Merge branch 'master' into ccr

* master:
  Remove the index thread pool (#29556)
  Remove extra copy in ScriptDocValues.Strings
  Fix full cluster restart test recovery (#29545)
  Fix binary doc values fetching in _search (#29567)
  Mutes failing MovAvgIT tests
  Fix the assertion message for an incorrect current version. (#29572)
  Fix the version ID for v5.6.10. (#29570)
  Painless Spec Documentation Clean Up (#29441)
  Add versions 5.6.10 and 6.2.5
  [TEST] test against scaled value instead of fixed epsilon in MovAvgIT
  Remove `flatSettings` support from request classes (#29560)
  MapperService to wrap a single DocumentMapper. (#29511)
  Fix dependency checks on libs when generating Eclipse configuration. (#29550)
  Add null_value support to geo_point type (#29451)
  Add documentation about the include_type_name option. (#29555)
  Enforce translog access via engine (#29542)

Author: dnhatn

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

@@ -572,7 +572,6 @@ private static Request resize(ResizeRequest resizeRequest) throws IOException {
 
     static Request clusterPutSettings(ClusterUpdateSettingsRequest clusterUpdateSettingsRequest) throws IOException {
         Params parameters = Params.builder();
-        parameters.withFlatSettings(clusterUpdateSettingsRequest.flatSettings());
         parameters.withTimeout(clusterUpdateSettingsRequest.timeout());
         parameters.withMasterTimeout(clusterUpdateSettingsRequest.masterNodeTimeout());
         HttpEntity entity = createEntity(clusterUpdateSettingsRequest, REQUEST_BODY_CONTENT_TYPE);
@@ -603,7 +602,6 @@ static Request indicesExist(GetIndexRequest request) {
         params.withLocal(request.local());
         params.withHuman(request.humanReadable());
         params.withIndicesOptions(request.indicesOptions());
-        params.withFlatSettings(request.flatSettings());
         params.withIncludeDefaults(request.includeDefaults());
         return new Request(HttpHead.METHOD_NAME, endpoint, params.getParams(), null);
     }
@@ -613,7 +611,6 @@ static Request indexPutSettings(UpdateSettingsRequest updateSettingsRequest) thr
         parameters.withTimeout(updateSettingsRequest.timeout());
         parameters.withMasterTimeout(updateSettingsRequest.masterNodeTimeout());
         parameters.withIndicesOptions(updateSettingsRequest.indicesOptions());
-        parameters.withFlatSettings(updateSettingsRequest.flatSettings());
         parameters.withPreserveExisting(updateSettingsRequest.isPreserveExisting());
 
         String[] indices = updateSettingsRequest.indices() == null ? Strings.EMPTY_ARRAY : updateSettingsRequest.indices();

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

@@ -272,7 +272,6 @@ public void testIndicesExist() {
         Map<String, String> expectedParams = new HashMap<>();
         setRandomIndicesOptions(getIndexRequest::indicesOptions, getIndexRequest::indicesOptions, expectedParams);
         setRandomLocal(getIndexRequest, expectedParams);
-        setRandomFlatSettings(getIndexRequest::flatSettings, expectedParams);
         setRandomHumanReadable(getIndexRequest, expectedParams);
         setRandomIncludeDefaults(getIndexRequest, expectedParams);
 
@@ -1292,7 +1291,6 @@ private static void resizeTest(ResizeType resizeType, CheckedFunction<ResizeRequ
     public void testClusterPutSettings() throws IOException {
         ClusterUpdateSettingsRequest request = new ClusterUpdateSettingsRequest();
         Map<String, String> expectedParams = new HashMap<>();
-        setRandomFlatSettings(request::flatSettings, expectedParams);
         setRandomMasterTimeout(request, expectedParams);
         setRandomTimeout(request::timeout, AcknowledgedRequest.DEFAULT_ACK_TIMEOUT, expectedParams);
 
@@ -1344,7 +1342,6 @@ public void testIndexPutSettings() throws IOException {
         String[] indices = randomBoolean() ? null : randomIndicesNames(0, 2);
         UpdateSettingsRequest updateSettingsRequest = new UpdateSettingsRequest(indices);
         Map<String, String> expectedParams = new HashMap<>();
-        setRandomFlatSettings(updateSettingsRequest::flatSettings, expectedParams);
         setRandomMasterTimeout(updateSettingsRequest, expectedParams);
         setRandomTimeout(updateSettingsRequest::timeout, AcknowledgedRequest.DEFAULT_ACK_TIMEOUT, expectedParams);
         setRandomIndicesOptions(updateSettingsRequest::indicesOptions, updateSettingsRequest::indicesOptions, expectedParams);
@@ -1627,16 +1624,6 @@ private static void setRandomTimeout(Consumer<String> setter, TimeValue defaultT
         }
     }
 
