From 24cf0619a9dce235d6555034efe4bc45341499ec Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Thu, 10 Mar 2022 16:36:15 -0800
Subject: [PATCH 01/13] Add request parameter cluster_manager_timeout

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../support/master/MasterNodeRequest.java     | 36 ++++++++++++++++++-
 .../java/org/opensearch/rest/RestRequest.java | 26 ++++++++++++++
 .../rest/action/cat/RestPluginsAction.java    |  3 ++
 3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java b/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java
index d5be6c48e23b8..55d5048f14d13 100644
--- a/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java
+++ b/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java
@@ -44,9 +44,15 @@
  */
 public abstract class MasterNodeRequest<Request extends MasterNodeRequest<Request>> extends ActionRequest {
 
+    /**
+     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #DEFAULT_CLUSTER_MANAGER_NODE_TIMEOUT}
+     */
+    @Deprecated
     public static final TimeValue DEFAULT_MASTER_NODE_TIMEOUT = TimeValue.timeValueSeconds(30);
 
-    protected TimeValue masterNodeTimeout = DEFAULT_MASTER_NODE_TIMEOUT;
+    public static final TimeValue DEFAULT_CLUSTER_MANAGER_NODE_TIMEOUT = TimeValue.timeValueSeconds(30);
+
+    protected TimeValue masterNodeTimeout = DEFAULT_CLUSTER_MANAGER_NODE_TIMEOUT;
 
     protected MasterNodeRequest() {}
 
@@ -63,21 +69,49 @@ public void writeTo(StreamOutput out) throws IOException {
 
     /**
      * A timeout value in case the master has not been discovered yet or disconnected.
+     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #clusterManagerNodeTimeout}
      */
+    @Deprecated
     @SuppressWarnings("unchecked")
     public final Request masterNodeTimeout(TimeValue timeout) {
         this.masterNodeTimeout = timeout;
         return (Request) this;
     }
 
+    /**
+     * A timeout value in case the cluster manager has not been discovered yet or disconnected.
+     */
+    @SuppressWarnings("unchecked")
+    public final Request clusterManagerNodeTimeout(TimeValue timeout) {
+        this.masterNodeTimeout = timeout;
+        return (Request) this;
+    }
+
     /**
      * A timeout value in case the master has not been discovered yet or disconnected.
+     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #clusterManagerNodeTimeout}
      */
+    @Deprecated
     public final Request masterNodeTimeout(String timeout) {
         return masterNodeTimeout(TimeValue.parseTimeValue(timeout, null, getClass().getSimpleName() + ".masterNodeTimeout"));
     }
 
+    /**
+     * A timeout value in case the cluster manager has not been discovered yet or disconnected.
+     */
+    public final Request clusterManagerNodeTimeout(String timeout) {
+        return clusterManagerNodeTimeout(TimeValue.parseTimeValue(timeout, null, getClass().getSimpleName() + ".masterNodeTimeout"));
+    }
+
+    /**
+     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #clusterManagerNodeTimeout}
+     */
+    @Deprecated
     public final TimeValue masterNodeTimeout() {
         return this.masterNodeTimeout;
     }
+
+    public final TimeValue clusterManagerNodeTimeout() {
+        return this.masterNodeTimeout;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/rest/RestRequest.java b/server/src/main/java/org/opensearch/rest/RestRequest.java
index 7d11da7e122cd..dabcea154ba1d 100644
--- a/server/src/main/java/org/opensearch/rest/RestRequest.java
+++ b/server/src/main/java/org/opensearch/rest/RestRequest.java
@@ -54,6 +54,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -578,6 +579,31 @@ public static XContentType parseContentType(List<String> header) {
         throw new IllegalArgumentException("empty Content-Type header");
     }
 
+    /**
+     * The method is only used to validate whether the values of the 2 request parameters "master_timeout" and "cluster_manager_timeout" is the same value or not.
+     * If the 2 values are not the same, throw an {@link OpenSearchParseException}.
+     * @param keys Keys of the request parameters.
+     * @deprecated The method will be removed along with the request parameter "master_timeout".
+     */
+    @Deprecated
+    public void validateParamValuesAreEqual(String... keys) {
+        // Filter the non-null values of the parameters with the key, and get the distinct values.
+        Set<String> set = new HashSet<>();
+        for (String key : keys) {
+            String value = param(key);
+            if (value != null) {
+                set.add(value);
+            }
+        }
+        // If there are more than 1 distinct value of the request parameters, throw an exception.
+        if (set.size() > 1) {
+            throw new OpenSearchParseException(
+                "The values of the request parameters: {} are required to be equal, otherwise please only assign value to one of the request parameters.",
+                Arrays.toString(keys)
+            );
+        }
+    }
+
     public static class ContentTypeHeaderException extends RuntimeException {
 
         ContentTypeHeaderException(final IllegalArgumentException cause) {
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
index 79cac0f906c74..5058967bc55dc 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
@@ -76,6 +76,9 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         clusterStateRequest.clear().nodes(true);
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
+        // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
+        request.validateParamValuesAreEqual("master_timeout", "cluster_manager_timeout");
+        clusterStateRequest.masterNodeTimeout(request.paramAsTime("cluster_manager_timeout", clusterStateRequest.masterNodeTimeout()));
 
         return channel -> client.admin().cluster().state(clusterStateRequest, new RestActionListener<ClusterStateResponse>(channel) {
             @Override

