LLREST: Drop deprecated methods (#33223)

In #29623 we added `Request` object flavored requests to the low level
REST client and in #30315 we deprecated the old `performRequest`s. In a
long series of PRs I've changed all of the old style requests. This
drops the deprecated methods and will be released with 7.0.

client/rest/src/main/java/org/elasticsearch/client/RestClient.java

@@ -85,7 +85,7 @@ import static java.util.Collections.singletonList;
  * The hosts that are part of the cluster need to be provided at creation time, but can also be replaced later
  * by calling {@link #setNodes(Collection)}.
  * <p>
- * The method {@link #performRequest(String, String, Map, HttpEntity, Header...)} allows to send a request to the cluster. When
+ * The method {@link #performRequest(Request)} allows to send a request to the cluster. When
  * sending a request, a host gets selected out of the provided ones in a round-robin fashion. Failing hosts are marked dead and
  * retried after a certain amount of time (minimum 1 minute, maximum 30 minutes), depending on how many times they previously
  * failed (the more failures, the later they will be retried). In case of failures all of the alive nodes (or dead nodes that
@@ -145,17 +145,6 @@ public class RestClient implements Closeable {
         return new RestClientBuilder(hostsToNodes(hosts));
     }
 
-    /**
-     * Replaces the hosts with which the client communicates.
-     *
-     * @deprecated prefer {@link #setNodes(Collection)} because it allows you
-     * to set metadata for use with {@link NodeSelector}s
-     */
-    @Deprecated
-    public void setHosts(HttpHost... hosts) {
-        setNodes(hostsToNodes(hosts));
-    }
-
     /**
      * Replaces the nodes with which the client communicates.
      */
@@ -251,234 +240,6 @@ public class RestClient implements Closeable {
         }
     }
 
