/index/shard/ShardGetServiceTests.java

@@ -22,7 +22,6 @@ import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentType;
-import org.elasticsearch.index.VersionType;
 import org.elasticsearch.index.engine.Engine;
 import org.elasticsearch.index.engine.VersionConflictEngineException;
 import org.elasticsearch.index.get.GetResult;
@@ -31,7 +30,6 @@ import org.elasticsearch.index.mapper.RoutingFieldMapper;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
-import static org.elasticsearch.common.lucene.uid.Versions.MATCH_ANY;
 import static org.elasticsearch.index.seqno.SequenceNumbers.UNASSIGNED_PRIMARY_TERM;
 import static org.elasticsearch.index.seqno.SequenceNumbers.UNASSIGNED_SEQ_NO;
 
@@ -51,8 +49,7 @@ public class ShardGetServiceTests extends IndexShardTestCase {
         recoverShardFromStore(primary);
         Engine.IndexResult test = indexDoc(primary, "test", "0", "{\"foo\" : \"bar\"}");
         assertTrue(primary.getEngine().refreshNeeded());
-        GetResult testGet = primary.getService().getForUpdate(
-            "test", "0", test.getVersion(), VersionType.INTERNAL, UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
+        GetResult testGet = primary.getService().getForUpdate("test", "0", UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
         assertFalse(testGet.getFields().containsKey(RoutingFieldMapper.NAME));
         assertEquals(new String(testGet.source(), StandardCharsets.UTF_8), "{\"foo\" : \"bar\"}");
         try (Engine.Searcher searcher = primary.getEngine().acquireSearcher("test", Engine.SearcherScope.INTERNAL)) {
@@ -61,8 +58,7 @@ public class ShardGetServiceTests extends IndexShardTestCase {
 
         Engine.IndexResult test1 = indexDoc(primary, "test", "1", "{\"foo\" : \"baz\"}",  XContentType.JSON, "foobar");
         assertTrue(primary.getEngine().refreshNeeded());
-        GetResult testGet1 = primary.getService().getForUpdate(
-            "test", "1", test1.getVersion(), VersionType.INTERNAL, UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
+        GetResult testGet1 = primary.getService().getForUpdate("test", "1", UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
         assertEquals(new String(testGet1.source(), StandardCharsets.UTF_8), "{\"foo\" : \"baz\"}");
         assertTrue(testGet1.getFields().containsKey(RoutingFieldMapper.NAME));
         assertEquals("foobar", testGet1.getFields().get(RoutingFieldMapper.NAME).getValue());
@@ -77,20 +73,19 @@ public class ShardGetServiceTests extends IndexShardTestCase {
         // now again from the reader
         Engine.IndexResult test2 = indexDoc(primary, "test", "1", "{\"foo\" : \"baz\"}",  XContentType.JSON, "foobar");
         assertTrue(primary.getEngine().refreshNeeded());
-        testGet1 = primary.getService().getForUpdate("test", "1", test2.getVersion(), VersionType.INTERNAL,
-            UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
+        testGet1 = primary.getService().getForUpdate("test", "1", UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
         assertEquals(new String(testGet1.source(), StandardCharsets.UTF_8), "{\"foo\" : \"baz\"}");
         assertTrue(testGet1.getFields().containsKey(RoutingFieldMapper.NAME));
         assertEquals("foobar", testGet1.getFields().get(RoutingFieldMapper.NAME).getValue());
 
         final long primaryTerm = primary.getOperationPrimaryTerm();
-        testGet1 = primary.getService().getForUpdate("test", "1", MATCH_ANY, VersionType.INTERNAL, test2.getSeqNo(), primaryTerm);
+        testGet1 = primary.getService().getForUpdate("test", "1", test2.getSeqNo(), primaryTerm);
         assertEquals(new String(testGet1.source(), StandardCharsets.UTF_8), "{\"foo\" : \"baz\"}");
 
         expectThrows(VersionConflictEngineException.class, () ->
-            primary.getService().getForUpdate("test", "1", MATCH_ANY, VersionType.INTERNAL, test2.getSeqNo() + 1, primaryTerm));
+            primary.getService().getForUpdate("test", "1", test2.getSeqNo() + 1, primaryTerm));
         expectThrows(VersionConflictEngineException.class, () ->
-            primary.getService().getForUpdate("test", "1", MATCH_ANY, VersionType.INTERNAL, test2.getSeqNo(), primaryTerm + 1));
+            primary.getService().getForUpdate("test", "1", test2.getSeqNo(), primaryTerm + 1));
         closeShards(primary);
     }
 
@@ -108,16 +103,13 @@ public class ShardGetServiceTests extends IndexShardTestCase {
         Engine.IndexResult indexResult = indexDoc(shard, "some_type", "0", "{\"foo\" : \"bar\"}");
         assertTrue(indexResult.isCreated());
 
-        GetResult getResult = shard.getService().getForUpdate(
-            "some_type", "0", MATCH_ANY, VersionType.INTERNAL, UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
+        GetResult getResult = shard.getService().getForUpdate("some_type", "0", UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
         assertTrue(getResult.isExists());
 