From 67d9e1bd9da587907c3d45da3cb36e7e6016aa9a Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Thu, 10 Mar 2022 23:03:59 -0800
Subject: [PATCH 02/13] Add deprecation notice to master_timeout

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../src/main/resources/rest-api-spec/api/cat.nodes.json   | 8 ++++++++
 .../org/opensearch/rest/action/cat/AbstractCatAction.java | 7 +++++++
 .../org/opensearch/rest/action/cat/RestNodesAction.java   | 6 ++++++
 .../org/opensearch/rest/action/cat/RestPluginsAction.java | 5 +++++
 4 files changed, 26 insertions(+)

diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json b/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json
index ba3faa92c5ec6..8edbe3c5ff634 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json
@@ -50,6 +50,14 @@
         }
       },
       "master_timeout":{
+        "type":"time",
+        "description":"Explicit operation timeout for connection to master node",
+        "deprecated":{
+          "version":"2.0.0",
+          "description":"To promote inclusive language, use 'cluster_manager_timeout' instead."
+        }
+      },
+      "cluster_manager_timeout":{
         "type":"time",
         "description":"Explicit operation timeout for connection to master node"
       },
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java b/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
index d82a32cfc2c5d..edd556c17b596 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
@@ -58,6 +58,13 @@ public abstract class AbstractCatAction extends BaseRestHandler {
 
     protected abstract Table getTableWithHeader(RestRequest request);
 
+    /**
+     * @deprecated It will be removed along with the request parameter "master_timeout".
+     */
+    @Deprecated
+    protected static final String DEPRECATED_MESSAGE_MASTER_TIMEOUT = "Deprecated parameter [master_timeout] used. To promote inclusive language, " +
+            "please use [cluster_manager_timeout] instead. It will be unsupported in a future major version.";
+
     @Override
     public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
         boolean helpWanted = request.paramAsBoolean("help", false);
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
index bce9b2d6b7e9d..453f31fab643a 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
@@ -111,6 +111,12 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         }
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
+        // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
+        if (request.hasParam("master_timeout")) {
+            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", DEPRECATED_MESSAGE_MASTER_TIMEOUT);
+        }
+        request.validateParamValuesAreEqual("master_timeout", "cluster_manager_timeout");
+        clusterStateRequest.masterNodeTimeout(request.paramAsTime("cluster_manager_timeout", clusterStateRequest.masterNodeTimeout()));
         final boolean fullId = request.paramAsBoolean("full_id", false);
         return channel -> client.admin().cluster().state(clusterStateRequest, new RestActionListener<ClusterStateResponse>(channel) {
             @Override
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
index 5058967bc55dc..971acdd7a5f88 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
@@ -42,6 +42,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.common.Table;
+import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.plugins.PluginInfo;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.RestResponse;
@@ -54,6 +55,7 @@
 import static org.opensearch.rest.RestRequest.Method.GET;
 
 public class RestPluginsAction extends AbstractCatAction {
+    private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(RestPluginsAction.class);
 
     @Override
     public List<Route> routes() {
@@ -77,6 +79,9 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
         // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
+        if (request.hasParam("master_timeout")) {
+            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", DEPRECATED_MESSAGE_MASTER_TIMEOUT);
+        }
         request.validateParamValuesAreEqual("master_timeout", "cluster_manager_timeout");
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("cluster_manager_timeout", clusterStateRequest.masterNodeTimeout()));
 

From 8da36a95bc10a261ccf6b85b60f383f3e808a432 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Sat, 12 Mar 2022 22:52:03 -0800
Subject: [PATCH 03/13] Revert deprecating methods in MasterNodeRequest

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../support/master/MasterNodeRequest.java     | 36 +------------------
 .../rest/action/cat/AbstractCatAction.java    |  9 ++---
 .../rest/action/cat/RestPluginsAction.java    |  1 +
 3 files changed, 5 insertions(+), 41 deletions(-)

diff --git a/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java b/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java
index 55d5048f14d13..d5be6c48e23b8 100644
--- a/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java
+++ b/server/src/main/java/org/opensearch/action/support/master/MasterNodeRequest.java
@@ -44,15 +44,9 @@
  */
 public abstract class MasterNodeRequest<Request extends MasterNodeRequest<Request>> extends ActionRequest {
 
-    /**
-     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #DEFAULT_CLUSTER_MANAGER_NODE_TIMEOUT}
-     */
-    @Deprecated
     public static final TimeValue DEFAULT_MASTER_NODE_TIMEOUT = TimeValue.timeValueSeconds(30);
 
-    public static final TimeValue DEFAULT_CLUSTER_MANAGER_NODE_TIMEOUT = TimeValue.timeValueSeconds(30);
-
-    protected TimeValue masterNodeTimeout = DEFAULT_CLUSTER_MANAGER_NODE_TIMEOUT;
+    protected TimeValue masterNodeTimeout = DEFAULT_MASTER_NODE_TIMEOUT;
 
     protected MasterNodeRequest() {}
 
@@ -69,49 +63,21 @@ public void writeTo(StreamOutput out) throws IOException {
 
     /**
      * A timeout value in case the master has not been discovered yet or disconnected.
-     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #clusterManagerNodeTimeout}
      */
-    @Deprecated
     @SuppressWarnings("unchecked")
     public final Request masterNodeTimeout(TimeValue timeout) {
         this.masterNodeTimeout = timeout;
         return (Request) this;
     }
 