-    private static void setRandomFlatSettings(Consumer<Boolean> setter, Map<String, String> expectedParams) {
-        if (randomBoolean()) {
-            boolean flatSettings = randomBoolean();
-            setter.accept(flatSettings);
-            if (flatSettings) {
-                expectedParams.put("flat_settings", String.valueOf(flatSettings));
-            }
-        }
-    }
-
     private static void setRandomMasterTimeout(MasterNodeRequest<?> request, Map<String, String> expectedParams) {
         if (randomBoolean()) {
             String masterTimeout = randomTimeValue();

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

@@ -124,10 +124,6 @@ public void testClusterPutSettings() throws IOException {
         request.masterNodeTimeout("1m"); // <2>
         // end::put-settings-request-masterTimeout
 
-        // tag::put-settings-request-flat-settings
-        request.flatSettings(true); // <1>
-        // end::put-settings-request-flat-settings
-
         // tag::put-settings-execute
         ClusterUpdateSettingsResponse response = client.cluster().putSettings(request);
         // end::put-settings-execute

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

@@ -58,7 +58,6 @@
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.client.ESRestHighLevelClientTestCase;
 import org.elasticsearch.client.RestHighLevelClient;
-import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.ByteSizeUnit;
 import org.elasticsearch.common.unit.ByteSizeValue;
@@ -114,8 +113,7 @@ public void testIndicesExist() throws IOException {
             request.local(false); // <1>
             request.humanReadable(true); // <2>
             request.includeDefaults(false); // <3>
-            request.flatSettings(false); // <4>
-            request.indicesOptions(indicesOptions); // <5>
+            request.indicesOptions(indicesOptions); // <4>
             // end::indices-exists-request-optionals
 
             // tag::indices-exists-response
@@ -1433,9 +1431,6 @@ public void testIndexPutSettings() throws Exception {
             // end::put-settings-settings-source
         }
 
-        // tag::put-settings-request-flat-settings
-        request.flatSettings(true); // <1>
-        // end::put-settings-request-flat-settings
         // tag::put-settings-request-preserveExisting
         request.setPreserveExisting(false); // <1>
         // end::put-settings-request-preserveExisting

docs/java-rest/high-level/cluster/put_settings.asciidoc

@@ -54,13 +54,6 @@ include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[put-settings-setti
 ==== Optional Arguments
 The following arguments can optionally be provided:
 
-["source","java",subs="attributes,callouts,macros"]
---------------------------------------------------
-include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[put-settings-request-flat-settings]
---------------------------------------------------
-<1> Whether the updated settings returned in the `ClusterUpdateSettings` should
-be in a flat format
-
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
 include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[put-settings-request-timeout]

docs/java-rest/high-level/indices/indices_exists.asciidoc

@@ -23,8 +23,7 @@ include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[indices-exists-req
 <1> Whether to return local information or retrieve the state from master node
 <2> Return result in a format suitable for humans
 <3> Whether to return all default setting for each of the indices
-<4> Return settings in flat format
-<5> Controls how unavailable indices are resolved and how wildcard expressions are expanded
+<4> Controls how unavailable indices are resolved and how wildcard expressions are expanded
 
 [[java-rest-high-indices-sync]]
 ==== Synchronous Execution

docs/java-rest/high-level/indices/put_settings.asciidoc

@@ -55,13 +55,6 @@ include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[put-settings-setti
 ==== Optional Arguments
 The following arguments can optionally be provided:
 
-["source","java",subs="attributes,callouts,macros"]
---------------------------------------------------
-include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[put-settings-request-flat-settings]
---------------------------------------------------
-<1> Whether the updated settings returned in the `UpdateSettings` should
-be in a flat format
-
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
 include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[put-settings-request-preserveExisting]

docs/painless/index.asciidoc

@@ -5,39 +5,6 @@ include::../Versions.asciidoc[]
 
 include::painless-getting-started.asciidoc[]
 
-// include::painless-examples.asciidoc[]
-
-// include::painless-design.asciidoc[]
-
 include::painless-lang-spec.asciidoc[]
 