-        getResult = shard.getService().getForUpdate(
-            "some_other_type", "0", MATCH_ANY, VersionType.INTERNAL, UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
+        getResult = shard.getService().getForUpdate("some_other_type", "0", UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
         assertFalse(getResult.isExists());
 
-        getResult = shard.getService().getForUpdate(
-            "_doc", "0", MATCH_ANY, VersionType.INTERNAL, UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
+        getResult = shard.getService().getForUpdate("_doc", "0", UNASSIGNED_SEQ_NO, UNASSIGNED_PRIMARY_TERM);
         assertTrue(getResult.isExists());
 
         closeShards(shard);

server/src/test/java/org/elasticsearch/indices/settings/UpdateSettingsIT.java

@@ -21,6 +21,7 @@ package org.elasticsearch.indices.settings;
 
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
 import org.elasticsearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.elasticsearch.action.delete.DeleteResponse;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.Priority;
 import org.elasticsearch.common.settings.Setting;
@@ -436,17 +437,20 @@ public class UpdateSettingsIT extends ESIntegTestCase {
 
     public void testEngineGCDeletesSetting() throws InterruptedException {
         createIndex("test");
-        client().prepareIndex("test", "type", "1").setSource("f", 1).get(); // set version to 1
-        client().prepareDelete("test", "type", "1").get(); // sets version to 2
-        // delete is still in cache this should work & set version to 3
-        client().prepareIndex("test", "type", "1").setSource("f", 2).setVersion(2).get();
+        client().prepareIndex("test", "type", "1").setSource("f", 1).get();
+        DeleteResponse response = client().prepareDelete("test", "type", "1").get();
+        long seqNo = response.getSeqNo();
+        long primaryTerm = response.getPrimaryTerm();
+        // delete is still in cache this should work
+        client().prepareIndex("test", "type", "1").setSource("f", 2).setIfSeqNo(seqNo).setIfPrimaryTerm(primaryTerm).get();
         client().admin().indices().prepareUpdateSettings("test").setSettings(Settings.builder().put("index.gc_deletes", 0)).get();
 
-        client().prepareDelete("test", "type", "1").get(); // sets version to 4
+        response = client().prepareDelete("test", "type", "1").get();
+        seqNo = response.getSeqNo();
         Thread.sleep(300); // wait for cache time to change TODO: this needs to be solved better. To be discussed.
         // delete is should not be in cache
-        assertThrows(client().prepareIndex("test", "type", "1").setSource("f", 3)
-            .setVersion(4), VersionConflictEngineException.class);
+        assertThrows(client().prepareIndex("test", "type", "1").setSource("f", 3).setIfSeqNo(seqNo).setIfPrimaryTerm(primaryTerm),
+            VersionConflictEngineException.class);
 
     }
 

server/src/test/java/org/elasticsearch/versioning/SimpleVersioningIT.java

@@ -213,11 +213,11 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         }
     }
 
-    public void testInternalVersioningInitialDelete() throws Exception {
+    public void testCompareAndSetInitialDelete() throws Exception {
         createIndex("test");
         ensureGreen();
 
-        assertThrows(client().prepareDelete("test", "type", "1").setVersion(17).execute(),
+        assertThrows(client().prepareDelete("test", "type", "1").setIfSeqNo(17).setIfPrimaryTerm(10).execute(),
                 VersionConflictEngineException.class);
 
         IndexResponse indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_1")
@@ -225,63 +225,6 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         assertThat(indexResponse.getVersion(), equalTo(1L));
     }
 
-    public void testInternalVersioning() throws Exception {
-        createIndex("test");
-        ensureGreen();
-
-        IndexResponse indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").execute().actionGet();
-        assertThat(indexResponse.getVersion(), equalTo(1L));
-
-        indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_2").setVersion(1).execute().actionGet();
-        assertThat(indexResponse.getVersion(), equalTo(2L));
-
-        assertThrows(
-                client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").setVersion(1).execute(),
-                VersionConflictEngineException.class);
-
-        assertThrows(
-                client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").setVersion(1).execute(),
-                VersionConflictEngineException.class);
-
-        assertThrows(
-                client().prepareIndex("test", "type", "1").setCreate(true).setSource("field1", "value1_1").execute(),
-                VersionConflictEngineException.class);
-
-
-        assertThrows(client().prepareDelete("test", "type", "1").setVersion(1).execute(), VersionConflictEngineException.class);
-        assertThrows(client().prepareDelete("test", "type", "1").setVersion(1).execute(), VersionConflictEngineException.class);
-
-        client().admin().indices().prepareRefresh().execute().actionGet();
-        for (int i = 0; i < 10; i++) {
-            assertThat(client().prepareGet("test", "type", "1").execute().actionGet().getVersion(), equalTo(2L));
-        }
-
-        // search with versioning
-        for (int i = 0; i < 10; i++) {
-            SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setVersion(true).execute().actionGet();
-            assertThat(searchResponse.getHits().getAt(0).getVersion(), equalTo(2L));
-        }
-
-        // search without versioning
-        for (int i = 0; i < 10; i++) {
-            SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).execute().actionGet();
-            assertThat(searchResponse.getHits().getAt(0).getVersion(), equalTo(Versions.NOT_FOUND));
-        }
-
-        DeleteResponse deleteResponse = client().prepareDelete("test", "type", "1").setVersion(2).execute().actionGet();
-        assertEquals(DocWriteResponse.Result.DELETED, deleteResponse.getResult());
-        assertThat(deleteResponse.getVersion(), equalTo(3L));
-
-        assertThrows(client().prepareDelete("test", "type", "1").setVersion(2).execute(), VersionConflictEngineException.class);
-
-
-        // This is intricate - the object was deleted but a delete transaction was with the right version. We add another one
-        // and thus the transaction is increased.
-        deleteResponse = client().prepareDelete("test", "type", "1").setVersion(3).execute().actionGet();
-        assertEquals(DocWriteResponse.Result.NOT_FOUND, deleteResponse.getResult());
-        assertThat(deleteResponse.getVersion(), equalTo(4L));
-    }
-
     public void testCompareAndSet() {
         createIndex("test");
         ensureGreen();
@@ -290,7 +233,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         assertThat(indexResponse.getSeqNo(), equalTo(0L));
         assertThat(indexResponse.getPrimaryTerm(), equalTo(1L));
 