-    /**
-     * A timeout value in case the cluster manager has not been discovered yet or disconnected.
-     */
-    @SuppressWarnings("unchecked")
-    public final Request clusterManagerNodeTimeout(TimeValue timeout) {
-        this.masterNodeTimeout = timeout;
-        return (Request) this;
-    }
-
     /**
      * A timeout value in case the master has not been discovered yet or disconnected.
-     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #clusterManagerNodeTimeout}
      */
-    @Deprecated
     public final Request masterNodeTimeout(String timeout) {
         return masterNodeTimeout(TimeValue.parseTimeValue(timeout, null, getClass().getSimpleName() + ".masterNodeTimeout"));
     }
 
-    /**
-     * A timeout value in case the cluster manager has not been discovered yet or disconnected.
-     */
-    public final Request clusterManagerNodeTimeout(String timeout) {
-        return clusterManagerNodeTimeout(TimeValue.parseTimeValue(timeout, null, getClass().getSimpleName() + ".masterNodeTimeout"));
-    }
-
-    /**
-     * @deprecated As of 2.0, because promoting inclusive language, replaced by {@link #clusterManagerNodeTimeout}
-     */
-    @Deprecated
     public final TimeValue masterNodeTimeout() {
         return this.masterNodeTimeout;
     }
-
-    public final TimeValue clusterManagerNodeTimeout() {
-        return this.masterNodeTimeout;
-    }
 }
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java b/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
index edd556c17b596..1deb58aab702a 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
@@ -58,12 +58,9 @@ public abstract class AbstractCatAction extends BaseRestHandler {
 
     protected abstract Table getTableWithHeader(RestRequest request);
 
-    /**
-     * @deprecated It will be removed along with the request parameter "master_timeout".
-     */
-    @Deprecated
-    protected static final String DEPRECATED_MESSAGE_MASTER_TIMEOUT = "Deprecated parameter [master_timeout] used. To promote inclusive language, " +
-            "please use [cluster_manager_timeout] instead. It will be unsupported in a future major version.";
+    // TODO: Remove this line after removing MASTER_ROLE. It's used for the REST CAT actions that accepts parameter 'master_timeout'
+    protected static final String DEPRECATED_MESSAGE_MASTER_TIMEOUT =
+        "Deprecated parameter [master_timeout] used. To promote inclusive language, please use [cluster_manager_timeout] instead. It will be unsupported in a future major version.";
 
     @Override
     public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
index 971acdd7a5f88..412496ce8b23a 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
@@ -79,6 +79,7 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
         // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
+        // TODO: 
         if (request.hasParam("master_timeout")) {
             deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", DEPRECATED_MESSAGE_MASTER_TIMEOUT);
         }

From 3f46f4ec680e690b1528f77c30cf35db6a0201ba Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Sat, 12 Mar 2022 22:54:39 -0800
Subject: [PATCH 04/13] Add todo to remove master_timeout

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../java/org/opensearch/rest/action/cat/RestNodesAction.java    | 1 +
 .../java/org/opensearch/rest/action/cat/RestPluginsAction.java  | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
index 453f31fab643a..d137c63e7224d 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
@@ -110,6 +110,7 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
             deprecationLogger.deprecate("cat_nodes_local_parameter", LOCAL_DEPRECATED_MESSAGE);
         }
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
+        // TODO: Remove below lines about 'master_timeout', after removing MASTER_ROLE.
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
         // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
         if (request.hasParam("master_timeout")) {
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
index 412496ce8b23a..a378c9ffa1ffd 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
@@ -77,9 +77,9 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         final ClusterStateRequest clusterStateRequest = new ClusterStateRequest();
         clusterStateRequest.clear().nodes(true);
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
+        // TODO: Remove below lines about 'master_timeout', after removing MASTER_ROLE.
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
         // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
-        // TODO: 
         if (request.hasParam("master_timeout")) {
             deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", DEPRECATED_MESSAGE_MASTER_TIMEOUT);
         }

From 8e0e0744252c87e6ad86f670dc2ecc03c98f6f35 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Mon, 14 Mar 2022 17:09:58 -0700
Subject: [PATCH 05/13] Add unit test for the temporary method
 ValidateParamValuesAreEqual()

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../org/opensearch/rest/RestRequestTests.java | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/server/src/test/java/org/opensearch/rest/RestRequestTests.java b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
index 7abc53e4ca610..99e6c7bf0ea70 100644
--- a/server/src/test/java/org/opensearch/rest/RestRequestTests.java
+++ b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
@@ -47,6 +47,7 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -280,6 +281,34 @@ public void testRequiredContent() {
         assertEquals("unknown content type", e.getMessage());
     }
 
+    /*
+     * The test is added in 2.0 when the request parameter "cluster_manager_timeout" is introduced.
+     * Remove the test along with the removal of the non-inclusive terminology "master_timeout".
+     */
+    public void testValidateParamValuesAreEqual() {
+        FakeRestRequest request = new FakeRestRequest();
+        List<String> valueList = new ArrayList<>(Arrays.asList(null, "value1", "value2"));
+        String valueForKey1 = randomFrom(valueList);
+        String valueForKey2 = randomFrom(valueList);
+        request.params().put("key1", valueForKey1);
+        request.params().put("key2", valueForKey2);
+        try {
+            request.validateParamValuesAreEqual("key1", "key2");
+        } catch (OpenSearchParseException e) {
+            assertEquals(
+                "The values of the request parameters: [key1, key2] are required to be equal, otherwise please only assign value to one of the request parameters.",
+                e.getMessage()
+            );
+            assertNotEquals(valueForKey1, valueForKey2);
+            assertNotNull(valueForKey1);
+            assertNotNull(valueForKey2);
+        }
+        assertTrue(
+            "The 2 keys should be either equal, or having null value.",
+            valueForKey1 == null || valueForKey2 == null || valueForKey1.equals(valueForKey2)
+        );
+    }
+
     private static RestRequest contentRestRequest(String content, Map<String, String> params) {
         Map<String, List<String>> headers = new HashMap<>();
         headers.put("Content-Type", Collections.singletonList("application/json"));