-include::painless-syntax.asciidoc[]
-
 include::painless-api-reference.asciidoc[]
-
-////
-Proposed Outline (WIP)
-Getting Started with Painless
-  Accessing Doc Values
-  Updating Fields
-  Working with Dates
-  Using Regular Expressions
-  Debugging Painless Scripts
-
-Example Scripts
-  Using Painless in Script Fields
-  Using Painless in Watches
-  Using Painless in Function Score Queries
-  Using Painless in Script Queries
-  Using Painless When Updating Docs
-  Using Painless When Reindexing
-
-How Painless Works
-  Painless Architecture
-  Dispatching Functions
-
-Painless Language Specification
-Painless API
-////
-
-Painless API Reference

docs/painless/painless-api-reference.asciidoc

@@ -1,17 +1,13 @@
-["appendix",id="painless-api-reference"]
-= Painless API Reference
+[[painless-api-reference]]
+== Painless API Reference
 
-Painless has a strict whitelist for methods and
-classes to make sure that all painless scripts are secure and fast. Most of
-these methods are exposed directly from the JRE while others are part of
-Elasticsearch or Painless itself. Below is a list of all available methods
-grouped under the classes on which you can call them. Clicking on the method
-name takes you to the documentation for the method.
-
-NOTE: Methods defined in the JRE also have a `(java 9)` link which can be used
-to see the method's documentation in Java 9 while clicking on the method's name
-goes to the Java 8 documentation. Usually these aren't different but it is
-worth going to the version that matches the version of Java you are using to
-run Elasticsearch just in case.
+Painless has a strict whitelist for methods and classes to ensure all
+painless scripts are secure. Most of these methods are exposed directly
+from the Java Runtime Enviroment (JRE) while others are part of
+Elasticsearch or Painless itself. Below is a list of all available
+classes grouped with their respected methods. Clicking on the method
+name takes you to the documentation for that specific method.  Methods
+defined in the JRE also have a `(java 9)` link which can be used to see
+the method's documentation in Java 9.
 
 include::painless-api-reference/index.asciidoc[]