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to and waits for the corresponding response
-     * to be returned. Shortcut to {@link #performRequest(String, String, Map, HttpEntity, Header...)} but without parameters
-     * and request body.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param headers the optional request headers
-     * @return the response returned by Elasticsearch
-     * @throws IOException in case of a problem or the connection was aborted
-     * @throws ClientProtocolException in case of an http protocol error
-     * @throws ResponseException in case Elasticsearch responded with a status code that indicated an error
-     * @deprecated prefer {@link #performRequest(Request)}
-     */
-    @Deprecated
-    public Response performRequest(String method, String endpoint, Header... headers) throws IOException {
-        Request request = new Request(method, endpoint);
-        addHeaders(request, headers);
-        return performRequest(request);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to and waits for the corresponding response
-     * to be returned. Shortcut to {@link #performRequest(String, String, Map, HttpEntity, Header...)} but without request body.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param params the query_string parameters
-     * @param headers the optional request headers
-     * @return the response returned by Elasticsearch
-     * @throws IOException in case of a problem or the connection was aborted
-     * @throws ClientProtocolException in case of an http protocol error
-     * @throws ResponseException in case Elasticsearch responded with a status code that indicated an error
-     * @deprecated prefer {@link #performRequest(Request)}
-     */
-    @Deprecated
-    public Response performRequest(String method, String endpoint, Map<String, String> params, Header... headers) throws IOException {
-        Request request = new Request(method, endpoint);
-        addParameters(request, params);
-        addHeaders(request, headers);
-        return performRequest(request);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to and waits for the corresponding response
-     * to be returned. Shortcut to {@link #performRequest(String, String, Map, HttpEntity, HttpAsyncResponseConsumerFactory, Header...)}
-     * which doesn't require specifying an {@link HttpAsyncResponseConsumerFactory} instance,
-     * {@link HttpAsyncResponseConsumerFactory} will be used to create the needed instances of {@link HttpAsyncResponseConsumer}.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param params the query_string parameters
-     * @param entity the body of the request, null if not applicable
-     * @param headers the optional request headers
-     * @return the response returned by Elasticsearch
-     * @throws IOException in case of a problem or the connection was aborted
-     * @throws ClientProtocolException in case of an http protocol error
-     * @throws ResponseException in case Elasticsearch responded with a status code that indicated an error
-     * @deprecated prefer {@link #performRequest(Request)}
-     */
-    @Deprecated
-    public Response performRequest(String method, String endpoint, Map<String, String> params,
-                                   HttpEntity entity, Header... headers) throws IOException {
-        Request request = new Request(method, endpoint);
-        addParameters(request, params);
-        request.setEntity(entity);
-        addHeaders(request, headers);
-        return performRequest(request);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to. Blocks until the request is completed and returns
-     * its response or fails by throwing an exception. Selects a host out of the provided ones in a round-robin fashion. Failing hosts
-     * are marked dead and retried after a certain amount of time (minimum 1 minute, maximum 30 minutes), depending on how many times
-     * they previously failed (the more failures, the later they will be retried). In case of failures all of the alive nodes (or dead
-     * nodes that deserve a retry) are retried until one responds or none of them does, in which case an {@link IOException} will be thrown.
-     *
-     * This method works by performing an asynchronous call and waiting
-     * for the result. If the asynchronous call throws an exception we wrap
-     * it and rethrow it so that the stack trace attached to the exception
-     * contains the call site. While we attempt to preserve the original
-     * exception this isn't always possible and likely haven't covered all of
-     * the cases. You can get the original exception from
-     * {@link Exception#getCause()}.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param params the query_string parameters
-     * @param entity the body of the request, null if not applicable
-     * @param httpAsyncResponseConsumerFactory the {@link HttpAsyncResponseConsumerFactory} used to create one
-     * {@link HttpAsyncResponseConsumer} callback per retry. Controls how the response body gets streamed from a non-blocking HTTP
-     * connection on the client side.
-     * @param headers the optional request headers
-     * @return the response returned by Elasticsearch
-     * @throws IOException in case of a problem or the connection was aborted
-     * @throws ClientProtocolException in case of an http protocol error
-     * @throws ResponseException in case Elasticsearch responded with a status code that indicated an error
-     * @deprecated prefer {@link #performRequest(Request)}
-     */
-    @Deprecated
-    public Response performRequest(String method, String endpoint, Map<String, String> params,
-                                   HttpEntity entity, HttpAsyncResponseConsumerFactory httpAsyncResponseConsumerFactory,
-                                   Header... headers) throws IOException {
-        Request request = new Request(method, endpoint);
-        addParameters(request, params);
-        request.setEntity(entity);
-        setOptions(request, httpAsyncResponseConsumerFactory, headers);
-        return performRequest(request);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to. Doesn't wait for the response, instead
-     * the provided {@link ResponseListener} will be notified upon completion or failure. Shortcut to
-     * {@link #performRequestAsync(String, String, Map, HttpEntity, ResponseListener, Header...)} but without parameters and  request body.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param responseListener the {@link ResponseListener} to notify when the request is completed or fails
-     * @param headers the optional request headers
-     * @deprecated prefer {@link #performRequestAsync(Request, ResponseListener)}
-     */
-    @Deprecated
-    public void performRequestAsync(String method, String endpoint, ResponseListener responseListener, Header... headers) {
-        Request request;
-        try {
-            request = new Request(method, endpoint);
-            addHeaders(request, headers);
-        } catch (Exception e) {
-            responseListener.onFailure(e);
-            return;
-        }