From dec2597ccb88422c5f9f17024c2ac7eb414c19f6 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Mon, 14 Mar 2022 18:08:15 -0700
Subject: [PATCH 06/13] Put codes of parsing master_timeout into a method

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../rest-api-spec/api/cat.nodes.json          |  2 +-
 .../rest/action/cat/AbstractCatAction.java    |  4 ---
 .../rest/action/cat/RestNodesAction.java      | 31 ++++++++++++++-----
 .../rest/action/cat/RestPluginsAction.java    |  9 ------
 4 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json b/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json
index 8edbe3c5ff634..abb13d015b4d5 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/cat.nodes.json
@@ -59,7 +59,7 @@
       },
       "cluster_manager_timeout":{
         "type":"time",
-        "description":"Explicit operation timeout for connection to master node"
+        "description":"Explicit operation timeout for connection to cluster-manager node"
       },
       "h":{
         "type":"list",
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java b/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
index 1deb58aab702a..d82a32cfc2c5d 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/AbstractCatAction.java
@@ -58,10 +58,6 @@ public abstract class AbstractCatAction extends BaseRestHandler {
 
     protected abstract Table getTableWithHeader(RestRequest request);
 
-    // TODO: Remove this line after removing MASTER_ROLE. It's used for the REST CAT actions that accepts parameter 'master_timeout'
-    protected static final String DEPRECATED_MESSAGE_MASTER_TIMEOUT =
-        "Deprecated parameter [master_timeout] used. To promote inclusive language, please use [cluster_manager_timeout] instead. It will be unsupported in a future major version.";
-
     @Override
     public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
         boolean helpWanted = request.paramAsBoolean("help", false);
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
index d137c63e7224d..07bf36e6eee80 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
@@ -110,14 +110,8 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
             deprecationLogger.deprecate("cat_nodes_local_parameter", LOCAL_DEPRECATED_MESSAGE);
         }
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
-        // TODO: Remove below lines about 'master_timeout', after removing MASTER_ROLE.
-        clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
-        // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
-        if (request.hasParam("master_timeout")) {
-            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", DEPRECATED_MESSAGE_MASTER_TIMEOUT);
-        }
-        request.validateParamValuesAreEqual("master_timeout", "cluster_manager_timeout");
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("cluster_manager_timeout", clusterStateRequest.masterNodeTimeout()));
+        parseDeprecatedMasterTimeoutParam(clusterStateRequest, request);
         final boolean fullId = request.paramAsBoolean("full_id", false);
         return channel -> client.admin().cluster().state(clusterStateRequest, new RestActionListener<ClusterStateResponse>(channel) {
             @Override
@@ -532,4 +526,27 @@ Table buildTable(
     private short calculatePercentage(long used, long max) {
         return max <= 0 ? 0 : (short) ((100d * used) / max);
     }
+
+    /**
+     * Parse the deprecated request parameter 'master_timeout', and add deprecated log if the parameter is used.
+     * It also validates whether the value of 'master_timeout' is the same with 'cluster_manager_timeout'.
+     * Remove the method along with MASTER_ROLE.
+     * @deprecated As of 2.0, because promoting inclusive language.
+     */
+    @Deprecated
+    private void parseDeprecatedMasterTimeoutParam(ClusterStateRequest clusterStateRequest, RestRequest request) {
+        final String deprecatedTimeoutParam = "master_timeout";
+        final String clusterManagerTimeoutParam = "cluster_manager_timeout";
+        final String deprecatedMessage = String.format(
+            Locale.US,
+            "Deprecated parameter [%s] used. To promote inclusive language, please use [%s] instead. It will be unsupported in a future major version.",
+            deprecatedTimeoutParam,
+            clusterManagerTimeoutParam
+        );
+        clusterStateRequest.masterNodeTimeout(request.paramAsTime(deprecatedTimeoutParam, clusterStateRequest.masterNodeTimeout()));
+        if (request.hasParam(deprecatedTimeoutParam)) {
+            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", deprecatedMessage);
+            request.validateParamValuesAreEqual(deprecatedTimeoutParam, clusterManagerTimeoutParam);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
index a378c9ffa1ffd..79cac0f906c74 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestPluginsAction.java
@@ -42,7 +42,6 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.common.Table;
-import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.plugins.PluginInfo;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.RestResponse;
@@ -55,7 +54,6 @@
 import static org.opensearch.rest.RestRequest.Method.GET;
 
 public class RestPluginsAction extends AbstractCatAction {
-    private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(RestPluginsAction.class);
 
     @Override
     public List<Route> routes() {
@@ -77,14 +75,7 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         final ClusterStateRequest clusterStateRequest = new ClusterStateRequest();
         clusterStateRequest.clear().nodes(true);
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
-        // TODO: Remove below lines about 'master_timeout', after removing MASTER_ROLE.
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));
-        // Add "cluster_manager_timeout" as the alternative to "master_timeout", for promoting inclusive language.
-        if (request.hasParam("master_timeout")) {
-            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", DEPRECATED_MESSAGE_MASTER_TIMEOUT);
-        }
-        request.validateParamValuesAreEqual("master_timeout", "cluster_manager_timeout");
-        clusterStateRequest.masterNodeTimeout(request.paramAsTime("cluster_manager_timeout", clusterStateRequest.masterNodeTimeout()));
 
         return channel -> client.admin().cluster().state(clusterStateRequest, new RestActionListener<ClusterStateResponse>(channel) {
             @Override