-        indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_2").setVersion(1).execute().actionGet();
+        indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_2").setIfSeqNo(0L).setIfPrimaryTerm(1).get();
         assertThat(indexResponse.getSeqNo(), equalTo(1L));
         assertThat(indexResponse.getPrimaryTerm(), equalTo(1L));
 
@@ -353,25 +296,21 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         createIndex("test");
         ensureGreen();
 
-        IndexResponse indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").execute().actionGet();
-        assertThat(indexResponse.getVersion(), equalTo(1L));
+        IndexResponse indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").get();
+        assertThat(indexResponse.getSeqNo(), equalTo(0L));
 
         client().admin().indices().prepareFlush().execute().actionGet();
-        indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_2").setVersion(1).execute().actionGet();
-        assertThat(indexResponse.getVersion(), equalTo(2L));
+        indexResponse = client().prepareIndex("test", "type", "1").setSource("field1", "value1_2").setIfSeqNo(0).setIfPrimaryTerm(1).get();
+        assertThat(indexResponse.getSeqNo(), equalTo(1L));
 
         client().admin().indices().prepareFlush().execute().actionGet();
-        assertThrows(client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").setVersion(1).execute(),
-                VersionConflictEngineException.class);
-
-        assertThrows(client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").setVersion(1).execute(),
+        assertThrows(client().prepareIndex("test", "type", "1").setSource("field1", "value1_1").setIfSeqNo(0).setIfPrimaryTerm(1),
                 VersionConflictEngineException.class);
 
-        assertThrows(client().prepareIndex("test", "type", "1").setCreate(true).setSource("field1", "value1_1").execute(),
+        assertThrows(client().prepareIndex("test", "type", "1").setCreate(true).setSource("field1", "value1_1"),
                 VersionConflictEngineException.class);
 
-        assertThrows(client().prepareDelete("test", "type", "1").setVersion(1).execute(), VersionConflictEngineException.class);
-        assertThrows(client().prepareDelete("test", "type", "1").setVersion(1).execute(), VersionConflictEngineException.class);
+        assertThrows(client().prepareDelete("test", "type", "1").setIfSeqNo(0).setIfPrimaryTerm(1), VersionConflictEngineException.class);
 
         for (int i = 0; i < 10; i++) {
             assertThat(client().prepareGet("test", "type", "1").execute().actionGet().getVersion(), equalTo(2L));
@@ -380,10 +319,11 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         client().admin().indices().prepareRefresh().execute().actionGet();
 
         for (int i = 0; i < 10; i++) {
-            SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setVersion(true).
+            SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setVersion(true).seqNoAndPrimaryTerm(true).
             execute().actionGet();
             assertHitCount(searchResponse, 1);
             assertThat(searchResponse.getHits().getAt(0).getVersion(), equalTo(2L));
+            assertThat(searchResponse.getHits().getAt(0).getSeqNo(), equalTo(1L));
         }
     }
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportOpenJobAction.java

@@ -495,7 +495,7 @@ public class TransportOpenJobAction extends TransportMasterNodeAction<OpenJobAct
     private void clearJobFinishedTime(String jobId, ActionListener<AcknowledgedResponse> listener) {
         JobUpdate update = new JobUpdate.Builder(jobId).setClearFinishTime(true).build();
 
-        jobConfigProvider.updateJob(jobId, update, null, clusterService.state().nodes().getMinNodeVersion(), ActionListener.wrap(
+        jobConfigProvider.updateJob(jobId, update, null, ActionListener.wrap(
                 job -> listener.onResponse(new AcknowledgedResponse(true)),
                 e  -> {
                     logger.error("[" + jobId + "] Failed to clear finished_time", e);

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportUpdateDatafeedAction.java

@@ -87,7 +87,7 @@ public class TransportUpdateDatafeedAction extends TransportMasterNodeAction<Upd
 
         CheckedConsumer<Boolean, Exception> updateConsumer = ok -> {
             datafeedConfigProvider.updateDatefeedConfig(request.getUpdate().getId(), request.getUpdate(), headers,
-                    jobConfigProvider::validateDatafeedJob, clusterService.state().nodes().getMinNodeVersion(),
+                    jobConfigProvider::validateDatafeedJob,
                     ActionListener.wrap(
                             updatedConfig -> listener.onResponse(new PutDatafeedAction.Response(updatedConfig)),
                             listener::onFailure