-        performRequestAsync(request, responseListener);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to. Doesn't wait for the response, instead
-     * the provided {@link ResponseListener} will be notified upon completion or failure. Shortcut to
-     * {@link #performRequestAsync(String, String, Map, HttpEntity, ResponseListener, Header...)} but without request body.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param params the query_string parameters
-     * @param responseListener the {@link ResponseListener} to notify when the request is completed or fails
-     * @param headers the optional request headers
-     * @deprecated prefer {@link #performRequestAsync(Request, ResponseListener)}
-     */
-    @Deprecated
-    public void performRequestAsync(String method, String endpoint, Map<String, String> params,
-                                    ResponseListener responseListener, Header... headers) {
-        Request request;
-        try {
-            request = new Request(method, endpoint);
-            addParameters(request, params);
-            addHeaders(request, headers);
-        } catch (Exception e) {
-            responseListener.onFailure(e);
-            return;
-        }
-        performRequestAsync(request, responseListener);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to. Doesn't wait for the response, instead
-     * the provided {@link ResponseListener} will be notified upon completion or failure.
-     * Shortcut to {@link #performRequestAsync(String, String, Map, HttpEntity, HttpAsyncResponseConsumerFactory, ResponseListener,
-     * Header...)} which doesn't require specifying an {@link HttpAsyncResponseConsumerFactory} instance,
-     * {@link HttpAsyncResponseConsumerFactory} will be used to create the needed instances of {@link HttpAsyncResponseConsumer}.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param params the query_string parameters
-     * @param entity the body of the request, null if not applicable
-     * @param responseListener the {@link ResponseListener} to notify when the request is completed or fails
-     * @param headers the optional request headers
-     * @deprecated prefer {@link #performRequestAsync(Request, ResponseListener)}
-     */
-    @Deprecated
-    public void performRequestAsync(String method, String endpoint, Map<String, String> params,
-                                    HttpEntity entity, ResponseListener responseListener, Header... headers) {
-        Request request;
-        try {
-            request = new Request(method, endpoint);
-            addParameters(request, params);
-            request.setEntity(entity);
-            addHeaders(request, headers);
-        } catch (Exception e) {
-            responseListener.onFailure(e);
-            return;
-        }
-        performRequestAsync(request, responseListener);
-    }
-
-    /**
-     * Sends a request to the Elasticsearch cluster that the client points to. The request is executed asynchronously
-     * and the provided {@link ResponseListener} gets notified upon request completion or failure.
-     * Selects a host out of the provided ones in a round-robin fashion. Failing hosts are marked dead and retried after a certain
-     * amount of time (minimum 1 minute, maximum 30 minutes), depending on how many times they previously failed (the more failures,
-     * the later they will be retried). In case of failures all of the alive nodes (or dead nodes that deserve a retry) are retried
-     * until one responds or none of them does, in which case an {@link IOException} will be thrown.
-     *
-     * @param method the http method
-     * @param endpoint the path of the request (without host and port)
-     * @param params the query_string parameters
-     * @param entity the body of the request, null if not applicable
-     * @param httpAsyncResponseConsumerFactory the {@link HttpAsyncResponseConsumerFactory} used to create one
-     * {@link HttpAsyncResponseConsumer} callback per retry. Controls how the response body gets streamed from a non-blocking HTTP
-     * connection on the client side.
-     * @param responseListener the {@link ResponseListener} to notify when the request is completed or fails
-     * @param headers the optional request headers
-     * @deprecated prefer {@link #performRequestAsync(Request, ResponseListener)}
-     */
-    @Deprecated
-    public void performRequestAsync(String method, String endpoint, Map<String, String> params,
-                                    HttpEntity entity, HttpAsyncResponseConsumerFactory httpAsyncResponseConsumerFactory,
-                                    ResponseListener responseListener, Header... headers) {
-        Request request;
-        try {
-            request = new Request(method, endpoint);
-            addParameters(request, params);
-            request.setEntity(entity);
-            setOptions(request, httpAsyncResponseConsumerFactory, headers);
-        } catch (Exception e) {
-            responseListener.onFailure(e);
-            return;
-        }
-        performRequestAsync(request, responseListener);
-    }
-
     void performRequestAsyncNoCatch(Request request, ResponseListener listener) throws IOException {
         Map<String, String> requestParams = new HashMap<>(request.getParameters());
         //ignore is a special parameter supported by the clients, shouldn't be sent to es
@@ -1035,42 +796,4 @@ public class RestClient implements Closeable {
             itr.remove();
         }
     }
-
-    /**
-     * Add all headers from the provided varargs argument to a {@link Request}. This only exists
-     * to support methods that exist for backwards compatibility.
-     */
-    @Deprecated
-    private static void addHeaders(Request request, Header... headers) {
-        setOptions(request, RequestOptions.DEFAULT.getHttpAsyncResponseConsumerFactory(), headers);
-    }
-
-    /**
-     * Add all headers from the provided varargs argument to a {@link Request}. This only exists
-     * to support methods that exist for backwards compatibility.
-     */
-    @Deprecated
-    private static void setOptions(Request request, HttpAsyncResponseConsumerFactory httpAsyncResponseConsumerFactory,
-            Header... headers) {
-        Objects.requireNonNull(headers, "headers cannot be null");
-        RequestOptions.Builder options = request.getOptions().toBuilder();
-        for (Header header : headers) {
-            Objects.requireNonNull(header, "header cannot be null");
-            options.addHeader(header.getName(), header.getValue());
-        }
-        options.setHttpAsyncResponseConsumerFactory(httpAsyncResponseConsumerFactory);
-        request.setOptions(options);
-    }
-
-    /**
-     * Add all parameters from a map to a {@link Request}. This only exists
-     * to support methods that exist for backwards compatibility.
-     */
-    @Deprecated
-    private static void addParameters(Request request, Map<String, String> parameters) {
-        Objects.requireNonNull(parameters, "parameters cannot be null");
-        for (Map.Entry<String, String> entry : parameters.entrySet()) {
-            request.addParameter(entry.getKey(), entry.getValue());
-        }
-    }
 }