From 7bf815c4c1fd68a775e22b60e6a6796348f41fe8 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Mon, 14 Mar 2022 19:09:42 -0700
Subject: [PATCH 07/13] Use Strings.isNullorEmpty

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../main/java/org/opensearch/rest/RestRequest.java    |  4 ++--
 .../java/org/opensearch/rest/RestRequestTests.java    | 11 ++++++-----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/server/src/main/java/org/opensearch/rest/RestRequest.java b/server/src/main/java/org/opensearch/rest/RestRequest.java
index dabcea154ba1d..75b0723388793 100644
--- a/server/src/main/java/org/opensearch/rest/RestRequest.java
+++ b/server/src/main/java/org/opensearch/rest/RestRequest.java
@@ -587,11 +587,11 @@ public static XContentType parseContentType(List<String> header) {
      */
     @Deprecated
     public void validateParamValuesAreEqual(String... keys) {
-        // Filter the non-null values of the parameters with the key, and get the distinct values.
+        // Filter the non-empty values of the parameters with the key, and get the distinct values.
         Set<String> set = new HashSet<>();
         for (String key : keys) {
             String value = param(key);
-            if (value != null) {
+            if (!Strings.isNullOrEmpty(value)) {
                 set.add(value);
             }
         }
diff --git a/server/src/test/java/org/opensearch/rest/RestRequestTests.java b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
index 99e6c7bf0ea70..b50049f8e7d4b 100644
--- a/server/src/test/java/org/opensearch/rest/RestRequestTests.java
+++ b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.common.CheckedConsumer;
+import org.opensearch.common.Strings;
 import org.opensearch.common.bytes.BytesArray;
 import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.collect.MapBuilder;
@@ -287,7 +288,7 @@ public void testRequiredContent() {
      */
     public void testValidateParamValuesAreEqual() {
         FakeRestRequest request = new FakeRestRequest();
-        List<String> valueList = new ArrayList<>(Arrays.asList(null, "value1", "value2"));
+        List<String> valueList = new ArrayList<>(Arrays.asList(null, "", "value1", "value2"));
         String valueForKey1 = randomFrom(valueList);
         String valueForKey2 = randomFrom(valueList);
         request.params().put("key1", valueForKey1);
@@ -300,12 +301,12 @@ public void testValidateParamValuesAreEqual() {
                 e.getMessage()
             );
             assertNotEquals(valueForKey1, valueForKey2);
-            assertNotNull(valueForKey1);
-            assertNotNull(valueForKey2);
+            assertFalse(Strings.isNullOrEmpty(valueForKey1));
+            assertFalse(Strings.isNullOrEmpty(valueForKey2));
         }
         assertTrue(
-            "The 2 keys should be either equal, or having null value.",
-            valueForKey1 == null || valueForKey2 == null || valueForKey1.equals(valueForKey2)
+            "Values of the 2 keys should be equal, or having a least 1 null value or empty String.",
+            Strings.isNullOrEmpty(valueForKey1) || Strings.isNullOrEmpty(valueForKey2) || valueForKey1.equals(valueForKey2)
         );
     }
 

From c1e429762fbadf5ed4dd54603755dee16300ed21 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Mon, 14 Mar 2022 20:19:00 -0700
Subject: [PATCH 08/13] Add unit test for cluster timeout parameter

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../rest/action/cat/RestNodesAction.java      | 14 +++++--------
 .../rest/action/cat/RestNodesActionTests.java | 21 +++++++++++++++++++
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
index 07bf36e6eee80..bc9e72f9638f6 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
@@ -86,6 +86,8 @@ public class RestNodesAction extends AbstractCatAction {
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(RestNodesAction.class);
     static final String LOCAL_DEPRECATED_MESSAGE = "Deprecated parameter [local] used. This parameter does not cause this API to act "
         + "locally, and should not be used. It will be unsupported in version 8.0.";
+    static final String MASTER_TIMEOUT_DEPRECATED_MESSAGE =
+        "Deprecated parameter [master_timeout] used. To promote inclusive language, please use [cluster_manager_timeout] instead. It will be unsupported in a future major version.";
 