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportUpdateFilterAction.java

@@ -6,7 +6,6 @@
 package org.elasticsearch.xpack.ml.action;
 
 import org.elasticsearch.ResourceNotFoundException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.get.GetAction;
 import org.elasticsearch.action.get.GetRequest;
@@ -54,7 +53,6 @@ public class TransportUpdateFilterAction extends HandledTransportAction<UpdateFi
 
     private final Client client;
     private final JobManager jobManager;
-    private final ClusterService clusterService;
 
     @Inject
     public TransportUpdateFilterAction(TransportService transportService, ActionFilters actionFilters, Client client,
@@ -63,19 +61,18 @@ public class TransportUpdateFilterAction extends HandledTransportAction<UpdateFi
             (Supplier<UpdateFilterAction.Request>) UpdateFilterAction.Request::new);
         this.client = client;
         this.jobManager = jobManager;
-        this.clusterService = clusterService;
     }
 
     @Override
     protected void doExecute(Task task, UpdateFilterAction.Request request, ActionListener<PutFilterAction.Response> listener) {
-        ActionListener<FilterWithVersion> filterListener = ActionListener.wrap(filterWithVersion -> {
+        ActionListener<FilterWithSeqNo> filterListener = ActionListener.wrap(filterWithVersion -> {
             updateFilter(filterWithVersion, request, listener);
         }, listener::onFailure);
 
         getFilterWithVersion(request.getFilterId(), filterListener);
     }
 
-    private void updateFilter(FilterWithVersion filterWithVersion, UpdateFilterAction.Request request,
+    private void updateFilter(FilterWithSeqNo filterWithVersion, UpdateFilterAction.Request request,
                               ActionListener<PutFilterAction.Response> listener) {
         MlFilter filter = filterWithVersion.filter;
 
@@ -100,19 +97,15 @@ public class TransportUpdateFilterAction extends HandledTransportAction<UpdateFi
 
         MlFilter updatedFilter = MlFilter.builder(filter.getId()).setDescription(description).setItems(items).build();
         indexUpdatedFilter(
-            updatedFilter, filterWithVersion.version, filterWithVersion.seqNo, filterWithVersion.primaryTerm, request, listener);
+            updatedFilter, filterWithVersion.seqNo, filterWithVersion.primaryTerm, request, listener);
     }
 
-    private void indexUpdatedFilter(MlFilter filter, final long version, final long seqNo, final long primaryTerm,
+    private void indexUpdatedFilter(MlFilter filter, final long seqNo, final long primaryTerm,
                                     UpdateFilterAction.Request request,
                                     ActionListener<PutFilterAction.Response> listener) {
         IndexRequest indexRequest = new IndexRequest(MlMetaIndex.INDEX_NAME, MlMetaIndex.TYPE, filter.documentId());
-        if (clusterService.state().nodes().getMinNodeVersion().onOrAfter(Version.V_6_7_0)) {
-            indexRequest.setIfSeqNo(seqNo);
-            indexRequest.setIfPrimaryTerm(primaryTerm);
-        } else {
-            indexRequest.version(version);
-        }
+        indexRequest.setIfSeqNo(seqNo);
+        indexRequest.setIfPrimaryTerm(primaryTerm);
         indexRequest.setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE);
 
         try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
@@ -145,7 +138,7 @@ public class TransportUpdateFilterAction extends HandledTransportAction<UpdateFi
         });
     }
 
-    private void getFilterWithVersion(String filterId, ActionListener<FilterWithVersion> listener) {
+    private void getFilterWithVersion(String filterId, ActionListener<FilterWithSeqNo> listener) {
         GetRequest getRequest = new GetRequest(MlMetaIndex.INDEX_NAME, MlMetaIndex.TYPE, MlFilter.documentId(filterId));
         executeAsyncWithOrigin(client, ML_ORIGIN, GetAction.INSTANCE, getRequest, new ActionListener<GetResponse>() {
             @Override
@@ -157,7 +150,7 @@ public class TransportUpdateFilterAction extends HandledTransportAction<UpdateFi
                              XContentParser parser = XContentFactory.xContent(XContentType.JSON)
                                      .createParser(NamedXContentRegistry.EMPTY, LoggingDeprecationHandler.INSTANCE, stream)) {
                             MlFilter filter = MlFilter.LENIENT_PARSER.apply(parser, null).build();
-                            listener.onResponse(new FilterWithVersion(filter, getDocResponse));
+                            listener.onResponse(new FilterWithSeqNo(filter, getDocResponse));
                         }
                     } else {
                         this.onFailure(new ResourceNotFoundException(Messages.getMessage(Messages.FILTER_NOT_FOUND, filterId)));
@@ -174,16 +167,14 @@ public class TransportUpdateFilterAction extends HandledTransportAction<UpdateFi
         });
     }
 
-    private static class FilterWithVersion {
+    private static class FilterWithSeqNo {
 
         private final MlFilter filter;
-        private final long version;
         private final long seqNo;
         private final long primaryTerm;
 