client/rest/src/test/java/org/elasticsearch/client/RestClientSingleHostIntegTests.java

@@ -45,7 +45,6 @@ import java.io.OutputStream;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -215,9 +214,15 @@ public class RestClientSingleHostIntegTests extends RestClientTestCase {
             }
             final Header[] requestHeaders = RestClientTestUtil.randomHeaders(getRandom(), "Header");
             final int statusCode = randomStatusCode(getRandom());
+            Request request = new Request(method, "/" + statusCode);
+            RequestOptions.Builder options = request.getOptions().toBuilder();
+            for (Header header : requestHeaders) {
+                options.addHeader(header.getName(), header.getValue());
+            }
+            request.setOptions(options);
             Response esResponse;
             try {
-                esResponse = restClient.performRequest(method, "/" + statusCode, Collections.<String, String>emptyMap(), requestHeaders);
+                esResponse = restClient.performRequest(request);
             } catch (ResponseException e) {
                 esResponse = e.getResponse();
             }

client/rest/src/test/java/org/elasticsearch/client/RestClientSingleHostTests.java

@@ -59,7 +59,6 @@ import java.net.URI;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -69,7 +68,6 @@ import static java.util.Collections.singletonList;
 import static org.elasticsearch.client.RestClientTestUtil.getAllErrorStatusCodes;
 import static org.elasticsearch.client.RestClientTestUtil.getHttpMethods;
 import static org.elasticsearch.client.RestClientTestUtil.getOkStatusCodes;
-import static org.elasticsearch.client.RestClientTestUtil.randomHttpMethod;
 import static org.elasticsearch.client.RestClientTestUtil.randomStatusCode;
 import static org.elasticsearch.client.SyncResponseListenerTests.assertExceptionStackContainsCallingMethod;
 import static org.hamcrest.CoreMatchers.equalTo;
@@ -192,7 +190,7 @@ public class RestClientSingleHostTests extends RestClientTestCase {
     public void testOkStatusCodes() throws IOException {
         for (String method : getHttpMethods()) {
             for (int okStatusCode : getOkStatusCodes()) {
-                Response response = performRequest(method, "/" + okStatusCode);
+                Response response = restClient.performRequest(new Request(method, "/" + okStatusCode));
                 assertThat(response.getStatusLine().getStatusCode(), equalTo(okStatusCode));
             }
         }
@@ -223,13 +221,11 @@ public class RestClientSingleHostTests extends RestClientTestCase {
             //error status codes should cause an exception to be thrown
             for (int errorStatusCode : getAllErrorStatusCodes()) {
                 try {
-                    Map<String, String> params;
-                    if (ignoreParam.isEmpty()) {
-                        params = Collections.emptyMap();
-                    } else {
-                        params = Collections.singletonMap("ignore", ignoreParam);
+                    Request request = new Request(method, "/" + errorStatusCode);
+                    if (false == ignoreParam.isEmpty()) {
+                        request.addParameter("ignore", ignoreParam);
                     }
-                    Response response = performRequest(method, "/" + errorStatusCode, params);
+                    Response response = restClient.performRequest(request);
                     if (expectedIgnores.contains(errorStatusCode)) {
                         //no exception gets thrown although we got an error status code, as it was configured to be ignored
                         assertEquals(errorStatusCode, response.getStatusLine().getStatusCode());
@@ -256,14 +252,14 @@ public class RestClientSingleHostTests extends RestClientTestCase {
         for (String method : getHttpMethods()) {
             //IOExceptions should be let bubble up
             try {
-                performRequest(method, "/coe");
+                restClient.performRequest(new Request(method, "/coe"));
                 fail("request should have failed");
             } catch(IOException e) {
                 assertThat(e, instanceOf(ConnectTimeoutException.class));
             }
             failureListener.assertCalled(singletonList(node));
             try {
-                performRequest(method, "/soe");
+                restClient.performRequest(new Request(method, "/soe"));
                 fail("request should have failed");
             } catch(IOException e) {
                 assertThat(e, instanceOf(SocketTimeoutException.class));
@@ -313,48 +309,6 @@ public class RestClientSingleHostTests extends RestClientTestCase {
         }
     }
 