     @Override
     public List<Route> routes() {
@@ -111,7 +113,7 @@ public RestChannelConsumer doCatRequest(final RestRequest request, final NodeCli
         }
         clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
         clusterStateRequest.masterNodeTimeout(request.paramAsTime("cluster_manager_timeout", clusterStateRequest.masterNodeTimeout()));
-        parseDeprecatedMasterTimeoutParam(clusterStateRequest, request);
+        parseDeprecatedMasterTimeoutParameter(clusterStateRequest, request);
         final boolean fullId = request.paramAsBoolean("full_id", false);
         return channel -> client.admin().cluster().state(clusterStateRequest, new RestActionListener<ClusterStateResponse>(channel) {
             @Override
@@ -534,18 +536,12 @@ private short calculatePercentage(long used, long max) {
      * @deprecated As of 2.0, because promoting inclusive language.
      */
     @Deprecated
-    private void parseDeprecatedMasterTimeoutParam(ClusterStateRequest clusterStateRequest, RestRequest request) {
+    private void parseDeprecatedMasterTimeoutParameter(ClusterStateRequest clusterStateRequest, RestRequest request) {
         final String deprecatedTimeoutParam = "master_timeout";
         final String clusterManagerTimeoutParam = "cluster_manager_timeout";
-        final String deprecatedMessage = String.format(
-            Locale.US,
-            "Deprecated parameter [%s] used. To promote inclusive language, please use [%s] instead. It will be unsupported in a future major version.",
-            deprecatedTimeoutParam,
-            clusterManagerTimeoutParam
-        );
         clusterStateRequest.masterNodeTimeout(request.paramAsTime(deprecatedTimeoutParam, clusterStateRequest.masterNodeTimeout()));
         if (request.hasParam(deprecatedTimeoutParam)) {
-            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", deprecatedMessage);
+            deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", MASTER_TIMEOUT_DEPRECATED_MESSAGE);
             request.validateParamValuesAreEqual(deprecatedTimeoutParam, clusterManagerTimeoutParam);
         }
     }
diff --git a/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java b/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java
index 593ad2907797e..ec73cb97136bc 100644
--- a/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java
+++ b/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.rest.action.cat;
 
+import org.opensearch.OpenSearchParseException;
 import org.opensearch.Version;
 import org.opensearch.action.admin.cluster.node.info.NodesInfoResponse;
 import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
@@ -51,6 +52,7 @@
 
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.emptySet;
+import static org.hamcrest.CoreMatchers.containsString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -89,4 +91,23 @@ public void testCatNodesWithLocalDeprecationWarning() {
 
         terminate(threadPool);
     }
+
+    /**
+     * Validate both cluster_manager_timeout and its predecessor can be parsed correctly.
+     * Remove the test along with MASTER_ROLE. It's added in version 2.0.0.
+     */
+    public void testCatNodesWithClusterManagerTimeout() {
+        TestThreadPool threadPool = new TestThreadPool(RestNodesActionTests.class.getName());
+        NodeClient client = new NodeClient(Settings.EMPTY, threadPool);
+        FakeRestRequest request = new FakeRestRequest();
+        request.params().put("cluster_manager_timeout", randomFrom("1h", "2m"));
+        request.params().put("master_timeout", "3s");
+        try {
+            action.doCatRequest(request, client);
+        } catch (OpenSearchParseException e) {
+            assertThat(e.getMessage(), containsString("cluster_manager_timeout"));
+        }
+        assertWarnings(RestNodesAction.MASTER_TIMEOUT_DEPRECATED_MESSAGE);
+        terminate(threadPool);
+    }
 }

From 2d36c8fe78d6943073f8664855ef104cd41dd3fc Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Tue, 15 Mar 2022 06:23:15 +0000
Subject: [PATCH 09/13] Fix unit test by moving assert into try

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../java/org/opensearch/rest/RestRequestTests.java    | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/server/src/test/java/org/opensearch/rest/RestRequestTests.java b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
index b50049f8e7d4b..a8a1488ea5285 100644
--- a/server/src/test/java/org/opensearch/rest/RestRequestTests.java
+++ b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
@@ -295,6 +295,13 @@ public void testValidateParamValuesAreEqual() {
         request.params().put("key2", valueForKey2);
         try {
             request.validateParamValuesAreEqual("key1", "key2");
+            assertTrue(
+                "Values of the 2 keys should be equal, or having a least 1 null value or empty String. Value of key1: "
+                    + valueForKey1
+                    + ". Value of key2: "
+                    + valueForKey2,
+                Strings.isNullOrEmpty(valueForKey1) || Strings.isNullOrEmpty(valueForKey2) || valueForKey1.equals(valueForKey2)
+            );
         } catch (OpenSearchParseException e) {
             assertEquals(
                 "The values of the request parameters: [key1, key2] are required to be equal, otherwise please only assign value to one of the request parameters.",
@@ -304,10 +311,6 @@ public void testValidateParamValuesAreEqual() {
             assertFalse(Strings.isNullOrEmpty(valueForKey1));
             assertFalse(Strings.isNullOrEmpty(valueForKey2));
         }
-        assertTrue(
-            "Values of the 2 keys should be equal, or having a least 1 null value or empty String.",
-            Strings.isNullOrEmpty(valueForKey1) || Strings.isNullOrEmpty(valueForKey2) || valueForKey1.equals(valueForKey2)
-        );
     }
 
     private static RestRequest contentRestRequest(String content, Map<String, String> params) {

From 02e68b59478fd9eff4e5c5c7f17560a702a8c1b5 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Wed, 16 Mar 2022 15:30:54 -0700
Subject: [PATCH 10/13] Modify testValidateParamValuesAreEqual() and test