-        private  FilterWithVersion(MlFilter filter, GetResponse getDocResponse) {
+        private FilterWithSeqNo(MlFilter filter, GetResponse getDocResponse) {
             this.filter = filter;
-            this.version = getDocResponse.getVersion();
             this.seqNo = getDocResponse.getSeqNo();
             this.primaryTerm = getDocResponse.getPrimaryTerm();
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/persistence/DatafeedConfigProvider.java

@@ -8,7 +8,6 @@ package org.elasticsearch.xpack.ml.datafeed.persistence;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.DocWriteRequest;
 import org.elasticsearch.action.DocWriteResponse;
@@ -264,13 +263,11 @@ public class DatafeedConfigProvider {
      * @param headers Datafeed headers applied with the update
      * @param validator BiConsumer that accepts the updated config and can perform
      *                  extra validations. {@code validator} must call the passed listener
-     * @param minClusterNodeVersion minimum version of nodes in cluster
      * @param updatedConfigListener Updated datafeed config listener
      */
     public void updateDatefeedConfig(String datafeedId, DatafeedUpdate update, Map<String, String> headers,
-                          BiConsumer<DatafeedConfig, ActionListener<Boolean>> validator,
-                          Version minClusterNodeVersion,
-                          ActionListener<DatafeedConfig> updatedConfigListener) {
+                                     BiConsumer<DatafeedConfig, ActionListener<Boolean>> validator,
+                                     ActionListener<DatafeedConfig> updatedConfigListener) {
         GetRequest getRequest = new GetRequest(AnomalyDetectorsIndex.configIndexName(),
                 ElasticsearchMappings.DOC_TYPE, DatafeedConfig.documentId(datafeedId));
 
@@ -304,7 +301,7 @@ public class DatafeedConfigProvider {
 
                 ActionListener<Boolean> validatedListener = ActionListener.wrap(
                         ok -> {
-                            indexUpdatedConfig(updatedConfig, version, seqNo, primaryTerm, minClusterNodeVersion, ActionListener.wrap(
+                            indexUpdatedConfig(updatedConfig, seqNo, primaryTerm, ActionListener.wrap(
                                     indexResponse -> {
                                         assert indexResponse.getResult() == DocWriteResponse.Result.UPDATED;
                                         updatedConfigListener.onResponse(updatedConfig);
@@ -324,8 +321,8 @@ public class DatafeedConfigProvider {
         });
     }
 
-    private void indexUpdatedConfig(DatafeedConfig updatedConfig, long version, long seqNo, long primaryTerm,
-                                    Version minClusterNodeVersion, ActionListener<IndexResponse> listener) {
+    private void indexUpdatedConfig(DatafeedConfig updatedConfig, long seqNo, long primaryTerm,
+                                    ActionListener<IndexResponse> listener) {
         try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
             XContentBuilder updatedSource = updatedConfig.toXContent(builder, new ToXContent.MapParams(TO_XCONTENT_PARAMS));
             IndexRequestBuilder indexRequest = client.prepareIndex(AnomalyDetectorsIndex.configIndexName(),
@@ -333,12 +330,8 @@ public class DatafeedConfigProvider {
                     .setSource(updatedSource)
                     .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE);
 
-            if (minClusterNodeVersion.onOrAfter(Version.V_6_7_0)) {
-                indexRequest.setIfSeqNo(seqNo);
-                indexRequest.setIfPrimaryTerm(primaryTerm);
-            } else {
-                indexRequest.setVersion(version);
-            }
+            indexRequest.setIfSeqNo(seqNo);
+            indexRequest.setIfPrimaryTerm(primaryTerm);
 
             executeAsyncWithOrigin(client, ML_ORIGIN, IndexAction.INSTANCE, indexRequest.request(), listener);
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java

@@ -333,7 +333,7 @@ public class JobManager {
 
         Runnable doUpdate = () -> {
                 jobConfigProvider.updateJobWithValidation(request.getJobId(), request.getJobUpdate(), maxModelMemoryLimit,
-                        this::validate, clusterService.state().nodes().getMinNodeVersion(), ActionListener.wrap(
+                        this::validate, ActionListener.wrap(
                                 updatedJob -> postJobUpdate(request, updatedJob, actionListener),
                                 actionListener::onFailure
                         ));
@@ -603,7 +603,7 @@ public class JobManager {
             .setModelSnapshotId(modelSnapshot.getSnapshotId())
             .build();
 
-        jobConfigProvider.updateJob(request.getJobId(), update, maxModelMemoryLimit, clusterService.state().nodes().getMinNodeVersion(),
+        jobConfigProvider.updateJob(request.getJobId(), update, maxModelMemoryLimit,
             ActionListener.wrap(job -> {
                 auditor.info(request.getJobId(),
                     Messages.getMessage(Messages.JOB_AUDIT_REVERTED, modelSnapshot.getDescription()));