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests}.
-     */
-    @Deprecated
-    public void tesPerformRequestOldStyleNullHeaders() throws IOException {
-        String method = randomHttpMethod(getRandom());
-        int statusCode = randomStatusCode(getRandom());
-        try {
-            performRequest(method, "/" + statusCode, (Header[])null);
-            fail("request should have failed");
-        } catch(NullPointerException e) {
-            assertEquals("request headers must not be null", e.getMessage());
-        }
-        try {
-            performRequest(method, "/" + statusCode, (Header)null);
-            fail("request should have failed");
-        } catch(NullPointerException e) {
-            assertEquals("request header must not be null", e.getMessage());
-        }
-    }
-
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests#testAddParameters()}.
-     */
-    @Deprecated
-    public void testPerformRequestOldStyleWithNullParams() throws IOException {
-        String method = randomHttpMethod(getRandom());
-        int statusCode = randomStatusCode(getRandom());
-        try {
-            restClient.performRequest(method, "/" + statusCode, (Map<String, String>)null);
-            fail("request should have failed");
-        } catch(NullPointerException e) {
-            assertEquals("parameters cannot be null", e.getMessage());
-        }
-        try {
-            restClient.performRequest(method, "/" + statusCode, null, (HttpEntity)null);
-            fail("request should have failed");
-        } catch(NullPointerException e) {
-            assertEquals("parameters cannot be null", e.getMessage());
-        }
-    }
-
     /**
      * End to end test for request and response headers. Exercises the mock http client ability to send back
      * whatever headers it has received.
@@ -464,35 +418,4 @@ public class RestClientSingleHostTests extends RestClientTestCase {
         }
         return expectedRequest;
     }
-
-    /**
-     * @deprecated prefer {@link RestClient#performRequest(Request)}.
-     */
-    @Deprecated
-    private Response performRequest(String method, String endpoint, Header... headers) throws IOException {
-        return performRequest(method, endpoint, Collections.<String, String>emptyMap(), headers);
-    }
-
-    /**
-     * @deprecated prefer {@link RestClient#performRequest(Request)}.
-     */
-    @Deprecated
-    private Response performRequest(String method, String endpoint, Map<String, String> params, Header... headers) throws IOException {
-        int methodSelector;
-        if (params.isEmpty()) {
-            methodSelector = randomIntBetween(0, 2);
-        } else {
-            methodSelector = randomIntBetween(1, 2);
-        }
-        switch(methodSelector) {
-            case 0:
-                return restClient.performRequest(method, endpoint, headers);
-            case 1:
-                return restClient.performRequest(method, endpoint, params, headers);
-            case 2:
-                return restClient.performRequest(method, endpoint, params, (HttpEntity)null, headers);
-            default:
-                throw new UnsupportedOperationException();
-        }
-    }
 }

client/rest/src/test/java/org/elasticsearch/client/RestClientTests.java

@@ -42,7 +42,6 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static java.util.Collections.singletonList;
-import static org.elasticsearch.client.RestClientTestUtil.getHttpMethods;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
@@ -90,88 +89,6 @@ public class RestClientTests extends RestClientTestCase {
         }
     }
 