docs/painless/painless-casting.asciidoc

@@ -0,0 +1,172 @@
+[[painless-casting]]
+=== Casting
+
+Casting is the conversion of one type to another. Implicit casts are casts that
+occur automatically, such as during an assignment operation. Explicit casts are
+casts where you use the casting operator to explicitly convert one type to
+another. This is necessary during operations where the cast cannot be inferred.
+
+To cast to a new type, precede the expression by the new type enclosed in
+parentheses, for example
+`(int)x`.
+
+The following sections specify the implicit casts that can be performed and the
+explicit casts that are allowed. The only other permitted cast is casting
+a single character `String` to a `char`.
+
+*Grammar:*
+[source,ANTLR4]
+----
+cast: '(' TYPE ')' expression
+----
+
+[[numeric-casting]]
+==== Numeric Casting
+
+The following table shows the allowed implicit and explicit casts between
+numeric types. Read the table by row. To find out if you need to explicitly
+cast from type A to type B, find the row for type A and scan across to the
+column for type B.
+
+IMPORTANT: Explicit casts between numeric types can result in some data loss. A
+smaller numeric type cannot necessarily accommodate the value from a larger
+numeric type. You might also lose precision when casting from integer types
+to floating point types.
+
+|====
+|       | byte     | short    | char     | int      | long     | float    | double
+| byte  |          | implicit | implicit | implicit | implicit | implicit | implicit
+| short | explicit |          | explicit | implicit | implicit | implicit | implicit
+| char  | explicit | explicit |          | implicit | implicit | implicit | implicit
+| int   | explicit | explicit | explicit |          | implicit | implicit | implicit
+| long  | explicit | explicit | explicit | explicit |          | implicit | implicit
+| float | explicit | explicit | explicit | explicit | explicit |          | implicit
+| double | explicit | explicit | explicit | explicit | explicit | explicit |
+|====
+
+
+Example(s)
+[source,Java]
+----
+int a = 1;            // Declare int variable a and set it to the literal
+                      //   value 1
+long b = a;           // Declare long variable b and set it to int variable
+                      //    a with an implicit cast to convert from int to long
+short c = (short)b;   // Declare short variable c, explicitly cast b to a
+                      //   short, and assign b to c
+byte d = a;           // ERROR: Casting an int to a byte requires an explicit
+                      //   cast
+double e = (double)a; // Explicitly cast int variable a to a double and assign
+                      //   it to the double variable e. The explicit cast is
+                      //   allowed, but it is not necessary.
+----
+
+[[reference-casting]]
+==== Reference Casting
+
+A reference type can be implicitly cast to another reference type as long as
+the type being cast _from_ is a descendant of the type being cast _to_.  A
+reference type can be explicitly cast _to_ if the type being cast to is a
+descendant of the type being cast _from_.
+
+*Examples:*
+[source,Java]
+----
+List x;                        // Declare List variable x
+ArrayList y = new ArrayList(); // Declare ArrayList variable y and assign it a
+                               //   newly allocated ArrayList [1]
+x = y;                         // Assign Arraylist y to List x using an
+                               //   implicit cast
+y = (ArrayList)x;              // Explicitly cast List x to an ArrayList and
+                               //  assign it to ArrayList y
+x = (List)y;                   // Set List x to ArrayList y using an explicit
+                               //   cast (the explicit cast is not necessary)
+y = x;                         // ERROR: List x cannot be implicitly cast to
+                               //   an ArrayList, an explicit cast is required
+Map m = y;                     // ERROR: Cannot implicitly or explicitly cast [2]
+                               //   an ArrayList to a Map, no relationship
+                               //   exists between the two types.
+----
+[1] `ArrayList` is a descendant of the `List` type.
+[2] `Map` is unrelated to the `List` and `ArrayList` types.
+
+[[def-type-casting]]
+==== def Type Casting
+All primitive and reference types can always be implicitly cast to
+`def`. While it is possible to explicitly cast to `def`, it is not necessary.
+
+However, it is not always possible to implicitly cast a `def` to other
+primitive and reference types. An explicit cast is required if an explicit
+cast would normally be required between the non-def types.
+
+
+*Examples:*
+[source,Java]
+----
+def x;          // Declare def variable x and set it to null
+x = 3;          // Set the def variable x to the literal 3 with an implicit
+                //   cast from int to def
+double a = x;   // Declare double variable a and set it to def variable x,
+                //   which contains a double
+int b = x;      // ERROR: Results in a run-time error because an explicit cast is
+                //   required to cast from a double to an int
+int c = (int)x; // Declare int variable c, explicitly cast def variable x to an
+                //   int, and assign x to c
+----
+
+[[boxing-unboxing]]
+==== Boxing and Unboxing
+
+Boxing is where a cast is used to convert a primitive type to its corresponding
+reference type. Unboxing is the reverse, converting a reference type to the
+corresponding primitive type.
+
+There are two places Painless performs implicit boxing and unboxing:
+
+* When you call methods, Painless automatically boxes and unboxes arguments
+so you can specify either primitive types or their corresponding reference
+types.
+* When you use the `def` type, Painless automatically boxes and unboxes as
+needed when converting to and from `def`.
+
+The casting operator does not support any way to explicitly box a primitive
+type or unbox a reference type.
+
+If a primitive type needs to be converted to a reference type, the Painless
+reference type API supports methods that can do that. However, under normal
+circumstances this should not be necessary.
+
+*Examples:*
+[source,Java]
+----
+Integer x = 1;               // ERROR: not a legal implicit cast
+Integer y = (Integer)1;      // ERROR: not a legal explicit cast
+int a = new Integer(1);      // ERROR: not a legal implicit cast
+int b = (int)new Integer(1); // ERROR: not a legal explicit cast
+----
+
+[[promotion]]
+==== Promotion
+
+Promotion is where certain operations require types to be either a minimum
+numerical type or for two (or more) types to be equivalent.
+The documentation for each operation that has these requirements
+includes promotion tables that describe how this is handled.
+
+When an operation promotes a type or types, the resultant type
+of the operation is the promoted type.  Types can be promoted to def
+at compile-time; however, at run-time, the resultant type will be the
+promotion of the types the `def` is representing.
+
+*Examples:*
+[source,Java]
+----
+2 + 2.0     // Add the literal int 2 and the literal double 2.0. The literal
+            //   2 is promoted to a double and the resulting value is a double.
+
+def x = 1;  // Declare def variable x and set it to the literal int 1 through
+            //   an implicit cast
+x + 2.0F    // Add def variable x and the literal float 2.0.
+            // At compile-time the types are promoted to def.
+            // At run-time the types are promoted to float.
+----