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../java/org/opensearch/rest/RestRequest.java | 23 +++++++------
 .../org/opensearch/rest/RestRequestTests.java | 34 ++++++++++++-------
 2 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/server/src/main/java/org/opensearch/rest/RestRequest.java b/server/src/main/java/org/opensearch/rest/RestRequest.java
index 75b0723388793..e04d8faa8af39 100644
--- a/server/src/main/java/org/opensearch/rest/RestRequest.java
+++ b/server/src/main/java/org/opensearch/rest/RestRequest.java
@@ -582,26 +582,27 @@ public static XContentType parseContentType(List<String> header) {
     /**
      * The method is only used to validate whether the values of the 2 request parameters "master_timeout" and "cluster_manager_timeout" is the same value or not.
      * If the 2 values are not the same, throw an {@link OpenSearchParseException}.
-     * @param keys Keys of the request parameters.
+     * @param keys Names of the request parameters.
      * @deprecated The method will be removed along with the request parameter "master_timeout".
      */
     @Deprecated
     public void validateParamValuesAreEqual(String... keys) {
-        // Filter the non-empty values of the parameters with the key, and get the distinct values.
-        Set<String> set = new HashSet<>();
+        // Track the last seen value and ensure that every subsequent value matches it.
+        // The value to be tracked is the non-empty values of the parameters with the key.
+        String lastSeenValue = null;
         for (String key : keys) {
             String value = param(key);
             if (!Strings.isNullOrEmpty(value)) {
-                set.add(value);
+                if (lastSeenValue == null || value.equals(lastSeenValue)) {
+                    lastSeenValue = value;
+                } else {
+                    throw new OpenSearchParseException(
+                        "The values of the request parameters: {} are required to be equal, otherwise please only assign value to one of the request parameters.",
+                        Arrays.toString(keys)
+                    );
+                }
             }
         }
-        // If there are more than 1 distinct value of the request parameters, throw an exception.
-        if (set.size() > 1) {
-            throw new OpenSearchParseException(
-                "The values of the request parameters: {} are required to be equal, otherwise please only assign value to one of the request parameters.",
-                Arrays.toString(keys)
-            );
-        }
     }
 
     public static class ContentTypeHeaderException extends RuntimeException {
diff --git a/server/src/test/java/org/opensearch/rest/RestRequestTests.java b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
index a8a1488ea5285..eab187fe020b4 100644
--- a/server/src/test/java/org/opensearch/rest/RestRequestTests.java
+++ b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
@@ -286,30 +286,38 @@ public void testRequiredContent() {
      * The test is added in 2.0 when the request parameter "cluster_manager_timeout" is introduced.
      * Remove the test along with the removal of the non-inclusive terminology "master_timeout".
      */
-    public void testValidateParamValuesAreEqual() {
+    public void testValidateParamValuesAreEqualWhenTheyAreEqual() {
         FakeRestRequest request = new FakeRestRequest();
-        List<String> valueList = new ArrayList<>(Arrays.asList(null, "", "value1", "value2"));
+        List<String> valueList = new ArrayList<>(Arrays.asList(null, "", "value1"));
         String valueForKey1 = randomFrom(valueList);
-        String valueForKey2 = randomFrom(valueList);
+        String valueForKey2 = "value1";
         request.params().put("key1", valueForKey1);
         request.params().put("key2", valueForKey2);
+        request.validateParamValuesAreEqual("key1", "key2");
+        assertTrue(
+            "Values of the 2 keys should be equal, or having a least 1 null value or empty String. Value of key1: "
+                + valueForKey1
+                + ". Value of key2: "
+                + valueForKey2,
+            Strings.isNullOrEmpty(valueForKey1) || valueForKey1.equals(valueForKey2)
+        );
+    }
+
+    /*
+     * The test is added in 2.0 when the request parameter "cluster_manager_timeout" is introduced.
+     * Remove the test along with the removal of the non-inclusive terminology "master_timeout".
+     */
+    public void testValidateParamValuesAreEqualWhenTheyAreNotEqual() {
+        FakeRestRequest request = new FakeRestRequest();
+        request.params().put("key1", "value1");
+        request.params().put("key2", "value2");
         try {
             request.validateParamValuesAreEqual("key1", "key2");
-            assertTrue(
-                "Values of the 2 keys should be equal, or having a least 1 null value or empty String. Value of key1: "
-                    + valueForKey1
-                    + ". Value of key2: "
-                    + valueForKey2,
-                Strings.isNullOrEmpty(valueForKey1) || Strings.isNullOrEmpty(valueForKey2) || valueForKey1.equals(valueForKey2)
-            );
         } catch (OpenSearchParseException e) {
             assertEquals(
                 "The values of the request parameters: [key1, key2] are required to be equal, otherwise please only assign value to one of the request parameters.",
                 e.getMessage()
             );
-            assertNotEquals(valueForKey1, valueForKey2);
-            assertFalse(Strings.isNullOrEmpty(valueForKey1));
-            assertFalse(Strings.isNullOrEmpty(valueForKey2));
         }
     }
 

From 399f2d90568a47f42d8c65b1e306a867666a30d9 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Wed, 16 Mar 2022 15:35:05 -0700
Subject: [PATCH 11/13] Set masterNodeTimeout when the parameter master_timeout
 occurs

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../java/org/opensearch/rest/action/cat/RestNodesAction.java | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
index bc9e72f9638f6..7899909cdebbf 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestNodesAction.java
@@ -538,11 +538,10 @@ private short calculatePercentage(long used, long max) {
     @Deprecated
     private void parseDeprecatedMasterTimeoutParameter(ClusterStateRequest clusterStateRequest, RestRequest request) {
         final String deprecatedTimeoutParam = "master_timeout";
-        final String clusterManagerTimeoutParam = "cluster_manager_timeout";
-        clusterStateRequest.masterNodeTimeout(request.paramAsTime(deprecatedTimeoutParam, clusterStateRequest.masterNodeTimeout()));
         if (request.hasParam(deprecatedTimeoutParam)) {
             deprecationLogger.deprecate("cat_nodes_master_timeout_parameter", MASTER_TIMEOUT_DEPRECATED_MESSAGE);
-            request.validateParamValuesAreEqual(deprecatedTimeoutParam, clusterManagerTimeoutParam);
+            request.validateParamValuesAreEqual(deprecatedTimeoutParam, "cluster_manager_timeout");
+            clusterStateRequest.masterNodeTimeout(request.paramAsTime(deprecatedTimeoutParam, clusterStateRequest.masterNodeTimeout()));
         }
     }
 }