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobConfigProvider.java

@@ -10,7 +10,6 @@ import org.apache.logging.log4j.Logger;
 import org.apache.lucene.search.join.ScoreMode;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.DocWriteRequest;
 import org.elasticsearch.action.DocWriteResponse;
@@ -227,11 +226,9 @@ public class JobConfigProvider {
      * @param maxModelMemoryLimit The maximum model memory allowed. This can be {@code null}
      *                            if the job's {@link org.elasticsearch.xpack.core.ml.job.config.AnalysisLimits}
      *                            are not changed.
-     * @param minClusterNodeVersion the minimum version of nodes in the cluster
      * @param updatedJobListener Updated job listener
      */
     public void updateJob(String jobId, JobUpdate update, ByteSizeValue maxModelMemoryLimit,
-                          Version minClusterNodeVersion,
                           ActionListener<Job> updatedJobListener) {
         GetRequest getRequest = new GetRequest(AnomalyDetectorsIndex.configIndexName(),
                 ElasticsearchMappings.DOC_TYPE, Job.documentId(jobId));
@@ -266,7 +263,7 @@ public class JobConfigProvider {
                     return;
                 }
 
-                indexUpdatedJob(updatedJob, version, seqNo, primaryTerm, minClusterNodeVersion, updatedJobListener);
+                indexUpdatedJob(updatedJob, seqNo, primaryTerm, updatedJobListener);
             }
 
             @Override
@@ -287,18 +284,17 @@ public class JobConfigProvider {
     }
 
     /**
-     * Similar to {@link #updateJob(String, JobUpdate, ByteSizeValue, Version, ActionListener)} but
+     * Similar to {@link #updateJob(String, JobUpdate, ByteSizeValue, ActionListener)} but
      * with an extra validation step which is called before the updated is applied.
      *
      * @param jobId The Id of the job to update
      * @param update The job update
      * @param maxModelMemoryLimit The maximum model memory allowed
      * @param validator The job update validator
-     * @param minClusterNodeVersion the minimum version of a node ifn the cluster
      * @param updatedJobListener Updated job listener
      */
     public void updateJobWithValidation(String jobId, JobUpdate update, ByteSizeValue maxModelMemoryLimit,
-                                        UpdateValidator validator, Version minClusterNodeVersion, ActionListener<Job> updatedJobListener) {
+                                        UpdateValidator validator, ActionListener<Job> updatedJobListener) {
         GetRequest getRequest = new GetRequest(AnomalyDetectorsIndex.configIndexName(),
                 ElasticsearchMappings.DOC_TYPE, Job.documentId(jobId));
 
@@ -334,7 +330,7 @@ public class JobConfigProvider {
                                 return;
                             }
 
-                            indexUpdatedJob(updatedJob, version, seqNo, primaryTerm, minClusterNodeVersion, updatedJobListener);
+                            indexUpdatedJob(updatedJob, seqNo, primaryTerm, updatedJobListener);
                         },
                         updatedJobListener::onFailure
                 ));
@@ -347,7 +343,7 @@ public class JobConfigProvider {
         });
     }
 
-    private void indexUpdatedJob(Job updatedJob, long version, long seqNo, long primaryTerm, Version minClusterNodeVersion,
+    private void indexUpdatedJob(Job updatedJob, long seqNo, long primaryTerm,
                                  ActionListener<Job> updatedJobListener) {
         try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
             XContentBuilder updatedSource = updatedJob.toXContent(builder, ToXContent.EMPTY_PARAMS);
@@ -355,12 +351,8 @@ public class JobConfigProvider {
                     ElasticsearchMappings.DOC_TYPE, Job.documentId(updatedJob.getId()))
                     .setSource(updatedSource)
                     .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE);
-            if (minClusterNodeVersion.onOrAfter(Version.V_6_7_0)) {
-                indexRequest.setIfSeqNo(seqNo);
-                indexRequest.setIfPrimaryTerm(primaryTerm);
-            } else {
-                indexRequest.setVersion(version);
-            }
+            indexRequest.setIfSeqNo(seqNo);
+            indexRequest.setIfPrimaryTerm(primaryTerm);
 
             executeAsyncWithOrigin(client, ML_ORIGIN, IndexAction.INSTANCE, indexRequest.request(), ActionListener.wrap(
                     indexResponse -> {

x-pack/plugin/ml/src/test/java/org/elasticsearch/xpack/ml/integration/DatafeedConfigProviderIT.java

@@ -7,7 +7,6 @@ package org.elasticsearch.xpack.ml.integration;
 
 import org.elasticsearch.ResourceAlreadyExistsException;
 import org.elasticsearch.ResourceNotFoundException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.DocWriteResponse;
 import org.elasticsearch.action.delete.DeleteResponse;
@@ -87,7 +86,7 @@ public class DatafeedConfigProviderIT extends MlSingleNodeTestCase {
         AtomicReference<DatafeedConfig> configHolder = new AtomicReference<>();
         blockingCall(actionListener ->
                         datafeedConfigProvider.updateDatefeedConfig(datafeedId, update.build(), updateHeaders,
-                                (updatedConfig, listener) -> listener.onResponse(Boolean.TRUE), Version.CURRENT, actionListener),
+                                (updatedConfig, listener) -> listener.onResponse(Boolean.TRUE), actionListener),
                 configHolder, exceptionHolder);
         assertNull(exceptionHolder.get());
         assertThat(configHolder.get().getIndices(), equalTo(updateIndices));
@@ -168,7 +167,7 @@ public class DatafeedConfigProviderIT extends MlSingleNodeTestCase {
         AtomicReference<DatafeedConfig> configHolder = new AtomicReference<>();
         blockingCall(actionListener ->
                         datafeedConfigProvider.updateDatefeedConfig(datafeedId, update.build(), Collections.emptyMap(),
-                                (updatedConfig, listener) -> listener.onResponse(Boolean.TRUE), Version.CURRENT, actionListener),
+                                (updatedConfig, listener) -> listener.onResponse(Boolean.TRUE), actionListener),
                 configHolder, exceptionHolder);
         assertNull(configHolder.get());
         assertNotNull(exceptionHolder.get());
@@ -194,7 +193,7 @@ public class DatafeedConfigProviderIT extends MlSingleNodeTestCase {
         AtomicReference<Exception> exceptionHolder = new AtomicReference<>();
         blockingCall(actionListener ->
                         datafeedConfigProvider.updateDatefeedConfig(datafeedId, update.build(), Collections.emptyMap(),
-                                validateErrorFunction, Version.CURRENT, actionListener),
+                                validateErrorFunction, actionListener),
                 configHolder, exceptionHolder);
 