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link #testPerformAsyncWithUnsupportedMethod()}.
-     */
-    @Deprecated
-    public void testPerformAsyncOldStyleWithUnsupportedMethod() throws Exception {
-        final CountDownLatch latch = new CountDownLatch(1);
-        try (RestClient restClient = createRestClient()) {
-            restClient.performRequestAsync("unsupported", randomAsciiLettersOfLength(5), new ResponseListener() {
-                @Override
-                public void onSuccess(Response response) {
-                    throw new UnsupportedOperationException("onSuccess cannot be called when using a mocked http client");
-                }
-
-                @Override
-                public void onFailure(Exception exception) {
-                    try {
-                        assertThat(exception, instanceOf(UnsupportedOperationException.class));
-                        assertEquals("http method not supported: unsupported", exception.getMessage());
-                    } finally {
-                        latch.countDown();
-                    }
-                }
-            });
-            assertTrue("time out waiting for request to return", latch.await(1000, TimeUnit.MILLISECONDS));
-        }
-    }
-
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests#testAddParameters()}.
-     */
-    @Deprecated
-    public void testPerformOldStyleAsyncWithNullParams() throws Exception {
-        final CountDownLatch latch = new CountDownLatch(1);
-        try (RestClient restClient = createRestClient()) {
-            restClient.performRequestAsync(randomAsciiLettersOfLength(5), randomAsciiLettersOfLength(5), null, new ResponseListener() {
-                @Override
-                public void onSuccess(Response response) {
-                    throw new UnsupportedOperationException("onSuccess cannot be called when using a mocked http client");
-                }
-
-                @Override
-                public void onFailure(Exception exception) {
-                    try {
-                        assertThat(exception, instanceOf(NullPointerException.class));
-                        assertEquals("parameters cannot be null", exception.getMessage());
-                    } finally {
-                        latch.countDown();
-                    }
-                }
-            });
-            assertTrue("time out waiting for request to return", latch.await(1000, TimeUnit.MILLISECONDS));
-        }
-    }
-
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests}.
-     */
-    @Deprecated
-    public void testPerformOldStyleAsyncWithNullHeaders() throws Exception {
-        final CountDownLatch latch = new CountDownLatch(1);
-        try (RestClient restClient = createRestClient()) {
-            ResponseListener listener = new ResponseListener() {
-                @Override
-                public void onSuccess(Response response) {
-                    throw new UnsupportedOperationException("onSuccess cannot be called when using a mocked http client");
-                }
-
-                @Override
-                public void onFailure(Exception exception) {
-                    try {
-                        assertThat(exception, instanceOf(NullPointerException.class));
-                        assertEquals("header cannot be null", exception.getMessage());
-                    } finally {
-                        latch.countDown();
-                    }
-                }
-            };
-            restClient.performRequestAsync("GET", randomAsciiLettersOfLength(5), listener, (Header) null);
-            assertTrue("time out waiting for request to return", latch.await(1000, TimeUnit.MILLISECONDS));
-        }
-    }
-
     public void testPerformAsyncWithWrongEndpoint() throws Exception {
         final CountDownLatch latch = new CountDownLatch(1);
         try (RestClient restClient = createRestClient()) {
@@ -195,33 +112,6 @@ public class RestClientTests extends RestClientTestCase {
         }
     }
 
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link #testPerformAsyncWithWrongEndpoint()}.
-     */
-    @Deprecated
-    public void testPerformAsyncOldStyleWithWrongEndpoint() throws Exception {
-        final CountDownLatch latch = new CountDownLatch(1);
-        try (RestClient restClient = createRestClient()) {
-            restClient.performRequestAsync("GET", "::http:///", new ResponseListener() {
-                @Override
-                public void onSuccess(Response response) {
-                    throw new UnsupportedOperationException("onSuccess cannot be called when using a mocked http client");
-                }
-
-                @Override
-                public void onFailure(Exception exception) {
-                    try {
-                        assertThat(exception, instanceOf(IllegalArgumentException.class));
-                        assertEquals("Expected scheme name at index 0: ::http:///", exception.getMessage());
-                    } finally {
-                        latch.countDown();
-                    }
-                }
-            });
-            assertTrue("time out waiting for request to return", latch.await(1000, TimeUnit.MILLISECONDS));
-        }
-    }
-
     public void testBuildUriLeavesPathUntouched() {
         final Map<String, String> emptyMap = Collections.emptyMap();
         {
@@ -259,34 +149,6 @@ public class RestClientTests extends RestClientTestCase {
         }
     }
 