From ae7308c369b8c6131c479e8332d5a44cfacb0a6d Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Thu, 17 Mar 2022 03:34:08 -0700
Subject: [PATCH 12/13] Use assertThrows instead of try catch

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../java/org/opensearch/rest/RestRequestTests.java  | 13 ++++---------
 .../rest/action/cat/RestNodesActionTests.java       |  7 ++-----
 2 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/server/src/test/java/org/opensearch/rest/RestRequestTests.java b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
index eab187fe020b4..cf624ed6c4c57 100644
--- a/server/src/test/java/org/opensearch/rest/RestRequestTests.java
+++ b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
@@ -57,6 +57,7 @@
 
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonMap;
+import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.mockito.Mockito.mock;
@@ -295,7 +296,7 @@ public void testValidateParamValuesAreEqualWhenTheyAreEqual() {
         request.params().put("key2", valueForKey2);
         request.validateParamValuesAreEqual("key1", "key2");
         assertTrue(
-            "Values of the 2 keys should be equal, or having a least 1 null value or empty String. Value of key1: "
+            "Values of the 2 keys should be equal, or having 1 null value or empty String. Value of key1: "
                 + valueForKey1
                 + ". Value of key2: "
                 + valueForKey2,
@@ -311,14 +312,8 @@ public void testValidateParamValuesAreEqualWhenTheyAreNotEqual() {
         FakeRestRequest request = new FakeRestRequest();
         request.params().put("key1", "value1");
         request.params().put("key2", "value2");
-        try {
-            request.validateParamValuesAreEqual("key1", "key2");
-        } catch (OpenSearchParseException e) {
-            assertEquals(
-                "The values of the request parameters: [key1, key2] are required to be equal, otherwise please only assign value to one of the request parameters.",
-                e.getMessage()
-            );
-        }
+        Exception e = assertThrows(OpenSearchParseException.class, () -> request.validateParamValuesAreEqual("key1", "key2"));
+        assertThat(e.getMessage(), containsString("The values of the request parameters: [key1, key2] are required to be equal"));
     }
 
     private static RestRequest contentRestRequest(String content, Map<String, String> params) {
diff --git a/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java b/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java
index ec73cb97136bc..9293d40605f42 100644
--- a/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java
+++ b/server/src/test/java/org/opensearch/rest/action/cat/RestNodesActionTests.java
@@ -102,11 +102,8 @@ public void testCatNodesWithClusterManagerTimeout() {
         FakeRestRequest request = new FakeRestRequest();
         request.params().put("cluster_manager_timeout", randomFrom("1h", "2m"));
         request.params().put("master_timeout", "3s");
-        try {
-            action.doCatRequest(request, client);
-        } catch (OpenSearchParseException e) {
-            assertThat(e.getMessage(), containsString("cluster_manager_timeout"));
-        }
+        Exception e = assertThrows(OpenSearchParseException.class, () -> action.doCatRequest(request, client));
+        assertThat(e.getMessage(), containsString("[master_timeout, cluster_manager_timeout] are required to be equal"));
         assertWarnings(RestNodesAction.MASTER_TIMEOUT_DEPRECATED_MESSAGE);
         terminate(threadPool);
     }

From dfd260d1dbd0f981c10e6a2e1bc6a13c124e4222 Mon Sep 17 00:00:00 2001
From: Tianli Feng <ftianli@amazon.com>
Date: Thu, 17 Mar 2022 15:16:33 -0700
Subject: [PATCH 13/13] put all values directly in RandomFrom in the unit test

Signed-off-by: Tianli Feng <ftianli@amazon.com>
---
 .../org/opensearch/rest/RestRequestTests.java     | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/server/src/test/java/org/opensearch/rest/RestRequestTests.java b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
index cf624ed6c4c57..d5a915b42cf87 100644
--- a/server/src/test/java/org/opensearch/rest/RestRequestTests.java
+++ b/server/src/test/java/org/opensearch/rest/RestRequestTests.java
@@ -48,10 +48,10 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -289,17 +289,18 @@ public void testRequiredContent() {
      */
     public void testValidateParamValuesAreEqualWhenTheyAreEqual() {
         FakeRestRequest request = new FakeRestRequest();
-        List<String> valueList = new ArrayList<>(Arrays.asList(null, "", "value1"));
-        String valueForKey1 = randomFrom(valueList);
+        String valueForKey1 = randomFrom("value1", "", null);
         String valueForKey2 = "value1";
         request.params().put("key1", valueForKey1);
         request.params().put("key2", valueForKey2);
         request.validateParamValuesAreEqual("key1", "key2");
         assertTrue(
-            "Values of the 2 keys should be equal, or having 1 null value or empty String. Value of key1: "
-                + valueForKey1
-                + ". Value of key2: "
-                + valueForKey2,
+            String.format(
+                Locale.ROOT,
+                "The 2 values should be equal, or having 1 null/empty value. Value of key1: %s. Value of key2: %s",
+                valueForKey1,
+                valueForKey2
+            ),
             Strings.isNullOrEmpty(valueForKey1) || valueForKey1.equals(valueForKey2)
         );
     }