         assertNull(configHolder.get());

x-pack/plugin/ml/src/test/java/org/elasticsearch/xpack/ml/integration/JobConfigProviderIT.java

@@ -8,7 +8,6 @@ package org.elasticsearch.xpack.ml.integration;
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.ResourceAlreadyExistsException;
 import org.elasticsearch.ResourceNotFoundException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.DocWriteResponse;
 import org.elasticsearch.action.delete.DeleteResponse;
 import org.elasticsearch.action.index.IndexResponse;
@@ -149,7 +148,7 @@ public class JobConfigProviderIT extends MlSingleNodeTestCase {
 
         AtomicReference<Job> updateJobResponseHolder = new AtomicReference<>();
         blockingCall(actionListener -> jobConfigProvider.updateJob
-                (jobId, jobUpdate, new ByteSizeValue(32), Version.CURRENT, actionListener), updateJobResponseHolder, exceptionHolder);
+                (jobId, jobUpdate, new ByteSizeValue(32), actionListener), updateJobResponseHolder, exceptionHolder);
         assertNull(exceptionHolder.get());
         assertEquals("This job has been updated", updateJobResponseHolder.get().getDescription());
 
@@ -206,7 +205,7 @@ public class JobConfigProviderIT extends MlSingleNodeTestCase {
                 .build();
 
         AtomicReference<Job> updateJobResponseHolder = new AtomicReference<>();
-        blockingCall(actionListener -> jobConfigProvider.updateJob(jobId, invalidUpdate, new ByteSizeValue(32), Version.CURRENT,
+        blockingCall(actionListener -> jobConfigProvider.updateJob(jobId, invalidUpdate, new ByteSizeValue(32),
             actionListener), updateJobResponseHolder, exceptionHolder);
         assertNull(updateJobResponseHolder.get());
         assertNotNull(exceptionHolder.get());
@@ -231,7 +230,7 @@ public class JobConfigProviderIT extends MlSingleNodeTestCase {
         AtomicReference<Job> updateJobResponseHolder = new AtomicReference<>();
         // update with the no-op validator
         blockingCall(actionListener -> jobConfigProvider.updateJobWithValidation(
-            jobId, jobUpdate, new ByteSizeValue(32), validator, Version.CURRENT, actionListener), updateJobResponseHolder, exceptionHolder);
+            jobId, jobUpdate, new ByteSizeValue(32), validator, actionListener), updateJobResponseHolder, exceptionHolder);
 
         assertNull(exceptionHolder.get());
         assertNotNull(updateJobResponseHolder.get());
@@ -244,7 +243,7 @@ public class JobConfigProviderIT extends MlSingleNodeTestCase {
         updateJobResponseHolder.set(null);
         // Update with a validator that errors
         blockingCall(actionListener -> jobConfigProvider.updateJobWithValidation(jobId, jobUpdate, new ByteSizeValue(32),
-                validatorWithAnError, Version.CURRENT, actionListener),
+                validatorWithAnError, actionListener),
                 updateJobResponseHolder, exceptionHolder);
 
         assertNull(updateJobResponseHolder.get());

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/TokenService.java

@@ -750,12 +750,8 @@ public final class TokenService {
                                     client.prepareUpdate(SecurityIndexManager.SECURITY_INDEX_NAME, TYPE, tokenDocId)
                                         .setDoc("refresh_token", Collections.singletonMap("refreshed", true))
                                         .setRefreshPolicy(RefreshPolicy.WAIT_UNTIL);
-                                if (clusterService.state().nodes().getMinNodeVersion().onOrAfter(Version.V_6_7_0)) {
-                                    updateRequest.setIfSeqNo(response.getSeqNo());
-                                    updateRequest.setIfPrimaryTerm(response.getPrimaryTerm());
-                                } else {
-                                    updateRequest.setVersion(response.getVersion());
-                                }
+                                updateRequest.setIfSeqNo(response.getSeqNo());
+                                updateRequest.setIfPrimaryTerm(response.getPrimaryTerm());
                                 executeAsyncWithOrigin(client.threadPool().getThreadContext(), SECURITY_ORIGIN, updateRequest.request(),
                                     ActionListener.<UpdateResponse>wrap(
                                         updateResponse -> createUserToken(authentication, userAuth, listener, metadata, true),

x-pack/plugin/src/test/resources/rest-api-spec/test/watcher/put_watch/80_put_get_watch_with_passwords.yml