-    @Deprecated
-    public void testSetHostsWrongArguments() throws IOException {
-        try (RestClient restClient = createRestClient()) {
-            restClient.setHosts((HttpHost[]) null);
-            fail("setHosts should have failed");
-        } catch (IllegalArgumentException e) {
-            assertEquals("hosts must not be null nor empty", e.getMessage());
-        }
-        try (RestClient restClient = createRestClient()) {
-            restClient.setHosts();
-            fail("setHosts should have failed");
-        } catch (IllegalArgumentException e) {
-            assertEquals("hosts must not be null nor empty", e.getMessage());
-        }
-        try (RestClient restClient = createRestClient()) {
-            restClient.setHosts((HttpHost) null);
-            fail("setHosts should have failed");
-        } catch (IllegalArgumentException e) {
-            assertEquals("host cannot be null", e.getMessage());
-        }
-        try (RestClient restClient = createRestClient()) {
-            restClient.setHosts(new HttpHost("localhost", 9200), null, new HttpHost("localhost", 9201));
-            fail("setHosts should have failed");
-        } catch (IllegalArgumentException e) {
-            assertEquals("host cannot be null", e.getMessage());
-        }
-    }
-
     public void testSetNodesWrongArguments() throws IOException {
         try (RestClient restClient = createRestClient()) {
             restClient.setNodes(null);
@@ -348,23 +210,6 @@ public class RestClientTests extends RestClientTestCase {
         }
     }
 
-    /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests#testConstructor()}.
-     */
-    @Deprecated
-    public void testNullPath() throws IOException {
-        try (RestClient restClient = createRestClient()) {
-            for (String method : getHttpMethods()) {
-                try {
-                    restClient.performRequest(method, null);
-                    fail("path set to null should fail!");
-                } catch (NullPointerException e) {
-                    assertEquals("endpoint cannot be null", e.getMessage());
-                }
-            }
-        }
-    }
-
     public void testSelectHosts() throws IOException {
         Node n1 = new Node(new HttpHost("1"), null, null, "1", null, null);
         Node n2 = new Node(new HttpHost("2"), null, null, "2", null, null);

docs/reference/migration/migrate_7_0.asciidoc

@@ -39,6 +39,7 @@ Elasticsearch 6.x in order to be readable by Elasticsearch 7.x.
 * <<breaking_70_scripting_changes>>
 * <<breaking_70_snapshotstats_changes>>
 * <<breaking_70_restclient_changes>>
+* <<breaking_70_low_level_restclient_changes>>
 
 include::migrate_7_0/aggregations.asciidoc[]
 include::migrate_7_0/analysis.asciidoc[]
@@ -53,4 +54,5 @@ include::migrate_7_0/java.asciidoc[]
 include::migrate_7_0/settings.asciidoc[]
 include::migrate_7_0/scripting.asciidoc[]
 include::migrate_7_0/snapshotstats.asciidoc[]
-include::migrate_7_0/restclient.asciidoc[]
+include::migrate_7_0/restclient.asciidoc[]
+include::migrate_7_0/low_level_restclient.asciidoc[]

docs/reference/migration/migrate_7_0/low_level_restclient.asciidoc

@@ -0,0 +1,14 @@
+[[breaking_70_low_level_restclient_changes]]
+=== Low-level REST client changes
+
+==== Deprecated flavors of performRequest have been removed
+
+We deprecated the flavors of `performRequest` and `performRequestAsync` that
+do not take `Request` objects in 6.4.0 in favor of the flavors that take
+`Request` objects because those methods can be extended without breaking
+backwards compatibility.
+
+==== Removed setHosts
+
+We deprecated `setHosts` in 6.4.0 in favor of `setNodes` because it supports
+host metadata used by the `NodeSelector`.