@@ -115,112 +115,6 @@ setup:
           }
 
 
----
-"Test putting a watch with a redacted password with old version returns an error":
-
-  # version 1
-  - do:
-      xpack.watcher.put_watch:
-        id: "watch_old_version"
-        body:  >
-          {
-            "trigger": {
-              "schedule" : { "cron" : "0 0 0 1 * ? 2099" }
-            },
-            "input": {
-              "http" : {
-                "request" : {
-                  "host" : "host.domain",
-                  "port" : 9200,
-                  "path" : "/myservice",
-                  "auth" : {
-                    "basic" : {
-                      "username" : "user",
-                      "password" : "pass"
-                    }
-                  }
-                }
-              }
-            },
-            "actions": {
-              "logging": {
-                "logging": {
-                  "text": "Log me Amadeus!"
-                }
-              }
-            }
-          }
-
-  # version 2
-  - do:
-      xpack.watcher.put_watch:
-        id: "watch_old_version"
-        body:  >
-          {
-            "trigger": {
-              "schedule" : { "cron" : "0 0 0 1 * ? 2099" }
-            },
-            "input": {
-              "http" : {
-                "request" : {
-                  "host" : "host.domain",
-                  "port" : 9200,
-                  "path" : "/myservice",
-                  "auth" : {
-                    "basic" : {
-                      "username" : "user",
-                      "password" : "pass"
-                    }
-                  }
-                }
-              }
-            },
-            "actions": {
-              "logging": {
-                "logging": {
-                  "text": "Log me Amadeus!"
-                }
-              }
-            }
-          }
-
-
-  # using optimistic concurrency control, this one will loose
-  # as if two users in the watch UI tried to update the same watch
-  - do:
-      catch: conflict
-      xpack.watcher.put_watch:
-        id: "watch_old_version"
-        version: 1
-        body:  >
-          {
-            "trigger": {
-              "schedule" : { "cron" : "0 0 0 1 * ? 2099" }
-            },
-            "input": {
-              "http" : {
-                "request" : {
-                  "host" : "host.domain",
-                  "port" : 9200,
-                  "path" : "/myservice",
-                  "auth" : {
-                    "basic" : {
-                      "username" : "user",
-                      "password" : "::es_redacted::"
-                    }
-                  }
-                }
-              }
-            },
-            "actions": {
-              "logging": {
-                "logging": {
-                  "text": "Log me Amadeus!"
-                }
-              }
-            }
-          }
-
 ---
 "Test putting a watch with a redacted password with old seq no returns an error":
   - skip:
@@ -390,98 +284,3 @@ setup:
   - match: { hits.hits.0._source.input.http.request.auth.basic.username: "new_user" }
   - match: { hits.hits.0._source.input.http.request.auth.basic.password: "pass" }
 
----
-"Test putting a watch with a redacted password with current version works":
-
-  - do:
-      xpack.watcher.put_watch:
-        id: "my_watch_with_version"
-        body:  >
-          {
-            "trigger": {
-              "schedule" : { "cron" : "0 0 0 1 * ? 2099" }
-            },
-            "input": {
-              "http" : {
-                "request" : {
-                  "host" : "host.domain",
-                  "port" : 9200,
-                  "path" : "/myservice",
-                  "auth" : {
-                    "basic" : {
-                      "username" : "user",
-                      "password" : "pass"
-                    }
-                  }
-                }
-              }
-            },
-            "actions": {
-              "logging": {
-                "logging": {
-                  "text": "Log me Amadeus!"
-                }
-              }
-            }
-          }
-
-  - match: { _id: "my_watch_with_version" }
-  - match: { _version: 1 }
-
-  # this resembles the exact update from the UI and thus should work, no password change, any change in the watch
-  # but correct version provided
-  - do:
-      xpack.watcher.put_watch:
-        id: "my_watch_with_version"
-        version: 1
-        body:  >
-          {
-            "trigger": {
-              "schedule" : { "cron" : "0 0 0 1 * ? 2099" }
-            },
-            "input": {
-              "http" : {
-                "request" : {
-                  "host" : "host.domain",
-                  "port" : 9200,
-                  "path" : "/myservice",
-                  "auth" : {
-                    "basic" : {
-                      "username" : "user",
-                      "password" : "::es_redacted::"
-                    }
-                  }
-                }
-              }
-            },
-            "actions": {
-              "logging": {
-                "logging": {
-                  "text": "Log me Amadeus!"
-                }
-              }
-            }
-          }
-
-  - match: { _id: "my_watch_with_version" }
-  - match: { _version: 2 }
-
-  - do:
-      search:
-        rest_total_hits_as_int: true
-        index: .watches
-        body:  >
-          {
-            "query": {
-              "term": {
-                "_id": {
-                  "value": "my_watch_with_version"
-                }
-              }
-            }
-          }
-
-  - match: { hits.total: 1 }
-  - match: { hits.hits.0._id: "my_watch_with_version" }
-  - match: { hits.hits.0._source.input.http.request.auth.basic.password: "pass" }
-